Compress video
Make MP4, MOV, WebM and MKV videos smaller by quality level, target file size or bitrate, with an optional resolution limit. Encodes H.264 (MP4), VP9 (WebM) or AV1 (MP4) with the browser’s own encoder.
Process locally
Files stay in this browser session. Closing or clearing releases them.
Choose files
MP4, MOV, WebM, MKV, up to 5
Drop files here, or
Adjust settings
Optional: Video codec, Quality, Target size and more
Run
Processes in this browser; cancel at any time
Common tasks
About this tool
Compress videos in your browser without uploading them: MP4, MOV, WebM and MKV in, a smaller MP4 or WebM out. Choose a quality level, a target file size such as 25 MB for email, or a video bitrate, and optionally a largest resolution such as 720p.
With a target size, the tool works out the bitrate from the video’s length and scales the picture down when the target is too small for full resolution, so the result fits. H.264 MP4 plays everywhere, VP9 WebM is smaller for the same quality, and AV1 is smaller still but slowest to encode. Each file’s new size is shown next to it, and a report lists what was done.
How to use it
- Choose or drop up to 5 videos, 80 MB in total.
- Keep “Video codec” on H.264 MP4 unless you know the other side plays WebM or AV1.
- For a file size limit, enter it under “Target size” in MB, such as 25 for email. Otherwise pick a “Quality”, or a fixed “Video bitrate”.
- Optionally set a “Largest resolution”, such as 720p, or remove the sound.
- Select Run, compare the sizes and download the compressed videos.
Formats and limits
- Input
- MP4, MOV, WebM, MKV, up to 5 files
- Output
- MP4, WebM
- Size limit
- 80 MB per file
- Settings
- Video codec (H.264 MP4, VP9 WebM, AV1 MP4); Quality (High: light compression, Medium: recommended, Low: smallest file); Target size; Video bitrate (From the quality, 500 kbps, 1 Mbps, 2 Mbps, 3 Mbps, 5 Mbps, 8 Mbps); Largest resolution (Keep, 1080p, 720p, 480p, 360p); Sound (Keep, Remove)
- Privacy
- Files stay in the current browser session. No file bytes are uploaded.
- Price
- Free, no sign-up
Common questions
How do I compress a video to a specific size?
Enter the size under “Target size”, for example 25 MB. The tool aims a little below it, scales a long or high-resolution video down until low quality still fits, and drops 60 fps to 30. If the first try comes out too big it tries once more with a lower bitrate, and the report says whether the target was met.
Why did I get my original video back?
When the video is already in the chosen format, say an H.264 MP4, and is either under the target or would not get any smaller, the tool returns the original rather than a re-encoded copy that looks worse. The report shows ALREADY_SMALL or NOT_SMALLER for that file.
Which codec should I choose?
H.264 MP4 opens on any phone, computer, TV and website. VP9 WebM is about a third smaller at the same quality and plays in browsers, Android and Discord. AV1 MP4 is smaller again but needs a recent device to play and takes the longest to encode.
What if my browser cannot encode the codec?
The tool stops with a message that names the missing encoder and the ones your browser has, so you can choose another. Current Chrome and Firefox encode H.264, VP9 and AV1 on most computers; a browser without WebCodecs cannot compress videos here.
Why does a long video fail partway?
Each run may take at most 2 minutes, and every frame has to be decoded and encoded again. Choose a lower “Largest resolution”, H.264 instead of AV1, or compress one video at a time; trimming the video first also helps.
Related tools
Convert video format
Convert between MP4, WebM, MKV and MOV; MP4 and MOV get H.264 video and AAC sound so any player opens them, and other formats copy streams when they can. Scale down, remove the sound or trim at the same time. Encoding uses the browser.
Extract audio from video (MP4 to MP3)
Take the sound out of MP4, MOV, MKV or WebM video and convert it to MP3, M4A, OGG, WebM or WAV, or keep the track unchanged in its own container, optionally trimmed. Files are not uploaded.
Remove audio from video
Mute MP4, MOV, WebM and MKV videos by removing the audio track. The picture is copied without re-encoding, so its quality, resolution and rotation stay exactly the same.
Resize video
Change the resolution of MP4, MOV, WebM and MKV videos, for example to 1080p or 720p, and optionally make them square (1:1), vertical (9:16), widescreen (16:9) or 4:5 by cropping or adding black bars. The sound is copied unchanged.
Video to GIF
Convert part of an MP4, MOV, WebM or MKV video into an animated GIF, with start and end times, width, frame rate and loop count. A GIF holds up to 600 frames, such as 60 seconds at 10 fps.
Trim video
Cut a clip out of an MP4, MOV, WebM or MKV video by start and end time. By default the video and sound are copied without re-encoding, so it is fast and the quality is unchanged; exact cutting re-encodes the video to start on the exact frame.