Uwarp

Output is MP4 (H.264 + AAC when audio is kept). First run downloads FFmpeg (~25 MB) once in this browser.

Help Us Improve

—

(—)

MP4 speed up online free

MP4 speed up or slow down from 0.25× to 4× in your browser. Free video speed changer. Local-first. No signup.

What is a video speed changer?

A video speed changer lets you speed up video or slow down a video for fast playback, slow motion, or time-lapse style clips. This free speed up video online tool also works as a slow-down / accelerate editor — all in your browser with FFmpeg WebAssembly, no server upload.

Video speed changer features

MP4 speed up or slow down online with adjustable playback rate.

  • MP4 speed up

    Accelerate an MP4 up to 4× for quicker reviews or hyperlapse-style shares.

  • Slow down video

    Drop to 0.25×–0.75× for slow motion without installing desktop software.

  • Change video speed

    Use presets or a fine slider to set the exact playback rate you need.

  • Keep or mute audio

    Retimed audio follows the new tempo, or mute when you only need picture.

  • Local-first

    Processing stays on your device with FFmpeg WebAssembly.

How to speed up a video

Speed up or slow down a video online in three steps.

  1. Upload video

    Drop an MP4, MOV, or WebM file (up to 200 MB).

  2. Pick a speed

    Choose a preset or slider value above 1× (faster) or below 1× (slower).

  3. Export MP4

    Click Speed up / Slow down video, then download.

Great for

Common speed-up and slow-motion scenarios.

  • Faster reviews

    Speed through long recordings, lectures, or meeting captures.

  • Slow motion moments

    Slow down sports, dance, or product demos for emphasis.

  • Social clips

    Make punchy sped-up intros or dreamy slow-mo outros.

  • Editing prep

    Create a time-scaled take before cutting it into a longer edit.

Frequently Asked Questions

Quick answers about this tool—open a question to read more.