Fifteen rules · EPUB Accessibility 1.1 · WCAG 2.x · SARIF 2.1.0

Audit an EPUB and get a repaired book back.

booklens audits an EPUB against EPUB Accessibility 1.1 and WCAG 2.x, then writes a repaired EPUB. It runs offline, exits with a CI-friendly status code, and can be scripted.

Open the playground View source on GitHub
curl -fsSL https://raw.githubusercontent.com/srivtx/booklens/main/install.sh | sh

Installs the booklens binary with Bun. It is not published to npm; bunx github:srivtx/booklens#main runs it without installing.

booklens audit fixtures/inaccessible.epub 
$ booklens audit fixtures/inaccessible.epuberror E008 OEBPS/chapter1.xhtml 1 image(s) missing an alt attribute.error E009 OEBPS/chapter1.xhtml html element is missing both lang and xml:lang attributes.warning W012 OEBPS/chapter1.xhtml Headings skip a level or do not begin with an h1.warning W013 OEBPS/chapter1.xhtml Table has no header cells (no <th> or role="columnheader").warning W014 OEBPS/chapter1.xhtml Link text is a raw URL: https://example.comerror E001 OEBPS/content.opf Publication is missing a dc:language declaration.error E003 OEBPS/content.opf Publication is missing schema:accessMode metadata.warning W010 OEBPS/nav.xhtml Navigation document is missing a landmarks nav element.info W011 OEBPS/nav.xhtml Navigation document has no page-list; the publication contains no pagebreaks.…inaccessible.epub: 10 error(s), 8 warning(s), 1 info

What it catches

The failures that make a book unreadable to assistive technology, and what fix does about each one.

A book with no language or title
An EPUB needs a declared language and title. When they are missing, booklens reports it (E001, E002) and fix writes them from the CLI options.
Missing accessibility metadata
The schema:* properties say how the book can be used. booklens flags the gaps (E003–E006, W007) and fix adds them.
Images with no alt text
An image without an alt attribute is silent to a screen reader. booklens reports it (E008) and fix writes a logged alt="TODO: describe image" placeholder.
Pages with no language
If an XHTML document has neither lang nor xml:lang, assistive technology cannot choose the right pronunciation. E009, and fix sets both.
Navigation that is incomplete
Missing landmarks, a page-list, or a whole navigation document (W010, W011, E015) makes a book hard to move through. fix writes them and updates the manifest.
Structure that needs a human
Skipped headings, tables without headers, and raw-URL link text (W012–W014) are reported but never guessed at, because a wrong repair corrupts the book.

Quick start

Install once, then point it at a book. audit reports; fix writes a repaired EPUB.

quick start 
# install the binary$ curl -fsSL https://raw.githubusercontent.com/srivtx/booklens/main/install.sh | sh# audit a book$ booklens audit book.epub# write a repaired EPUB$ booklens fix book.epub -o book.fixed.epub

Full flags, exit codes, and the TypeScript API are in Usage.

Playground

Drop a real .epub below, or audit the sample book. Everything runs in your browser; nothing is uploaded.

Runs entirely in your browser. Nothing is uploaded.

Choose or drop an .epub file

Drag a book onto this box. It never leaves this tab.

No EPUB audited yet.

Documentation

The landing page is the pitch. The details live on four short pages.

Rules
The fifteen checks, how a book is audited, and what fix changes.
Usage
Install, every CLI flag, the exit-code scheme, JSON output, and the library API.
CI
SARIF 2.1.0 and GitHub code scanning, with a workflow you can paste.
FAQ
Scope, limitations, and how booklens compares to ACE, EPUBCheck, and Access-Aide.