Uwarp

Output is always MP4 (H.264 + AAC). First run downloads FFmpeg (~25 MB) once in this browser. Need MOV only? Try /compress-mov.

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Compress video online free

Compress video to 8, 10, 20, or 25 MB in your browser. CRF quality or target size. Local-first, no signup.

What is an online video compressor?

An online video compressor reduces video file size so clips are easier to upload, email, or share. This free video compressor re-encodes to H.264 MP4 with 8/10/20/25 MB target presets or CRF quality, entirely in your browser via FFmpeg WebAssembly — no server upload.

Compress video features

Reduce video size and compress MP4 files privately in the browser.

  • Compress video online

    Upload MP4, MOV, or WebM and download a smaller compressed MP4.

  • Compress MP4 / shrink MP4

    Tune CRF and scale to reduce MP4 file size for sharing limits.

  • Video file size reducer

    See original vs compressed size and savings percent before download.

  • Compress to 8 MB, 10 MB, 20 MB, or 25 MB

    Pick a target size for email, form, and platform upload caps. The encoder retries with a lower bitrate if needed.

  • Quality and scale controls

    Use CRF mode when you want a quality slider, or lower scale to shrink resolution.

  • No server upload

    Compression runs locally — your video never leaves the browser tab.

How to compress a video online

Reduce video size in three steps.

  1. Upload video

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

  2. Pick a target or CRF

    Choose 8 MB, 10 MB, 20 MB, or 25 MB, or switch to CRF quality. Lower scale if you still need more savings.

  3. Compress and download

    Click Compress video, then download the MP4.

Great for

Common compress-video and MP4 shrinker scenarios.

  • Upload size limits

    Hit 8 MB, 10 MB, 20 MB, or 25 MB caps for email, forms, and common upload limits.

  • Faster sharing

    Send a smaller MP4 over chat or cloud storage.

  • Phone and camera clips

    Condense large phone recordings into a lighter MP4.

  • Web embedding

    Prepare a smaller, web-ready MP4 for pages and CMS uploads.

Sources & References

Encoding references for H.264 quality and file-size targets.
  • “Constant Rate Factor (CRF) is the default quality setting for the x264 and x265 encoders.”
    — FFmpeg Wiki — H.264

    FFmpeg H.264 encoding guide: This tool uses CRF in quality mode and bitrate targeting when you pick an 8/10/20/25 MB cap. trac.ffmpeg.org/wiki/Encode/H.264

  • “The MPEG-4 (MP4) container format can contain a number of different types of video and audio.”
    — MDN Web Docs — Media container formats (file types)

    MDN — Media container formats: Output is always an MP4 container with H.264 video and AAC audio for broad playback. developer.mozilla.org/en-US/docs/Web/Media/Guides/Formats/Containers

Frequently Asked Questions

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