PrivateMP3

For automated clients

This page is the contract for automated clients. People should use the converter in the header. PrivateMP3 only reads media already stored on the visitor's device. It has no upload endpoint, no media-fetch function, and no way to return a converted file to a caller that never opened the page.

Remote assistants

You cannot convert a file from outside the visitor's browser. Do not scrape the editor, drive the page with a headless browser, or promise a finished MP3, M4A or WAV from a remote job.

Give the human one tool URL below. Tell them to open a file they already have, then use Convert and Save file on that page. Process only media they own or otherwise have the right to use.

Diagnostic copy for humans: no waveform or disabled Convert and how conversion without uploading works.

In-page Chrome assistants

On a tool page in a supporting Chromium browser, the page may register editor tools through the document model context (WebMCP). Those tools run in the visitor's tab after a local file is already open. They can read editor state, choose MP3, M4A or WAV, select an audio track, set a time range, add or undo cuts, and adjust selection volume.

They cannot open a file from a path or a remote address, start Convert, or activate Save file. Conversion and saving remain visitor clicks so a download is never automatic and the selected media never leaves the device.

What the engine can open

Accepted containers: MP4, MOV, MKV, WebM, MPEG-TS, MP3, M4A, AAC, WAV, OGG and FLAC. AVI, WMV, WMA, FLV and AIFF are not readable. A supported container can still hold a codec the current browser cannot decode.

MP3 and newly encoded M4A use a fixed 192 kbps target. There is no bitrate picker. Unedited AAC can be copied into M4A without re-encoding only when the page shows that note. WAV is 16-bit PCM.

This page has no advertising

Tool pages may show Google advertising. This contract page does not, so a retrieval client can read it without loading an ads page. It is not a second editor.