Your Audible library,
converted on your device.
Sign in, load your library, and save the titles you own as plain M4B files. The browser does the conversion; Cloudflare only handles the small auth/API calls and the CDN byte relay needed for CORS.
- 01Trimmed converterA 765 KiB ffmpeg.wasm build handles the AAX/AAXC stream copy in your browser.
- 02Browser-held identityYour Audible device keys stay in local browser storage and are only used to sign your own requests.
- 03M4B outputThe saved file keeps audiobook chapters and works with standard audiobook players.
How it works
- Renders this page, stores your Audible identity in
localStorage, and signs requests with the ADP token Amazon issued to your device registration. - Runs a custom
ffmpeg.wasmcore (no decoders or encoders — just themovdemuxer with Audible'saudible_key/audible_ivpath and themp4/ipodmuxers). - Streams the encrypted source from Audible's CloudFront, decrypts it in WebAssembly, and writes the M4B to your file system with
showSaveFilePicker.
functions/auth/loginopens an Amazon OAuth flow with a PKCE challenge and swaps the returned code for ADP tokens by hittingapi.amazon.<tld>/auth/registeron your behalf.functions/libraryandfunctions/license/[asin]are thin pass-throughs toapi.audible.<tld>, signing each request with the private key your browser holds and forwarding the response back unchanged.functions/sourceis a byte proxy for Audible's CloudFront audio (so the browser can read the file despite the CDN's CORS policy). It does not store, decrypt, or transcode anything — just relays bytes with aRangeheader.
- No database, no KV, no R2. Cloudflare has nothing about you between requests.
- No analytics, no tracking pixels. The only outbound calls are to Audible / Amazon, Amazon's image CDN for cover art, and the GitHub / Buy Me a Coffee embeds.
- No DRM bypass for content you do not own. The flow only converts books already in the signed-in Audible account, using the licence data Amazon returns to the registered device.
Source on GitHub — the Pages Functions and ffmpeg build script are there to inspect.
Connect Audible
Start with Amazon's Audible sign-in. Your credentials stay on Amazon's page; this app only receives the final authorisation URL needed to finish the device login.
Amazon hands the authorisation code back to a page on its own domain. Copy that URL when you see "Page Not Found" — that's the signal we're done.
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Pop-up opened
Amazon's sign-in is in a new window. If the pop-up was blocked, hit Re-open.
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Sign in on Amazon
Use the same credentials as the Audible mobile app. Two-factor codes work as normal.
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Copy the URL
Amazon lands you on a "Page Not Found" page on audible.co.uk. That is the page you want — copy the full address from the bar.
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Finish here
Back in this tab, hit Finish sign-in. We read the URL from your clipboard and finalise the handshake.
Clipboard didn't work? Paste the URL yourself.
Your library
Conversion
No WASM run yet.