Read EPUB metadata
Read an EPUB OPF metadata (title, creator, language, identifier, publisher, date, description) plus spine and manifest statistics, listing missing fields explicitly. Parsing runs in Rust-compiled WebAssembly and the book never leaves your browser.
Runs in your browserEvery computation happens in your browser — your data never leaves this device.
Metadata
Missing fields show (missing) and are listed in missing.
Loading the ebook module…
Paste the EPUB base64 to read its metadata
Filled fields: 0 · Spine documents: 0
What this tool does
- Check title and creator before organising a library.
- Confirm every spine document really exists.
- Verify language and identifier fields.
Example
Input
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
Output
dc:title = Snow dc:creator = Ada dc:language = en dc:identifier = urn:uuid:uk-ebook dc:publisher = (missing) dc:date = (missing) dc:description = (missing) spine = 2 document(s) manifest = 3 item(s)
The input is the base64 text of an EPUB; the spine preview length only trims the listed spine while spineCount stays complete.
Frequently asked questions
Is my book uploaded?
No. The page reads and encodes the file locally and parsing runs in browser WebAssembly.
What about missing fields?
They come back as null and are listed in stats.missing in a fixed order.
Are KF8 or PDF files supported?
No. Only the EPUB OCF container and OPF are accepted; anything else fails with invalid-epub.
Are covers or images unpacked?
No. Only metadata and the spine list are read.
Keywords：epub元数据电子书opfepub metadataoffline