Change audio speed from 0.25× to 4× with pitch-preserving tempo or tape-style varispeed, target-duration matching, real-time preview, trim, loudness, fades, WAV/MP3/OGG export, metadata and verified output — completely free.
Two speed enginesPreserve pitch for speech/music, or use analog-style varispeed.
Match a target timeEnter a desired duration and calculate the exact speed automatically.
Export your wayLossless WAV, compact MP3 or OGG Vorbis with verification.
Time-lab queue0 / 8
1.00×
Add audio to begin.
High-quality export uses pinned FFmpeg/WebAssembly locally. Preview uses the browser audio engine instantly; no account or audio upload is required.
Timing waveformOriginal source · local decode
Time impactSelect audio to see the exact new duration and pitch effect.