w3c/epubcheck
The conformance checker for EPUB publications observed · 2026-08-28
Health v2 · maintenance only
59/100
- Activity 70
- Release rhythm 21
- Longevity 100
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-03. Adoption (stars, forks) is never an input.
- gap_med: 122.0
- age_days: 4706
- days_rel: 366
- days_push: 185
- n_releases_24m: 3
Adoption not part of the score
1952 stars · 442 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
EPUBCheck is the official W3C conformance checker for EPUB publications, validating EPUB 2 and EPUB 3 files against the official specifications. It is distributed as a standalone command-line tool and as a Java library for integration into larger publishing systems.
Use cases
- validate an epub file before submitting it to a retailer
- check epub3 conformance against the official specification
- integrate epub validation into a publishing pipeline
- find errors in an ebook's package metadata and content markup
- batch-check a folder of epub files for defects
- verify internal references and container structure of an epub
When to choose
- you need the authoritative, spec-compliant EPUB validator used by the publishing industry
- you want a command-line tool or Java library for automated EPUB validation
- you are a content distributor gating ebook acceptance on conformance checks
When to avoid
- you need a graphical interface and don't want to use third-party GUI wrappers
- you need editorial review like typo or content-quality checking, which EPUBCheck does not do
- you are validating non-EPUB ebook formats such as MOBI or PDF
Facets
cli-tool · maturity stable
testing parser developer-tools files developer-tools documentation cross-platform cli jvm epub epub3 epub2 validation conformance-checker digital-publishing w3c java-library publishing
10 sources
- readme: https://github.com/w3c/epubcheck · fetched 2026-08-28 · 40eede6cf4d4
- homepage: https://www.w3.org/publishing/epubcheck/ · fetched 2026-08-29 · 9b1e550a45da
- site_page: https://www.w3.org/publishing/epubcheck/about · fetched 2026-08-29 · 34036ecaa404
- site_page: https://www.w3.org/publishing/epubcheck/docs · fetched 2026-08-29 · cc7fd51fb822
- site_page: https://www.w3.org/publishing/epubcheck/docs/support · fetched 2026-08-29 · 5f946d9a4754
- site_page: https://www.w3.org/publishing/epubcheck/docs/getting-started · fetched 2026-08-29 · 4d3596f88947
- site_page: https://www.w3.org/publishing/epubcheck/docs/translating · fetched 2026-08-29 · 80c74c2352ca
- site_page: https://www.w3.org/publishing/epubcheck/docs/apps-and-tools · fetched 2026-08-29 · 299e882925d6
- site_page: https://www.w3.org/publishing/epubcheck/about/sponsors · fetched 2026-08-29 · f5da62b4b033
- site_page: https://www.w3.org/publishing/epubcheck/releases · fetched 2026-08-29 · 02db097a04b7
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| w3c/epubcheck | main | 59 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem