ToolComb Blog

Guides that send you to the right tool

How-to articles, category roundups, and fair competitor comparisons for browser-based, privacy-first utilities. Files stay on your device unless a network lookup is the actual job.

GuideImages

Before/After Image Sliders for Portfolios and Renovations

Align two photos, build a drag comparison slider in the browser, and embed results in portfolios - with honest limits on handheld shots.

4 min read

RoundupAudio & Video

Best Free Browser Audio and Video Tools (FFmpeg.wasm)

Trim, join, compress, GIF, MP3, subtitles, and waveform exports without uploading media. How ToolComb's FFmpeg.wasm tools map to real chores - and where ~100 MB and first-load limits apply.

6 min read

RoundupJSON & Data

Best Free CSV, Chart, and File Inspector Tools

Browser-local CSV editing, chart PNG export, bill splits, ZIP listing, and EPUB metadata - no account and honest limits on what each tool can do.

6 min read

RoundupText & Dev

Best Free Developer Text Tools in the Browser

Word counts, diffs, cron, Markdown, slugs, regex replace, SQL format, and JS minify - when to open each ToolComb text tool locally without uploading source.

5 min read

RoundupImages

Best Free Screenshot and Mockup Tools (No Upload)

When to beautify a capture vs drop it in a device frame vs build an OG card - and how ToolComb's Image Editors hub groups mockup tools separately from format converters.

6 min read

GuideBusiness

Bill Splitter Tips for Fair Splits (Tax, Tip, and Shared Items)

Split restaurant bills and group expenses without spreadsheet fights - local math in Bill Splitter.

4 min read

GuideAudio & Video

Burn-In Subtitles from SRT: Limits and Workflow

Hardcode captions in the browser with FFmpeg.wasm when sidecar SRT fails on social or review links. Timing, font, ~100 MB caps, and accessibility tradeoffs.

4 min read

GuideGraphs

CSV to Chart PNG: A Browser Workflow

Clean CSV, paste into Chart Maker, export PNG for slides and docs - without uploading your dataset.

4 min read

GuideImages

Device Frame Mockups Without Figma

Drop a screenshot into a phone or tablet bezel, tune scale and background, and export a marketing PNG - locally, no design subscription.

4 min read

GuideText & Dev

Diff Checker vs Unified Patch - Which Output Do You Need?

Side-by-side diffs for humans, unified patch text for git apply and review bots - when to use each ToolComb tool and how to avoid line-ending surprises.

4 min read

RoundupCAD

DXF vs DWG in the Browser - What ToolComb Can Open

When to use the DXF viewer vs the DWG viewer, what native DWG cannot do in-tab, and how STL preview fits the same CAD hub - honest entity limits, no upload.

6 min read

GuideText & Dev

Find and Replace with Regex Safely in the Browser

Test patterns first, copy before replace, watch greed and backreferences - bulk edit text locally without uploading files or deleting your backup.

4 min read

GuideText & Dev

How Cron Expressions Work in Plain English

Five fields, * and ranges, weekday vs day-of-month traps, and how to build a schedule string in the browser without guessing field order.

4 min read

GuideImages

How to Beautify Screenshots for Docs and Changelogs

Turn raw UI captures into padded, shadowed PNGs for READMEs, release notes, and help centers - in the browser, without upload.

4 min read

GuideJSON & Data

How to Clean CSV Tables in the Browser

Fix headers, delimiters, blank rows, and BOM issues before CSV to JSON or chart export - locally in CSV Editor.

4 min read

GuideImages

How to Generate Open Graph Images for Link Previews

Build a 1200×630 og:image in the browser, wire the tags, and preview the card before you post - without handing art to a random upload site.

4 min read

GuideText & Dev

How to Generate URL Slugs for SEO and APIs

Lowercase, hyphens, unicode pitfalls, stable IDs vs readable paths - generate slugs in the browser and pair with case conversion for code identifiers.

4 min read

GuideAudio & Video

How to Trim and Compress Video Without Uploading

Cut screen recordings and shrink MP4 for Slack, LMS, and email caps using FFmpeg.wasm locally. CRF vs bitrate, ~100 MB limits, and resize when needed.

4 min read

GuideAudio & Video

How to Trim Audio in the Browser (No Upload)

Cut podcast cold opens, song intros, and interview segments with FFmpeg.wasm. First-load size, ~100 MB limits, and when to join or strip silence next.

4 min read

GuideCAD

How to View DXF Files Online Without AutoCAD

Open a .dxf in the browser: drag-and-drop, pan and zoom, layer toggles, fit to view, and PNG export - with honest LINE/ARC/TEXT limits and no upload.

4 min read

GuideSecurity

JWT Generate vs Decode - What Belongs in the Browser

Decode claims locally, generate test tokens with dummy keys - never mint production JWTs or paste live secrets into any website tab.

4 min read

GuideText & Dev

Markdown Editor Live Preview - A Practical Workflow

Split-pane authoring, when to preview vs export, HTML round-trips, and keeping docs local in the browser before you paste into CMS or GitHub.

4 min read

GuideSecurity

MIME Types and HTTP Status Codes - Quick Browser Reference

Look up Content-Type suffixes, decode 4xx vs 5xx in logs, and parse URLs and user agents locally when debugging APIs without tab-hopping.

4 min read

GuideAudio & Video

Mute and Replace Audio Track Safely (Browser)

Swap narration, add licensed music, or strip room tone with FFmpeg.wasm locally. Sync, ~100 MB per file, first-load engine, and copyright you still owe.

4 min read

GuideText & Dev

Regex Named Capture Groups Explained

(?<name>...) syntax, backreferences in replace strings, and debugging named groups in the browser before bulk find-and-replace.

4 min read

GuideImages

Simple Background Removal Limits (Chroma and Flood Fill)

When chroma key and flood fill remove a backdrop in the browser - and when you need ML matting, a green screen, or a real editor instead.

4 min read

GuideCAD

STL Preview for Makers and 3D Print Checks

Orbit STL meshes in the browser before slicing: ASCII/binary support, PNG capture, STEP honesty, and ~80 MB limits - no upload, not a CAD editor.

4 min read

GuideAudio & Video

Video to GIF and Extract Audio Workflows (Browser)

Turn short clips into GIFs or MP3 without uploading. Trim first, respect ~100 MB and FFmpeg first-load, and know copyright limits on extracted tracks.

4 min read

GuideAudio & Video

Waveform PNG Exports for Podcasts and Social Art

Generate square waveform images from MP3 in the browser. Web Audio decode, ~100 MB limits, trim teases first, and licensing for cover art.

4 min read

GuideCAD

Why Native DWG Still Needs Desktop CAD

Browser DWG limits: proprietary binary, version churn, and honest UX vs fake viewers - when to export DXF and what ToolComb can still preview.

4 min read

GuideJSON & Data

ZIP Inspector and EPUB Metadata Basics (What Browser Tools Can See)

List ZIP contents and edit EPUB title/author locally - without treating filename peeks as malware-safe.

4 min read

ComparisonHealth

Army Body Fat Calculator vs Navy Tape: Same Math, Different Job

Hodgdon–Beckett circumference equations power both ToolComb tape pages. What Army AR 600-9 framing adds, what the Navy label means, and why neither is DEXA or a diagnosis.

6 min read

RoundupChemistry

Best Chemistry Calculators for Lab and Homework

Route stoichiometry, molarity, pH, dilution, and gas-law problems to the right ToolComb page. A hub roundup for the chemistry cluster with worked examples and comparison links.

8 min read

RoundupMath

Best Math Calculators for Homework and Engineering

Route algebra, statistics, and geometry problems to the right ToolComb page. A hub roundup for quadratics, fractions, scientific notation, percentages, and standard deviation.

8 min read

RoundupPhysics

Best Physics Calculators for Intro Mechanics

Route force, acceleration, velocity, kinetic energy, and pressure problems to the right ToolComb page. A hub roundup for intro mechanics with SI unit traps and cross-links.

8 min read

GuideFitness

Carbohydrate Calculator: Training Days vs Rest Days in Grams

Plan daily carbohydrate grams from calorie percent or g/kg. AMDR context, higher carbs on hard training days, lower on rest days-and why grams per day is not a medical meal plan.

6 min read

ComparisonChemistry

Concentration Calculator vs Molarity on ToolComb

When to use concentration labels (percent, ppm, mg/L) vs M = n/V vs molality vs dilution. A comparison table for routing chemistry homework to the right tool.

8 min read

ComparisonMath

Confidence Interval vs P-Value: Which Calculator?

Interval estimates vs hypothesis-test evidence, z and t tables, and a comparison table for picking the right statistics tool.

8 min read

RoundupUnits

Digital Unit Converters: Bytes, Angles, and Time

Binary prefixes, Unix timestamps, degrees vs radians, and duration units-when to use the digital hub vs a single converter page.

8 min read

GuideFitness

Fat Intake Calculator: 20% to 35% of Daily Calories in Grams

Turn calorie target and fat percent into grams per day using 9 kcal/g. AMDR context, optional saturated split, and why fat grams are not a lipid prescription.

6 min read

GuideMath

Fraction Calculator: Mixed Numbers, Improper Fractions, and LCD

Convert mixed numbers to improper fractions, simplify with GCF, find LCD, and add or subtract. A homework workflow for fraction calculator mixed numbers problems.

8 min read

GuideHealth

Lean Body Mass Calculator: Boer, James, and Hume Explained

Three regression equations estimate lean mass from height and weight. How ToolComb compares Boer, James, and Hume, when body-fat percent helps, and why LBM is not a DEXA scan.

6 min read

GuideMath

Log Calculator: ln, log10, and Change of Base

Evaluate natural log, base-10 log, and convert between bases with the change-of-base formula. A guide to log calculator natural log base 10 workflows.

8 min read

GuideMath

Matrix Calculator: 2×2 and 3×3 Limits, Determinant, and Inverse

Add, multiply, find determinant and inverse for 2×2 and 3×3 matrices online. What matrix calculator online 2x2 3x3 pages can and cannot do.

8 min read

GuideChemistry

Molality Calculator: When Molarity Misleads

m = n/kg solvent vs M = n/L solution, colligative properties, density bridges, and when to open the molality tool first.

8 min read

GuideHealth

Overweight Calculator: WHO Cutoffs Are Screening, Not a Diagnosis

Adult BMI at or above 25 is WHO overweight screening. How ToolComb’s overweight calculator maps the ladder to 40+, why it is not obesity disease naming, and which sibling tools to open.

6 min read

GuideMath

Percentage Calculator: Three Kinds of Percent Problems

Find percent of a number, what percent one number is of another, and find the whole from a part and percent. A guide to percentage calculator percent of workflows.

8 min read

GuideChemistry

pH Calculator: When the Strong-Acid Assumption Fails

pH = −log[H+], weak acids and Ka, water autoionization at very dilute strong acid, and when to use concentration and molarity tools first.

8 min read

RoundupUnits

Physics Unit Converters for Engineers and Students

Length, pressure, energy, force, and speed converters for SI homework and lab reports-when to use the physics hub vs a single-family page.

9 min read

ComparisonPhysics

Potential Energy vs Kinetic Energy: Which Page?

PE = mgh vs KE = ½mv², energy conservation, and a comparison table for picking the right ToolComb physics tool.

8 min read

GuideMath

Probability Calculator: AND, OR, and Binomial

Compute P(A and B), P(A or B), complements, and binomial probabilities. A guide to probability calculator and or problems with independent events.

8 min read

RoundupFitness

Best Fitness Calculators for Runners and Lifters (ToolComb Hub)

When to open pace vs one-rep max vs heart-rate zones vs MET calories - and how ToolComb's Fitness Calculators hub groups training tools separately from wellness screening.

8 min read

ComparisonPhysics

Force, Pressure, Kinetic Energy: Which Physics Calculator?

F=ma vs P=F/A vs KE=½mv² vs P=E/t, unit traps (kg vs g), and a comparison table for picking the right ToolComb physics tool.

8 min read

GuideFitness

Macro Calculator: Split Protein, Carbs, and Fat by Percent

How ToolComb turns daily calories into grams of protein, carbohydrate, and fat using Atwater factors. 40/30/30 vs 50/30/20 teaching examples, TDEE input quality, and why percent splits are not a diet prescription.

8 min read

GuideMath

Scientific Notation for Engineers and Students

a×10^n, engineering prefixes, significant figures, E notation on calculators, and very large or small numbers- with a browser workflow.

9 min read

ComparisonMath

Standard Deviation vs Z-Score: Which Calculator When Homework Asks

Sample vs population SD, z = (x−μ)/σ, percentiles, and a comparison table for spread versus how unusual one value is.

10 min read

GuideFitness

Weight Watchers Points Calculator (Unofficial - Not Affiliated With WW)

Legacy Points from calories, fat grams, and fiber using a published classroom formula. ToolComb is not WeightWatchers; SmartPoints differ. Educational arithmetic only - not a WW membership substitute or medical advice.

7 min read

RoundupHealth

Wellness Calculators: BMI, BMR, and Body Composition (ToolComb Hub)

How ToolComb's Wellness Calculators hub differs from Fitness Calculators - screening vs training tools, BMI and BMR limits, tape body fat, pregnancy due dates, and why BAC math is not a drive-home plan.

9 min read

GuideValidators

A JSON Validator Is Not JSON Schema (RFC 8259 vs a Contract)

Valid JSON can still be the wrong document. Syntax (RFC 8259) is not draft 2020-12 schema. When to open ToolComb’s JSON validator, JSON Schema validator, or formatter - and what duplicate keys still hide.

7 min read

GuideValidators

A Luhn Checksum Is Not a Payment (and Not a Card Generator)

The Luhn algorithm and an IIN brand guess are a format check. They do not charge a card, prove the PAN is issued, or store numbers. Use published test PANs. Never paste live production card data.

7 min read

ComparisonMath

GCF vs LCM: Which Calculator When Homework Asks

GCD/HCF vs LCM, prime factorization, and adding fractions with unlike denominators. A comparison table for picking the right ToolComb tool.

9 min read

GuideChemistry

Half-Life Decay: Remaining Amount Formula and Solving for Any Variable

Use N=N0(1/2)^(t/t½) for remaining amount, solve for half-life or time, and know nuclear vs pharmacokinetic first-order decay. Log rearrangement with ToolComb tools.

9 min read

ComparisonValidators

JSON vs JSON5: What Validators Accept (and What APIs Will Reject)

JSON5 allows comments, unquoted keys, trailing commas, and single quotes. RFC 8259 does not. How ToolComb’s JSON validator and JSON5 validator disagree on purpose, and when Infinity becomes null.

7 min read

GuideFitness

METs and Calories Burned: What the Number Means

MET × kg × hours estimates session energy from Compendium averages. How ToolComb's calories burned calculator relates to BMR and TDEE - and why your watch may disagree.

7 min read

GuideFitness

One-Rep Max Formulas: What Epley and Brzycki Assume

Epley and Brzycki turn a submax set into a 1RM estimate. ToolComb caps reps at 12, shows both formulas, and prints %1RM loads - with honest limits for beginners and bad form.

7 min read

GuideFitness

Pace vs Speed: What Running Calculators Actually Measure

Pace is minutes per distance; speed is distance per hour. How ToolComb's pace calculator solves two of three (pace, time, distance), why treadmill mph is not outdoor pace, and where race projections come from.

9 min read

GuideFitness

Protein Grams per kg: What the Calculator Can and Cannot Say

Sedentary 0.8 g/kg vs strength 1.6 g/kg, lean mass vs total weight, and kidney caveats. ToolComb's protein calculator is a range estimate - not a meal plan or medical nutrition prescription.

8 min read

GuideMath

Pythagorean Theorem: Find the Missing Side (Hypotenuse and Legs)

Use a²+b²=c² to find a missing side, spot the hypotenuse, recognize 3-4-5 triples, and connect distance in 2D. Common student errors and which calculator to open.

9 min read

GuideMath

Quadratic Formula, Discriminant, and Roots: When Factoring Fails

Solve ax²+bx+c=0 with the discriminant b²−4ac, real vs complex roots, and the vertex. A homework workflow for when factoring does not work.

9 min read

ComparisonChemistry

Stoichiometry vs Molarity: Which Calculator for Which Problem

Mole ratios vs M=n/V, limiting reagent, and why dilution is C1V1=C2V2-not stoich. A comparison table for picking the right ToolComb chemistry tool.

9 min read

ComparisonFitness

Target Heart Rate: 220−Age vs Karvonen (and Tanaka)

Fox 220−age, Tanaka 208−0.7×age, and Karvonen with resting HR produce different zone numbers. How ToolComb's target heart rate calculator compares them - and why none replaces a stress test.

7 min read

GuideValidators

Well-Formed XML Is Not XSD (and Not an XML Bomb Test)

DOMParser can tell you tags nest. It cannot apply your XSD, load a DTD, or prove a SOAP body is the right message. How ToolComb’s XML validator differs from XML-to-JSON and from schema.

7 min read

GuideHealth

BMR vs TDEE vs Calories Burned: Three Numbers, Three Jobs

Mifflin–St Jeor BMR is not TDEE, and TDEE is not a MET session. How ToolComb splits the calorie calculator, the BMR calculator, and calories burned - and why none of them is a meal plan.

8 min read

GuideHealth

Due Date Is Naegele’s Rule, Not an Ultrasound

LMP + 280 days is a teaching estimate (cycle-length optional). It is not a crown–rump measurement, not a conception timestamp, and not medical advice. How ToolComb’s due date calculator works and when it is the wrong clock.

7 min read

ComparisonHealth

Healthy Weight vs Ideal Weight: WHO Band vs Devine and Friends

Healthy weight on ToolComb is the adult BMI 18.5–24.9 interval from height. Ideal body weight (Devine, Robinson, Miller, Hamwi) is a dosing-era point estimate. They are not the same number and neither is a personal goal.

7 min read

GuideHealth

Navy Body Fat vs DEXA: What a Tape Measure Can and Cannot Claim

Hodgdon–Beckett / US Navy circumference estimates are not DEXA, not a Bod Pod, and not an eating-disorder diagnosis. How ToolComb’s body-fat and Army tape tools work, where they fail, and what to open instead of BMI.

7 min read

GuideHealth

Why BMI Is Not a Diagnosis (Athletes, Age, and WHO Bands)

Adult BMI is kg/m² and a WHO screening label. It does not diagnose disease, malnutrition, or an eating disorder. How the formula works, who it misses, and which ToolComb tool to open.

7 min read

GuideHealth

Why You Should Not Use a BAC Calculator to Decide Whether to Drive

Widmark’s classroom formula is not a breathalyzer, not legal advice, and not a ride-home plan. What ToolComb’s BAC page actually computes, why food and timing break it, and what it will not help you do.

7 min read

ComparisonBusiness

Canva vs Novoresume vs ToolComb: Resume Builders Compared

Canva is a design file. Novoresume-class sites are career SaaS with accounts. ToolComb is a no-signup browser layout. When each is the right resume tool - and when you are the product.

7 min read

GuideBusiness

Why ATS Software Rejects Your Resume PDF

Columns, icons-as-headings, and image-only PDFs. What applicant tracking systems actually parse, when a designed resume is fine, and how to keep work history off a career-site account.

7 min read

GuideBusiness

Why Your Barcode Won’t Scan (Quiet Zone, Format, and Check Digits)

Code128 vs EAN-13 vs UPC, printers that bleed, guns that expect another symbology. Generate a 1D barcode in the browser - drawing bars is not a GS1 license.

7 min read

ComparisonSecurity

Password Generator vs Password Manager: Random Strings Are Not Storage

A generator makes one strong secret. A manager remembers unique secrets per site. Why you still need both, and why an online generator that phones home is the wrong half.

7 min read

ComparisonBusiness

Regex101 vs ToolComb: A Debugger vs a Quick In-Browser Test

Regex101 is the dialect-aware debugger people bookmark. Compare that with a no-account tester on ToolComb - and why production logs should not be the sample set.

13 min read

GuideJSON & Data

Why XML to JSON Looks Wrong (Attributes, Text, and Arrays of One)

XML is a document tree. JSON is typed values. Why converters invent `#text` keys, wrap singles in arrays, and drop namespaces - and how to inspect the result locally.

7 min read

GuideBusiness

Why Your QR Code Won’t Scan (Print, Contrast, and Payload Size)

Finder patterns, error correction, logos, and glossy lamination. Generate a scannable code in the browser - a QR is not encryption.

11 min read

GuideUnits

Why Your Unix Timestamp Is Off by Hours (or 55 Years)

Seconds vs milliseconds, UTC vs local, and Excel serial dates. How to convert an instant in the browser without uploading a log dump.

11 min read

GuidePDF

Should You Unlock a PDF Online? Why Password Removers Are a Trap

Uploading a password-protected PDF to a ‘remove password’ site gives the vendor the file and often the password. When the real job is compress/split locally, and when you still need Acrobat.

15 min read

GuideNetworking

Why Chrome Says “Not Secure” (and What to Check First)

HTTP pages, mixed content, name-mismatch certificates, and expired TLS. How to tell a padlock problem from a DNS problem without scanning hosts you do not own.

12 min read

GuideJSON & Data

Why CSV to JSON Keeps Failing (Quotes, Excel, and Encoding)

Trailing commas, European separators, UTF-8 BOM, and quoted commas. How to get a JSON array without uploading a customer export.

13 min read

GuideSEO

Why Google Shows a Different Title Than Your Title Tag

Google rewrites title tags from H1s, sitelinks, and brand. How to see the live tags, preview a SERP snippet, and when a rewrite is a bug versus a better click.

13 min read

GuideImages

Why WebP Images Won’t Open in Outlook (and Older CMS Uploads)

WebP is fine on the web and hostile in email clients. When to convert to JPG or PNG in the browser instead of uploading Camera Roll to a converter ad.

10 min read

GuideNetworking

How to Check Security Headers on a Live Site

CSP, HSTS, X-Frame-Options, cookies, and noindex - what to look for in HTTP headers, how a header viewer helps, and what it will never prove.

7 min read

GuidePDF

How to Turn Screenshots Into a PDF for a Bug Report

Capture, convert PNG/JPG, merge pages, compress - in the browser - so a repro PDF does not upload customer PII to a random converter.

7 min read

GuideCSS & Frontend

Why Your Favicon Isn’t Updating in the Browser Tab

You replaced favicon.ico and the old icon is still there. Caches, HTML link tags, SVG vs ICO, and how to generate a new set without an account.

7 min read

GuideSecurity

Base64 Is Not Encryption: Encoding vs Secrets

Base64 hides nothing. Why people treat it like a cipher, what it is actually for (data URLs, JWTs, APIs), and how to encode or decode in the browser without uploading a key.

7 min read

ComparisonImages

Convertio vs ToolComb: Cloud Format Hub vs Browser Tools

Convertio converts hundreds of formats in the cloud. Compare that with ToolComb’s no-account, in-browser PDF, image, and JSON tools - and when an upload is required.

8 min read

GuidePDF

How to Send a PDF When You Can’t Use Google Drive

No Drive, no Dropbox, no ‘anyone with the link.’ How to shrink, split, and email a PDF locally - and when a contracted portal is the real answer.

7 min read

ComparisonImages

ILoveIMG vs ToolComb: Cloud Image Suite vs Browser Tools

ILoveIMG is iLovePDF’s image sibling: compress, resize, convert in the cloud. Compare that with ToolComb’s no-upload compressor, HEIC/WebP/SVG converters, and PDF tools on the same site.

7 min read

GuideSEO

Why Slack and Facebook Show the Wrong Link Preview Image

Open Graph caches, relative URLs, 1200×630 crops, and SPA titles. How to see what crawlers see and fix the card without guessing.

7 min read

GuideNetworking

Why Your DNS Change Isn’t Showing Yet

You updated A or CNAME records but the site still hits the old server. TTL, cache, recursive resolvers, and how to look up public DNS without confusing it with your laptop’s cache.

7 min read

GuideSEO

A Pre-Launch Checklist for a New Web Page

Title tags, meta description, Open Graph, SERP snippet, favicon, bundle weight, lazy-load, and a first accessibility pass - before you ship, without a login.

7 min read

GuidePDF

Client-Side vs Cloud File Conversion: When Each Makes Sense

Browser (WASM/JS) conversion keeps the file on the device. Cloud APIs handle OCR, huge files, and 400 formats. How to choose - and what ToolComb actually does.

7 min read

GuidePDF

Email Attachment Size Limits and How to Shrink the File

Gmail is 25 MB. Outlook is often lower. How to compress PDFs and images, when to split, and how to stay under the cap without uploading the attachment to a random site.

7 min read

GuidePDF

Are Online PDF Converters Safe?

What happens when you upload a contract or ID to a free PDF site. When a browser-local converter is enough, and when you still need Acrobat.

7 min read

ComparisonJSON & Data

JSONLint vs ToolComb JSON Formatter: Validate vs a JSON Toolkit

JSONLint is the classic validator. Compare it with a browser-local formatter, tree viewer, minifier, and graph - and when not to paste a production payload.

7 min read

ComparisonSecurity

JWT.io vs a Browser JWT Decoder: Where to Read a Token

jwt.io is the default debugger. Compare that with a no-account, browser-local decoder when the token might be a live access token.

7 min read

ComparisonPDF

Sejda vs PDF2Go vs ToolComb: Which PDF Toolkit?

Sejda and PDF2Go are full cloud PDF suites. Compare OCR, accounts, and uploads with ToolComb’s browser-local compress, split, merge, and convert tools.

7 min read

ComparisonImages

TinyPNG vs Squoosh vs ToolComb: Image Compression Compared

TinyPNG is the cloud default. Squoosh is Google’s in-browser lab. See how a no-account compressor on ToolComb compares for everyday JPG and PNG work.

7 min read

GuideSecurity

What Not to Paste Into Online Developer Tools

JWTs, API keys, customer JSON, and password checkers: a practical list of what to keep off random websites, and which jobs can stay in the browser.

7 min read

GuideImages

Why iPhone Photos Won’t Open on Windows (HEIC Explained)

HEIC is Apple’s default photo format. Why Paint and older apps reject it, when to convert to JPG or PNG, and how to do it in the browser without an iCloud upload.

7 min read

RoundupImages

Best Free Image Converter and Compression Tools

The best free browser image tools for compress, HEIC, WebP, SVG, PNG, and JPG - no upload and no account.

5 min read

RoundupPDF

Best Free PDF Tools Online That Do Not Upload Your Files

A map of ToolComb’s free PDF tools that run in the browser: compress, split, merge, convert. No account.

6 min read

ComparisonPDF

ToolComb vs iLovePDF: Privacy, Features, and When to Use Each

iLovePDF is a full cloud PDF suite. ToolComb runs split, merge, compress, and convert in your browser so files are not uploaded.

4 min read

ComparisonPDF

ToolComb vs SmallPDF: Browser Tools vs a Cloud PDF Suite

SmallPDF is a polished cloud PDF product. See how a no-upload, no-account browser toolkit compares for everyday PDF jobs.

4 min read

GuideProduct

What Is ToolComb? Every Tool Category, Explained

ToolComb is a free, no-account toolkit of 112 browser-based developer utilities. This guide walks through JSON, PDF, image, security, networking, SEO, CSS, calculators, and the rest - including what stays on your device.

13 min read

RoundupSecurity

Best Free Security and Encoding Tools

Decode JWTs, hash files, generate passwords, and strip metadata locally. Security utilities that keep tokens and passwords on your device.

6 min read

RoundupJSON & Data

Best JSON Tools for Developers

Format, view, minify, and graph JSON in the browser. A privacy-first toolkit for API debugging without pasting secrets to a site.

5 min read

ComparisonPDF

ToolComb vs Adobe Acrobat Online: Free Local Tools vs Paid Cloud

Acrobat is the professional standard. ToolComb covers common PDF tasks locally when you do not want a subscription or a cloud upload.

4 min read

ComparisonPDF

ToolComb vs TinyWow: All-in-One Utilities Compared

TinyWow packs many utilities in one site. Compare that model with ToolComb’s browser-only, privacy-first tools for files and developers.

4 min read

RoundupScience

Best Scientific Calculators for Chemistry and Physics

Molarity, pH, gas law, force, and energy calculators for lab and class. Run the math in your browser with worked examples.

5 min read

RoundupUnits

Best Unit Converters for Students and Engineers

Length, temperature, bytes, Unix time, pressure, and more - fast unit converters that work offline in your browser.

5 min read

ComparisonImages

ToolComb vs CloudConvert: Client-Side vs Cloud Conversion

CloudConvert is built for heavy cloud conversion and APIs. ToolComb is for private, in-browser PDF, image, and data conversion.

4 min read

ComparisonJSON & Data

ToolComb vs JSONFormatter.org: JSON Tools Compared

JSONFormatter.org is a classic JSON utility. See how ToolComb’s formatter, viewer, minifier, and graph tools compare for private payloads.

4 min read

RoundupCSS & Frontend

Best CSS and Frontend Design Tools

Color palettes, CSS animation previews, favicons, patterns, bundle size, and screen-reader checks - all in the browser.

4 min read

RoundupSEO

Best Free SEO Preview Tools

Audit meta tags, Open Graph, and SERP snippets before you ship. Free SEO preview tools with no login.

4 min read

ComparisonPDF

iLovePDF vs SmallPDF vs ToolComb: Which PDF Toolkit?

Three ways to edit PDFs online: two cloud suites and a browser-only toolkit. Choose by privacy, price, and features.

4 min read

ComparisonJSON & Data

ToolComb vs CodeBeautify: Developer Toolkit Comparison

CodeBeautify is a large developer toolbox. Compare breadth, privacy, and in-browser processing with ToolComb’s focused tools.

7 min read

ComparisonPDF

Adobe Acrobat vs Free Privacy-First PDF Tools

When you need Acrobat, and when a free local PDF compressor, splitter, or merger in the browser is enough.

4 min read

RoundupBusiness

Best Free Business Tools for Freelancers

Resume, invoice, QR, barcode, and profile card tools that keep client and personal data on your device.

6 min read

RoundupNetworking

Best Free Networking Diagnostic Tools

DNS, SSL, ping, headers, and IP lookups for debugging. Clear notes on what must leave your browser to query the public internet.

6 min read

ComparisonJSON & Data

TinyWow vs CodeBeautify vs ToolComb: All-in-One Tool Sites

All-in-one tool sites vs a privacy-first browser toolkit. What to use for files, JSON, and everyday developer chores.

4 min read

GuidePDF

How to Compress a PDF for Email Without Uploading It

Shrink a PDF in the browser so it fits Gmail or Outlook limits. No account, no upload to finish the job.

4 min read

GuideImages

How to Compress Images for the Web Without Ruining Quality

Shrink JPG/PNG for faster pages. Compression stays in the browser.

4 min read

GuidePDF

How to Split a PDF Into Separate Files (By Page or Range)

Split a PDF by page, range, or interval in the browser. No watermark, no cloud copy to finish the cut.

4 min read

GuideImages

JPG vs PNG vs WebP: Which Image Format Should You Use?

Pick a format for photos, UI, and transparency, then convert locally.

4 min read

GuideImages

How to Convert HEIC Photos to PNG

A PNG copy of an iPhone photo for editing, done on-device.

4 min read

GuideImages

How to Convert iPhone HEIC Photos to JPG

Make iPhone photos work in apps that reject HEIC, without a cloud album.

4 min read

GuidePDF

How to Delete Pages From a PDF Without Adobe Acrobat

Remove extra PDF pages in the browser. No Acrobat subscription, no third-party upload.

4 min read

GuidePDF

How to Merge Multiple PDFs Into One File

Combine PDFs in reading order in the browser. No Adobe, no cloud locker, no account.

4 min read

GuidePDF

How to Add Page Numbers to a PDF Online

Stamp page numbers with position and start index. Processed in the browser, no account.

4 min read

GuideImages

How to Convert WebP Images to JPG for Compatibility

Convert WebP when a CMS or app still wants JPG.

4 min read

GuideImages

How to Convert WebP to PNG

WebP to PNG locally for editing workflows.

4 min read

GuidePDF

How to Reorder and Sort PDF Pages in Your Browser

Fix scanned page order in the browser. No cloud copy of the packet.

4 min read

GuidePDF

How to Convert a PDF to JPG for Sharing and Slides

Turn PDF pages into JPGs in the browser for email, chat, and decks.

4 min read

GuidePDF

How to Convert a PDF to PNG Without Losing Sharpness

Export PDF pages as PNG when JPEG artifacts smear text. Convert in the browser.

4 min read

GuideImages

How to Convert JPG to PNG for Editing

Convert JPG to PNG before heavy edits. No upload.

4 min read

GuideImages

How to Convert PNG to JPG to Shrink File Size

Drop huge PNG screenshots to JPG when you do not need transparency.

4 min read

GuidePDF

How to Combine Images Into a Single PDF

Turn a mixed stack of photos or scans into one PDF in the browser. No account.

4 min read

GuideImages

How to Convert SVG Graphics to PNG

Rasterize logos and icons to PNG at the size you need.

4 min read

GuideImages

How to Convert SVG to JPG

Vector to JPG for email and CMS fields that reject SVG.

4 min read

GuidePDF

How to Extract Images From a PDF on Your Device

Turn PDF pages into images on your device. No upload. Choose JPG or PNG for the handoff.

4 min read

GuideImages

How to Convert a GIF to a Still JPG or PNG

Capture a GIF’s first frame as a still image locally.

4 min read

GuidePDF

How to Convert JPG Photos to PDF on Any Device

Make a PDF from JPG photos in the browser. No install, no account.

4 min read

GuidePDF

How to Convert PNG Screenshots to PDF

Bundle PNG screenshots into one PDF in the browser. No account, no upload to finish the handoff.

4 min read

GuideImages

How to Place Text Behind a Subject in an Image

Thumbnail and poster type-behind-subject effects in the browser.

4 min read

GuideNetworking

How DNS Records Work: A, AAAA, MX, CNAME, and TXT

Read public DNS records to debug domains. Lookups send the hostname to resolve them.

5 min read

GuideSEO

How to Audit Meta Tags on Any Page

Title, description, canonical, and robots - extract and review before launch.

4 min read

GuideBusiness

How to Build a Resume in Your Browser (No Account)

Write and export a resume without uploading work history to SaaS.

6 min read

GuideCSS & Frontend

How to Build a UI Color Palette

Pick primaries, tints, and contrast-safe pairs in the browser.

4 min read

GuideScience

How to Calculate Acceleration (With Examples)

Use a = Δv / t with worked problems. Run the numbers locally in a browser calculator.

4 min read

GuideScience

How to Calculate Velocity From Distance and Time

Average velocity problems for class and lab. Calculate in the browser with unit care.

4 min read

GuideUnits

How to Convert Length Units (Metric and Imperial)

Convert metres, feet, inches, and miles accurately in the browser.

4 min read

GuideUnits

How to Convert Temperature Between Celsius, Fahrenheit, and Kelvin

Temperature scales with the right formulas and a local converter.

4 min read

GuideBusiness

How to Create a Professional Invoice Without Excel

Freelance invoices in the browser; client data stays local.

5 min read

GuideJSON & Data

How to Explore Nested JSON Without Getting Lost

Tree view tactics for large payloads.

4 min read

GuideNetworking

How to Find a Website's IP Address

Resolve a hostname to A/AAAA addresses for debugging.

4 min read

GuideJSON & Data

How to Format and Validate JSON From an API Response

Pretty-print and catch syntax errors locally after a messy paste.

4 min read

GuideSecurity

How to Generate a Strong Password in the Browser

High-entropy passwords generated on-device. Nothing sent to a server.

5 min read

GuideSecurity

What Is a JWT? How to Decode a Token Without Sharing It

Header, payload, signature - decode locally so tokens never hit a website.

5 min read

GuideCSS & Frontend

How CSS Animations Work (and How to Preview Them)

Keyframes, easing, and reduced-motion - preview before you paste into a codebase.

4 min read

GuideSEO

How Open Graph Tags Control Link Previews

og:title, og:image, and twitter cards - preview before you post.

4 min read

GuideBusiness

How QR Codes Work (and How to Generate One)

QR basics and local generation for URLs, Wi-Fi, and vCards.

5 min read

GuideNetworking

How SSL Certificates Work and How to Check Expiry

TLS basics and a public certificate check. The hostname is sent to complete the lookup.

4 min read

GuideScience

How to Calculate Force With F = ma

Newton’s second law with examples. Local force calculator for physics homework and checks.

4 min read

GuideScience

How to Calculate Kinetic Energy

KE = ½mv² explained, with unit conversion notes and a browser calculator.

4 min read

GuideSecurity

How to Check Password Strength Before You Reuse It

Strength analysis in the browser. The password is not stored or transmitted.

4 min read

GuideUnits

How to Convert Bytes, Bits, KB, MB, and GB

SI vs binary prefixes for storage. Convert locally while debugging downloads.

4 min read

GuideUnits

How to Convert Unix Timestamps to Human Dates

Seconds vs milliseconds, UTC vs local, converted in the browser.

4 min read

GuideBusiness

How to Design a Digital Profile Card

Shareable profile cards with no design subscription.

5 min read

GuideJSON & Data

How to Minify JSON for Production Payloads

Strip whitespace locally before you ship.

4 min read

GuideNetworking

How to Read HTTP Headers When Debugging a Site

Cache, cookies, CORS, and security headers from a live response.

4 min read

GuideJSON & Data

How to Visualize JSON as a Graph

Nested JSON as an interactive graph in the browser.

4 min read

GuideSecurity

MD5 vs SHA-1 vs SHA-256: What Hashes Are For

Hashing vs encryption, collisions, and local checksums.

5 min read

GuideScience

How to Calculate Density From Mass and Volume

Density formula, units, and lab-style examples you can compute in the browser.

4 min read

GuideScience

How to Calculate Potential Energy

Gravitational potential energy problems and a local calculator for classwork.

4 min read

GuideJSON & Data

How to Convert CSV to JSON for APIs and Scripts

Spreadsheets to JSON arrays, locally.

4 min read

GuideUnits

How to Convert Speed Units (mph, km/h, m/s)

Speed conversions for class, travel, and physics checks.

4 min read

GuideBusiness

How to Convert Text Case: Title, Camel, Snake, and More

Naming conventions and headlines, converted locally.

4 min read

GuideJSON & Data

How to Convert XML to JSON for Modern Apps

Legacy XML to JSON without an upload.

4 min read

GuideSecurity

How to Decode URL-Encoded Query Strings

Percent-encoding and query params, decoded locally while debugging.

4 min read

GuideSecurity

How to Encode and Decode Base64 (Without a Server)

Data URLs, tokens, APIs - encode and decode privately.

5 min read

GuideBusiness

How to Generate Barcodes for Inventory and Labels

Barcode types and on-device labels.

5 min read

GuideCSS & Frontend

How to Generate Favicons for Every Browser

ICO, PNG, Apple touch, and SVG favicons from one source image.

4 min read

GuideNetworking

How to Run a Ping Test and Read Latency

What ping measures, what it does not, and how to read the result.

4 min read

GuideSEO

How to Write Title Tags and Meta Descriptions That Get Clicks

SERP length, intent, and a snippet preview before you ship.

4 min read

GuideUnits

Mass vs Weight: How to Convert Them Correctly

Mass and weight are not the same. Convert each family with the right tool.

4 min read

GuideNetworking

What Reverse DNS (PTR) Records Tell You

PTR lookups map IPv4 to a hostname. The address is sent to perform the lookup.

4 min read

GuideNetworking

A Practical WCAG Checklist You Can Run in the Browser

Accessible names, contrast, and structure checks you can run while you build.

4 min read

GuideNetworking

How Lazy Loading Images Affects Page Speed

Lazy-load vs LCP trade-offs, with a browser tester for your markup.

4 min read

GuideCSS & Frontend

How Screen Readers Interpret Your HTML

Headings, labels, and alt text as a screen reader would announce them.

4 min read

GuideScience

How to Calculate Power (Electrical and Mechanical)

Watts, horsepower, and P = IV / P = W/t. Browser calculator for engineering checks.

4 min read

GuideScience

How to Calculate Pressure From Force and Area

P = F/A with real examples. Calculate locally.

4 min read

GuideUnits

How to Convert Energy and Power Units

Joules, calories, watts, and horsepower without mixing energy and power.

4 min read

GuideBusiness

How to Convert HTML to Markdown (and Back)

CMS HTML to Markdown without sending drafts out.

5 min read

GuideUnits

How to Convert Pressure Units (psi, bar, Pa, atm)

Tire gauges, labs, and weather maps use different pressure units.

4 min read

GuideJSON & Data

How to Convert YAML Config to JSON

YAML configs to JSON for tools that only accept JSON.

4 min read

GuideSecurity

How to Encode HTML Entities and Avoid XSS Pitfalls

Entity encoding for safe HTML display.

5 min read

GuideJSON & Data

How to Turn a Byte Array Into an Image

Preview embedded bitmap arrays in the browser.

4 min read

GuideSEO

On-Page SEO for Tool Pages and Landing Pages

Titles, canonicals, FAQs, and internal links that help a tool site rank.

4 min read

GuideSecurity

UUID Versions Explained: v1, v3, v4, and v5

Pick a UUID version and generate IDs locally.

5 min read

GuideBusiness

What Lorem Ipsum Is For (and How to Generate It)

Placeholder text for mockups, generated locally.

4 min read

GuideBusiness

A Freelance Document Workflow That Never Uploads Client Files

Resume, invoice, PDF, and image steps that stay local.

5 min read

GuideScience

How to Calculate Molarity of a Solution

Molarity formula, worked lab examples, and a local calculator for solution prep.

4 min read

GuideJSON & Data

How to Convert a Bitmap Image to a Byte Array

Pixels to arrays for embedded work.

4 min read

GuideUnits

How to Convert Area, Volume, and Density Units

m², litres, and kg/m³ conversions that stay consistent.

4 min read

GuideSecurity

How to Convert Binary, Decimal, Hex, and Octal

Number bases for debugging and coursework, converted on-device.

4 min read

GuideJSON & Data

How to Convert Time Across Time Zones Accurately

Avoid DST mistakes with a local timezone converter.

4 min read

GuideBusiness

How to Test Regular Expressions Before You Ship Them

Test regex against real strings in the browser.

5 min read

GuideScience

How to Use the Ideal Gas Law (PV = nRT)

Rearrange PV = nRT, watch units, and solve for unknowns locally.

4 min read

GuideGraphs

How to Visualize Tree Data Structures

Org charts, file trees, and nested JSON as a tree you can inspect locally.

4 min read

GuideUnits

MPG vs L/100km and Other Fuel Efficiency Units

US MPG, UK MPG, and L/100km are not the same formula.

4 min read

GuideSecurity

What File Metadata Reveals About You

EXIF GPS, authors, software tags - inspect before you share.

5 min read

GuideGraphs

When to Use a Heatmap in UX and How to Simulate One

Heatmaps for layouts and click hypotheses - simulate patterns without analytics export.

4 min read

GuideSecurity

A Practical Privacy Checklist Before You Share a File

Metadata, PDFs, and cloud converters: a local-tool checklist.

5 min read

GuideScience

How to Calculate Molecular Weight

Sum atomic masses correctly and check the result with a browser molecular weight tool.

4 min read

GuideJSON & Data

How to Fix Invalid JSON (Commas, Quotes, and Trailing Junk)

Common parse errors and a local formatter once it is valid.

4 min read

GuideSecurity

How to Remove EXIF and Document Metadata Before Sharing

Strip location and author data in the browser.

5 min read

GuideJSON & Data

JSON vs XML vs YAML vs CSV: When to Use Each

Pick a format, then convert locally when you need another shape.

4 min read

GuideScience

Molarity vs Molality: How to Calculate Both

When chemists use molality vs molarity, plus local calculators for both.

4 min read

GuideScience

How to Calculate pH From Concentration

pH, pOH, and strong-acid approximations with a local pH calculator.

4 min read

GuideScience

How to Do Dilution Calculations (C1V1 = C2V2)

Stock-to-working concentration math for labs. Dilute locally with a calculator.

4 min read