Change video & audio speed
Speed up lectures, slow down tutorials, make slow motion — without the chipmunk effect. Runs entirely in your browser.
Free · No signup · Files never leave your device
Drag and drop a video or audio file
or click to browse
How it works
Drop your file
Any video or audio file — it stays on your device.
Pick a speed
From 0.25× slow motion to 4× fast — audio is time-stretched so voices keep their natural pitch.
Download the result
Preview the new speed and download for free — no watermark.
Faster without sounding wrong
Naively speeding up a recording raises its pitch — the classic chipmunk voice. This tool time-stretches the audio instead: the waveform is resynthesized at the new tempo while the pitch stays exactly where it was, the same processing podcast and audiobook apps use for their 1.5× and 2× buttons. The video track is re-timed to match, so picture and sound stay perfectly in sync at any speed from 0.25× to 4×.
What people use it for
Speeding up recorded lectures, webinars, and meetings to get through them in half the time — 2× turns an hour-long recording into thirty minutes you can actually sit through. Slowing down tutorials, dance choreography, golf swings, and language clips to catch details at 0.5× or 0.75×. Creators use modest speed-ups (1.1–1.25×) to tighten pacing before publishing, and slow motion for emphasis. Because the result is a real file, the new speed works everywhere — no player-side speed setting needed.
Audio is fast; video takes a moment
Audio files (MP3, WAV, M4A...) only re-encode the audio stream and finish quickly even for long recordings. Videos must be fully re-encoded to rewrite the frame timing, which runs at roughly real-time speed in the browser — fine for typical clips, noticeable for hour-long files. If you only need part of a long video, trim it first and change the speed of the section you keep.
Frequently asked questions
No. The audio is time-stretched, not resampled — speech gets faster or slower but keeps its natural pitch, the same technique podcast apps use for their speed controls.
Changing speed rewrites every frame timestamp, so the video must be re-encoded — and that runs entirely in your browser. Audio-only files skip the video encode and finish much faster. Expect roughly real-time processing for typical videos.
Anything from 0.25× (quarter speed slow motion) to 4× (quadruple speed), in steps of 0.05. The common presets — 0.5×, 0.75×, 1.25×, 1.5×, 2× — are one click.
No — frames are shown longer rather than interpolated, so 0.5× halves the effective frame rate. For footage shot at 60 fps that still looks perfectly smooth; for 24–30 fps sources, strong slow-mo will look steppier than camera-native slow motion.
Yes. The speed changer is completely free, with no signup, watermarks, or limits. We make money from our video translation service, not from this tool.
No. All processing happens locally in your browser using WebAssembly. Your file never leaves your device — you can even disconnect from the internet once the page has loaded.