Audio & video / Local FFmpeg tool

Audio to FLAC Converter

Create a lossless FLAC copy with a selectable compression level without sending audio away.

● Files stay in your browser
Files stay in your browser

The first run loads an approximately 31 MB FFmpeg WebAssembly core from this site. It does not use a CDN or upload your files.

Files are limited to 200 MB total and 20 minutes; mobile devices use an 80 MB limit. Reverse, GIF and boomerang tools have lower duration caps.

Choose files, set the controls, then start.Progress: 0%

Processed result

The first run loads an approximately 31 MB FFmpeg WebAssembly core from this site. It does not use a CDN or upload your files.

Validated downloads will appear here after processing.

Local AI / Speech to text

Transcribe the current audio or video

Open-source Whisper Tiny runs in your browser. The file, audio and result are never uploaded.

◎ First use loads about 64 MB of model and runtime files

Choose an audio or video file in the workbench above first.

◎ The model loads only from 321Kit; MiniMax is not called and no transcript history is stored.

Transformers.js + Whisper Tiny (Apache-2.0)

Transcript

How it works

Audio to FLAC Converter

FLAC compression levels change encoding effort and file size, not decoded sound quality.

How does this tool process my file?

FLAC compression levels change encoding effort and file size, not decoded sound quality. Processing uses single-thread FFmpeg.wasm. The page does not upload, store or inspect file content outside this device. Cancel, error and page close terminate the worker and revoke temporary object URLs.

What limits apply to the output?

Converting a lossy source to FLAC cannot restore detail already discarded. Files are limited to 200 MB total and 20 minutes; mobile devices use an 80 MB limit. Reverse, GIF and boomerang tools have lower duration caps.

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