Edit EPUB metadata
Rewrite the OPF title, creator, language, identifier, publisher, date and description of an EPUB and repack it, copying every other archive entry as raw compressed bytes. Processing runs in Rust-compiled WebAssembly and the file never leaves your browser.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
EPUB base64
New EPUB
The output is the base64 of the edited EPUB.
Loading the ebook module…
Paste the EPUB base64 and fill in the fields to change
Rewritten entries: 0 · Untouched entries: 0
What this tool does
- Normalise author and publisher across a series.
- Add a language or identifier to a self-made EPUB.
- Rename a title and export the EPUB again.
Example
Input
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
Output
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
Only the OPF is rewritten; every other entry (chapters, styles, images) keeps its original compressed bytes. Empty fields stay untouched.
Frequently asked questions
Is the body recompressed?
No. Entries other than the OPF are copied as raw compressed data, keeping CRC and content.
What about empty fields?
Empty means unchanged; only explicitly filled fields are written to the OPF.
Can I add a field that was missing?
Yes, new elements are inserted before </metadata>.
Can encrypted EPUBs be edited?
No, an encrypted entry makes the tool fail with unsupported.
Keywords：epub修改元数据电子书epub editoffline