# Add Watermark to PDF - Text or Image Online Free Stamp custom text or a PNG logo on every page or a range - entirely in your browser, 50 MB max. ### Upload PDF Loading PDF tools... ### Watermark Settings Watermark type Watermark text _CONFIDENTIAL_ Font size (pt) _48_ Opacity (%) _30_ Diagonal preset (-45°) Pages to watermark Apply Watermark Reset All ### Result No watermarked PDF yet Upload a PDF, configure settings, and click Apply Watermark ## What Is a PDF Watermark Tool? A **PDF watermark tool** stamps semi-transparent text or an image across each page to signal draft status, confidentiality, or brand ownership. Unlike printing a giant word on paper before scanning, a digital watermark layers on top of existing vectors and images without re-rasterizing them. This page uses local PDF processing for text stamps and local image placement plus `drawImage` for logo overlays. The watermark sits in the page content stream above body text but below nothing - recipients see it in every viewer that honors standard PDF drawing operators. Watermarks are a communication device, not encryption. Anyone with Acrobat can sometimes remove a simple overlay by editing the content stream, so treat text watermarks as deterrence for casual sharing - not DRM. For sensitive data, combine watermarking with access controls, password protection, organizational policy, and legal agreements. This tool makes honest drafts easy: stamp CONFIDENTIAL at 30% opacity on an investor deck before emailing partners, or place a low-opacity logo on photography portfolio PDFs so forwarded copies still show your brand. Watermarking differs from headers, page numbers, and compression. Headers and footers repeat small text in margins; watermarks typically span the page center at an angle. Compression re-encodes images to shrink file size - it does not add visible stamps. If you need running folios, use [PDF page numbers](https://www.toolcomb.com/pdf-page-numbers) or [PDF headers & footers](https://www.toolcomb.com/pdf-headers-footers) alongside or instead of a diagonal CONFIDENTIAL stamp. Processing runs entirely in your browser. the browser PDF reader counts pages via getPdfPageCount; local PDF processing writes the overlay on each selected page. Choose all pages or a subset via the page-range check. Opacity, rotation, font size, and a diagonal preset give you the classic corner-to-corner stamp without desktop software. The 50 MB upload cap keeps save operations responsive. Nothing is uploaded to a server. ## How to Add a Watermark to a PDF - Step by Step Most watermarks take under two minutes from upload to download. Text mode is fastest; image mode needs a PNG ready. 1. **Upload your PDF** - Drag and drop or click Choose PDF File. the file checks enforce the 50 MB cap and confirms the file is a PDF before local PDF processing loads. the browser PDF reader reports page count immediately. 2. **Choose text or image watermark** - Text mode: enter custom string, set font size, opacity (10–100%), and rotation or enable Diagonal for -45°. Image mode: upload a PNG logo; the tool scales it to roughly half page width by default. One mode per run - re-upload the output to stack a second layer if needed. 3. **Select all pages or a page range** - All pages stamps uniformly across the document. Page range accepts `2, 4-6` syntax via Page selections are checked against the document. Pages you omit stay unchanged - useful when only appendix sheets need REV B. 4. **Apply and download the watermarked PDF** - Click Apply Watermark, wait for local processing, then Download. Original file on disk stays untouched; you always get a separate output file. ## PDF Watermark Worked Example - Before and After A startup founder exports a 12-page investor deck from Google Slides. Advisors need to review financial projections under NDA, but nothing on the PDF says the deck is confidential or draft. Forwarded slides could be mistaken for final materials posted to a data room. A diagonal CONFIDENTIAL stamp at low opacity solves the labeling problem without blurring charts. ### Before 12-page investor deck PDF with no draft marking; slides could be mistaken for final. ### After Every page shows diagonal CONFIDENTIAL text at 30% opacity. Underlying charts and text remain sharp - vector overlay only. Steps on this page: upload the deck, confirm twelve pages, keep Text mode, enter CONFIDENTIAL, set opacity to 30%, enable Diagonal (-45°), choose All pages, click Apply Watermark, then Download. Partners immediately see draft status while underlying charts and text remain sharp because local PDF processing draws vector text - no screenshot workflow. If only slides 2–11 need marking, switch to Page range and enter `2-11` while leaving the title slide clean for presentation mode. ## When You Need PDF Watermarks - Real-World Use Cases ### 1. Investor deck drafts Founders share pitch PDFs with advisors under NDA before the data room opens. Diagonal CONFIDENTIAL at 25–35% opacity on every slide signals draft status without obscuring metrics. Browser-only processing keeps cap-table details off third-party SaaS upload queues when founders prefer local tools on a personal laptop. ### 2. Legal discovery previews Paralegals export page ranges for opposing counsel review and stamp SAMPLE across exhibits so production copies cannot be filed as final court submissions. Page range `45-90` limits the stamp to exported exhibits while the master brief stays unmarked in the internal share. ### 3. Photography portfolio PDFs Wedding and portrait photographers send proof galleries as PDFs. A PNG logo at 15% opacity discourages uncredited social reposts while still showing image detail. Image mode embeds the logo once per page - file size grows with logo resolution, not with re-encoding the photos underneath. ### 4. Course handouts Professors watermark lecture PDFs with institution name before LMS upload so students know the source and redistribution policy. Center-aligned text at moderate opacity reads on both light and dark slide backgrounds. Pair with headers on [PDF headers & footers](https://www.toolcomb.com/pdf-headers-footers) for chapter titles in the top margin. ### 5. Architectural plan revisions Engineers stamp REV B on revised drawing sheets only via page range 8–14 while cover sheets and unchanged sheets stay clean. Diagonal text at 40% opacity is visible on blue-line backgrounds without hiding dimension strings. Contractors print watermarked sets knowing superseded revisions are obvious in the field. ### 6. HR policy drafts People teams circulate handbook PDFs for manager comment with DRAFT across every page. When policy finalizes, distribute a clean export from the source system - do not rely on watermark removal in Acrobat, which is trivial on simple overlays. Watermarks here are labels, not locks. ### 7. Real-estate listing brochures Agencies overlay a brokerage PNG logo on property PDFs sent to buyers. Low opacity keeps floor plans readable while branding forwarded emails. Compress the watermarked file on [PDF compressor](https://www.toolcomb.com/pdf-compressor) if high-res logos push the attachment past mailbox limits. ### 8. Medical records for second opinion HIPAA-conscious clinics add FOR REVIEW ONLY text before sharing imaging summaries with external specialists. Browser-only processing keeps PHI local - no cloud watermark vendor in the path. Opacity around 35% balances readability of underlying scan text with a clear usage restriction. ### 9. Pre-signing contract drafts Stamp DRAFT or UNSIGNED on every page before circulating for legal review, then sign the final clean export on [PDF sign](https://www.toolcomb.com/pdf-sign) or a certified e-sign platform. Unsigned watermarked copies in email threads cannot be mistaken for executed agreements. ### 10. Archival document copies Families distribute scanned birth certificates and diplomas to relatives with COPY stamped diagonally so notarized originals stay in the safe. COPY does not prevent duplication - it signals which print is the reference copy. Fix sideways scans on [PDF rotate](https://www.toolcomb.com/pdf-rotate) before watermarking if the scanner produced landscape pages. ## Text Watermark vs Image Watermark vs PDF Compressor Pick text for words like CONFIDENTIAL, image for logos, and compressor only when file size - not labeling - is the problem. | Task | Text watermark | Image watermark | PDF compressor | | --- | --- | --- | --- | | Mark draft / confidential | ✓ Text placement | Logo stamps | No | | Brand logo overlay | Text only | ✓ PNG placement | No | | Reduce file size | Minimal impact | Adds image bytes | ✓ re-encode | | Page range support | ✓ Page selection | ✓ Page selection | Whole file | | Opacity and rotation control | ✓ 10–100%, -180° to 180° | ✓ opacity on drawImage | N/A | | Browser-only, 50 MB cap | ✓ local PDF processing | ✓ local PDF processing | ✓ | | Security / DRM | Deterrence only - removable | Deterrence only | No | Text watermarks add the fewest bytes and scale cleanly at any zoom. Image watermarks look professional for logos but increase file size with PNG resolution. Neither replaces encryption or access control. Run compressor after watermarking if email rejects the attachment - compression does not remove the stamp. ## Common PDF Watermark Errors and Honest Limits These are the failures the UI surfaces on purpose, plus jobs this page will not pretend to do. - **Not DRM.** Simple overlays can be removed in desktop editors. Watermarks deter casual misuse; they do not encrypt content or prevent copying. - **Invalid upload.** Non-PDF files and files over 50 MB are rejected before processing starts. - **Empty page range.** Typos like page 99 on a 10-page doc yield zero pages; enter at least one valid index. - **Image mode requires PNG.** JPG logos must be converted to PNG first. SVG and WebP are not accepted in image mode. - **Encrypted PDFs.** local PDF processing cannot load password-locked files without credentials. Unlock locally before uploading. - **Long text may clip.** Very long strings at large font sizes can extend past page edges. Shorten the label or reduce font size. - **One mode per run.** Text and image watermarks are not combined in a single click. Re-upload the output to stack layers. - **Memory on huge files.** Files near 50 MB may spike RAM during pdfDoc.save(). Close other tabs if the browser warns about memory. - **Not redaction.** Watermarks do not remove underlying text. Use proper redaction tools when content must be deleted, not merely labeled. ## Privacy & Security - 100% Browser-Side Watermarking PDF watermarking on this page runs entirely in your browser. local PDF processing and the browser PDF reader load from the same origin as the app; your document bytes are never POSTed to an API, never written to server logs, and never indexed. Suitable for confidential drafts, medical summaries, and legal previews when cloud upload is not permitted. Clear downloads from shared workstations when finished. We do not persist uploads in localStorage. Closing the tab discards in-memory state except any file you explicitly downloaded. No account means no cross-device history. Uploaded PNG logos for image mode are read once into memory and embedded into the PDF - they are not stored on our servers because there are no servers in the processing path. ## Frequently Asked Questions ### What is a PDF watermark? A PDF watermark is semi-transparent text or an image layered on top of each page to mark ownership, confidentiality, or draft status. The overlay sits above existing content without re-rasterizing the page underneath. ### Can I use both text and image watermarks? You choose one mode per run: Text lets you enter a custom string with opacity, font size, rotation, and an optional diagonal preset. Image lets you upload a PNG logo or stamp. Switch modes before processing; the tool does not combine both in a single click, though you can watermark twice by re-uploading the output. ### Does watermarking upload my PDF to a server? No. Watermarking runs entirely in your browser with local PDF processing and the PDF reader loaded on demand. Your PDF bytes never leave your device. There is no account, no cloud queue, and no retention period because nothing is stored remotely. ### Can I watermark only specific pages? Yes. Choose All pages for a uniform stamp, or Page range and enter numbers like 1, 3-5, or 2, 4, 7. Each index is checked against the document page count. Pages you omit stay unchanged. ### What is the maximum PDF file size? Uploads are capped at 50 MB (MAX_PDF_BYTES). That limit keeps local PDF processing save operations responsive in typical desktop browsers. Split oversized archives on the PDF split tool first, watermark the pieces, then merge again if needed. ### How do opacity and rotation work? Opacity is a percentage from 10 to 100 passed to local PDF processing as a decimal. Rotation accepts degrees from -180 to 180. The Diagonal preset sets -45° for classic corner-to-corner CONFIDENTIAL stamps. Text watermarks center on each page; image watermarks scale to half the page width by default. ### Can I watermark password-protected PDFs? Password-protected PDFs must be unlocked before local PDF processing can load them. This page does not include a password prompt. Remove protection locally in a desktop reader, or export an unencrypted copy, then upload it here. ### Will watermarking increase file size? Text watermarks add minimal bytes because they are vector instructions. Image watermarks embed the PNG object, so file size grows with the logo resolution. Neither mode re-compresses existing page images, so underlying photo quality stays intact. ### Does the tool work on mobile browsers? Yes on modern mobile Chrome, Safari, and Firefox, though large PDFs near the 50 MB cap may feel slow on phones with limited RAM. Processing still stays on-device. For heavy documents, a desktop browser is more comfortable. ### Is this PDF watermark tool free? Yes. There is no registration, extra watermark on the output, or daily quota. Watermark as many PDFs as you need as long as each file is under 50 MB and your browser can hold it in memory. ## Related PDF Tools Watermarking is one step in a longer PDF workflow. These sibling tools stay on the same origin: - [PDF sign](https://www.toolcomb.com/pdf-sign) - add a visual signature after watermarking drafts are approved. - [PDF headers & footers](https://www.toolcomb.com/pdf-headers-footers) - margin text alongside center watermarks. - [PDF compressor](https://www.toolcomb.com/pdf-compressor) - shrink watermarked PDFs for email when PNG logos add weight. - [PDF merge](https://www.toolcomb.com/pdf-merge) - combine stamped chapters into one deliverable. - [PDF page numbers](https://www.toolcomb.com/pdf-page-numbers) - add folios alongside confidentiality stamps. - [PDF rotate](https://www.toolcomb.com/pdf-rotate) - fix orientation before stamping sideways scans. - [PDF split](https://www.toolcomb.com/pdf-split) - watermark only the pages you export from a large archive. - [PDF fill form](https://www.toolcomb.com/pdf-fill-form) - complete AcroForm fields on drafts before final watermark removal and sign-off. ## Related Tools Discover more free tools that might help with your next task. [Online PDF Editor Free online PDF editor - merge, split, rotate, watermark, and more in your browser Use Tool](https://www.toolcomb.com/online-pdf-editor) [PDF Compressor Compress PDF files to reduce size Use Tool](https://www.toolcomb.com/pdf-compressor) [PDF Split Split PDF documents into multiple files Use Tool](https://www.toolcomb.com/pdf-split) [PDF Merge Merge multiple PDF files into one document Use Tool](https://www.toolcomb.com/pdf-merge) [PDF Delete Pages Delete specific pages from PDF documents Use Tool](https://www.toolcomb.com/pdf-delete-pages) [PDF Page Numbers Add page numbers to PDF documents Use Tool](https://www.toolcomb.com/pdf-page-numbers) [View All Tools](https://www.toolcomb.com/tools)