1. [Home](https://www.toolcomb.com/) 2. [Converter Tools](https://www.toolcomb.com/converter-tools) 3. EPUB Metadata Editor # EPUB Metadata Editor - Free Online Title & Author Editor Edit an EPUB book's title, author, language and identifier in your browser. Download a revised EPUB and check its metadata in your reading app. ### Open EPUB Drop .epub or click to browse local ZIP processing · container.xml → content.opf · private ### Dublin Core fields dc:title dc:creator dc:language _en_ dc:identifier Download EPUB Clear ## What is an online EPUB metadata editor? An EPUB metadata editor lets you update a book's title, author, language and identifier without changing its chapters. Open an EPUB, review the fields, and download a revised copy. The editor finds the package document using the book's container information. If a book appears under an old title or an unknown author in your reader, correcting its metadata may help. For example, change a draft title to the final title, download the revised book, and re-import it into your reading app. Some apps cache the previous listing. Editing happens in your browser; the book is not uploaded for processing. Keep an original copy and check the downloaded EPUB in the reading systems you use, especially before distribution. EPUB 2 and EPUB 3 both rely on the container.xml indirection so the OPF can live in a subfolder. Hard-coding “content.opf” at the archive root would break many valid books. Following the rootfile path is the correct, interoperable approach and is what this editor implements. Identifier fields may hold UUIDs, ISBNs, or store-specific IDs. Changing them can help deduplicate libraries but may confuse apps that keyed bookmarks on the old id - update thoughtfully. Language tags should follow BCP 47 (en, fr-CA, de) so hyphenation and voiceover engines pick the right defaults. This tool is intentionally not a full ebook studio. You will not reflow chapters, embed fonts, or rebuild a navigation document here. Pair with Calibre or Sigil when you need structural edits, and use ToolComb when the only problem is a wrong shelf title or missing author string. After download, validate in more than one reader when the book matters commercially. Apple Books, Thorium, KOReader, and Calibre’s viewer each surface metadata slightly differently. If a store-synced Kindle entry ignores sideload OPF, that is a platform limitation, not a failed ZIP write. Performance depends on archive size because local ZIP processing must rewrite the package. Text-heavy novels are snappy; image-heavy fixed-layout EPUBs take longer and use more RAM. The soft ceiling around 100 MB keeps typical novels and docs comfortable in a tab. Educators can use the editor to stamp class codes into titles (for example “Physics 101 - Week 3 Reader”) so student libraries sort cleanly. Archivists can normalize creator strings to “Last, First” conventions before ingesting into a catalog - still verify catalog rules separately. In short: use the free EPUB metadata editor for private Dublin Core fixes via container.xml → OPF; escalate to desktop ebook labs for spine, encryption, and advanced packaging work. From a packaging standards view, the OPF metadata section is the contract between your file and reading systems. When dc:title is empty, many UIs fall back to the ZIP filename, which is why exports named build_output.epub look unprofessional on a shelf. Spending thirty seconds fixing title and creator here often improves perceived quality more than tweaking CSS inside chapters. Identifiers deserve special care in library science contexts. If two EPUBs share the same dc:identifier, some apps treat them as the same book and overwrite progress or annotations. Generating or correcting a unique identifier before wide distribution prevents that class of support ticket. Conversely, do not casually change identifiers on a book readers already annotated unless you accept progress resets. Language metadata influences more than labels. Screen readers, dictionary lookup, and hyphenation engines consult language tags. A French novel Markdown parser as en will mispronounce words in TTS modes. Setting dc:language correctly is a small edit with outsized accessibility impact, especially for learners using read-aloud features. Self-publishers moving between draft and final titles can keep the same EPUB body while updating metadata for beta readers versus store submission. That avoids regenerating the entire pipeline from InDesign or Scrivener solely to rename the shelf entry. Always keep the store’s required metadata fields in sync with what you patch locally so audits do not flag mismatches. Because local ZIP processing rewrites the archive, optional EPUB features like fonts and media overlays remain byte-stable as long as you do not touch those paths. If a particular reader rejects the output, compare unzip listings before and after to confirm only the OPF changed - a useful debugging habit when validating commercial deliveries. ## How to edit EPUB title and author in your browser Six steps from dropzone to a re-zipped EPUB. Keep an original backup when the book is irreplaceable. 1. **Open the EPUB metadata editor** Load this page in a modern browser. local ZIP processing unpacks the EPUB (a ZIP archive) entirely in your tab - book bytes are not uploaded to ToolComb. 2. **Upload an .epub file** Drag an EPUB onto the dashed dropzone or click to browse. Standard EPUB 2/3 packages with META-INF/container.xml pointing at a content.opf work best. 3. **Wait for Dublin Core fields** The tool reads container.xml, locates the OPF package document, and fills dc:title, dc:creator, dc:language, and dc:identifier when present. 4. **Edit title, author, language, identifier** Update the form fields. Language should be a BCP 47 tag such as en or en-US. Identifier is often a UUID or ISBN-style string already in the file. 5. **Download the new EPUB** Click Download EPUB to rebuild the ZIP with the patched OPF and save a file named with a _toolcomb suffix. Open it in your reader to confirm the library listing. 6. **Clear before the next book** Use Clear to drop the in-memory ZIP. Keep originals when you need an untouched archival copy. ## Before and after: sideloaded novel library ### Before A reader dumped twenty fan-converted EPUBs onto a Kobo. Half showed blank authors and filenames like “chapter_export_final2”. Finding books in the device UI was painful, and Calibre was not installed on the travel laptop. ### After Each file was opened in this EPUB metadata editor, given a proper dc:title and dc:creator, then re-downloaded. After re-import, the Kobo library sorted by author. Chapter content was untouched; only the OPF metadata changed. Batch heavy collections in Calibre later. Use ToolComb for the handful of broken files you notice on the go. Always keep the pre-edit EPUB when DRM-free archives are your only copy. ## When EPUB metadata editing helps ### 1. Fix Unknown titles on ereaders Populate dc:title so shelves show human names instead of export filenames. ### 2. Self-publishing QA before upload Confirm author and language tags match the store listing before you submit. ### 3. Course pack labeling Teachers stamp term and week into titles for student device libraries. ### 4. Archive ingest normalization Align creator strings before importing donations into a catalog. ### 5. Translation language tags Set dc:language correctly so TTS and hyphenation behave. ### 6. ISBN / UUID cleanup Correct identifiers that collide when two exports share a default UUID. ### 7. Travel laptop fixes without Calibre Browser-only editing when you cannot install desktop software. ### 8. Client manuscript previews Authors rename working titles before sending review EPUBs to editors. ### 9. Comic and fixed-layout labels Update series titles without opening a full comic tooling chain. ### 10. Privacy-sensitive unpublished drafts Adjust metadata locally so drafts never upload to a conversion SaaS. ### 11. Series prefix standardization Add consistent “Series Name - Book N” title prefixes so device libraries group related volumes. ### 12. Accessibility language corrections Fix wrong dc:language tags that break TTS pronunciation for multilingual catalogs. ## EPUB metadata tooling compared Choose based on batch needs, structural editing, and privacy. | Option | Scope | Privacy | Best for | | --- | --- | --- | --- | | ToolComb EPUB Metadata Editor | DC title/creator/lang/id | Local local ZIP processing | Quick OPF fixes | | Calibre | Full library + convert | Local | Batch and formats | | Sigil | Full EPUB XML | Local | Structural editing | | Store dashboards | Retail metadata | Vendor cloud | Published titles | | Manual unzip + text edit | Anything | Local | Experts debugging OPF | Use ToolComb for private, zero-install Dublin Core edits. Use Calibre or Sigil when you must rebuild spines, fix TOC, or convert formats at scale. A practical pattern is to fix obvious Unknown titles here on the day you notice them, then schedule a Calibre library pass monthly for bulk cleanup, duplicates, and format conversions you deliberately postponed. ## Limits and tips - Edits target dc:title, dc:creator, dc:language, and dc:identifier - not full OPF schemas. - Encrypted/DRM EPUBs that cannot unzip will not load; no circumvention is provided. - The form edits the first creator; additional creator elements are left in place. - Soft size guidance ~100 MB. - Some readers cache old metadata until you remove/re-add the book. - Does not modify chapter HTML, CSS, or images. - Keep backups of archival copies before rewriting. - Validate commercially important files in your target reading app after download. ## Privacy for ebooks EPUB bytes stay in your browser memory via local ZIP processing. ToolComb does not host your library on this page. Downloaded EPUBs land in Downloads - clear them on shared machines after reviewing unpublished manuscripts. Metadata can itself be sensitive (working titles, client names); local editing reduces third-party exposure. When sharing edited EPUBs with collaborators, rename downloads so filenames match the new dc:title; otherwise chats and cloud drives keep advertising the old export name beside corrected shelf metadata. ## Frequently Asked Questions ### What is EPUB metadata? EPUB metadata is descriptive information stored mainly in the package document (content.opf), often using Dublin Core elements such as title, creator (author), language, and identifier. Reading apps use these fields for library shelves, sorting, and search. ### How does this editor find content.opf? It opens the EPUB with local ZIP processing, reads META-INF/container.xml, and follows the rootfile full-path attribute to the OPF. That is the standard EPUB container mechanism. ### Does editing upload my ebook? No. Unzip, XML edits, and re-zip all happen in the browser. Watch the Network panel - there is no book upload API call. ### Will chapter HTML change? The editor changes the package metadata document, not the chapter files. Keep the original EPUB and check the downloaded copy in your reading app; the archive and package XML are rewritten. ### Can I fix a missing title that shows as Unknown? Yes. Many sideloaded EPUBs lack a proper dc:title. Set the title here, download, and re-import into Apple Books, Calibre, KOReader, or Kindle sideload tools that honor OPF metadata. ### What about multiple authors? The form edits the first creator element and leaves other creator elements in place. For multiple authors, roles or complex contributor metadata, use a full EPUB editor and verify the result in your reader. ### Is DRM-stripped EPUB supported? If the file is a normal ZIP-based EPUB you can open, metadata editing works. Encrypted/DRM-locked books that cannot be unzipped will fail to load - we do not provide DRM circumvention. ### Is there a file size limit? About 100 MB. Huge comic EPUBs with many images may stress memory while local ZIP processing rebuilds the archive. Prefer desktop Calibre for very large manga archives. ### Why did my reader ignore the new title? Some apps cache library metadata or prefer Amazon/store databases over sideloaded OPF. Remove and re-add the book, or check whether a secondary metadata file overrides OPF on that platform. ### Is the EPUB metadata editor free? Yes - no account or watermark inside the book. Filename suffixes mark ToolComb exports in your Downloads folder. ### Does this create a new EPUB version number? It rewrites the OPF metadata and rebuilds the ZIP. It does not automatically bump package version attributes unless they already exist and you change them elsewhere. Treat the download as a new file revision in your own naming scheme. ### Can I edit the cover image? Not in this tool. Cover images live as separate manifest items. Use an image editor plus a full EPUB lab if you need to replace covers; here we only patch Dublin Core text fields. ## Related converter and document tools - [PDF Edit](https://www.toolcomb.com/pdf-edit) - Adjust PDF content when your manuscript is PDF-first. - [Image to PDF](https://www.toolcomb.com/image-to-pdf) - Bundle page scans before ebook pipelines. - [Metadata Remover](https://www.toolcomb.com/metadata-remover) - Strip extras from images you embed. - [Word Counter](https://www.toolcomb.com/word-counter) - Check manuscript length in plain text. - [Diff Checker](https://www.toolcomb.com/diff-checker) - Compare text revisions beside ebook exports. - [YAML to JSON](https://www.toolcomb.com/yaml-to-json) - Convert related config for publishing scripts. ## Related Tools Discover more free tools that might help with your next task. [XML to JSON Convert XML data to JSON format Use Tool](https://www.toolcomb.com/xml-to-json) [CSV to JSON Convert CSV data to JSON format Use Tool](https://www.toolcomb.com/csv-to-json) [YAML to JSON Convert YAML data to JSON format Use Tool](https://www.toolcomb.com/yaml-to-json) [JSON to CSV Convert an array of JSON objects into CSV rows Use Tool](https://www.toolcomb.com/json-to-csv) [Array to Image Convert array data to visual image representation Use Tool](https://www.toolcomb.com/array-to-image) [Bitmap to Array Convert bitmap images to array data Use Tool](https://www.toolcomb.com/bitmap-to-array) ### Related guides Read the how-to, then come back to this tool when you are ready to run it locally. - [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.](https://www.toolcomb.com/blog/zip-inspector-and-epub-metadata-basics) - [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.](https://www.toolcomb.com/blog/best-free-csv-chart-and-file-inspector-tools) [View All Tools](https://www.toolcomb.com/tools)