Is this audio speed changer really free?

Yes. There's no signup, no watermark, and no limit on how many files you process — everything runs in your browser.

Does my audio get uploaded to a server?

No. Speed changes happen entirely locally using FFmpeg and the Web Audio API, both running in your browser. Your file never leaves your device.

What audio formats can I upload?

MP3, WAV, M4A, OGG, FLAC, AAC, Opus, and WebM are supported, up to 100MB per file.

What's the difference between keeping pitch and the tape effect?

Keep-pitch mode changes tempo only — a voice stays at its natural pitch whether you slow it to 0.25x or speed it to 4x, using FFmpeg's atempo filter. The tape effect changes pitch and speed together, exactly like adjusting a physical tape or record's playback speed: faster means higher-pitched (the classic "chipmunk" or nightcore sound), slower means a deep, dragging pitch.

Can I remove pitch shift after using the tape effect?

Not from the tape-effect output itself — pitch and speed are linked together in that mode by design. If you need the original pitch back, reprocess the original file using keep-pitch mode instead.

Does speeding up audio lose quality?

Keep-pitch mode processes audio losslessly internally and can export as lossless WAV with no quality loss. Choosing MP3 output applies standard MP3 compression, similar to any MP3 encoder. The tape effect is a pure playback-rate change and doesn't degrade audio quality either — the output format you choose is what determines final quality.