Compress video online - shrink MP4, MOV and WebM to a target size in MB

Quality preset sets the video bitrate from the number of pixels: width × height × 30 fps × factor, where the factor is 0.1 for Light, 0.06 for Balanced and 0.035 for Strong (never below 150 kbps). Audio is re-encoded at 128 kbps, or 96 kbps with Strong.

• 1920×1080: Light 6.2 Mbps, Balanced 3.7 Mbps, Strong 2.2 Mbps (about 47, 28 and 16 MB per minute of picture).
• 1280×720: Light 2.8 Mbps, Balanced 1.7 Mbps, Strong 1 Mbps (about 21, 12 and 7 MB per minute).

A 1080p phone clip is usually recorded at 12-20 Mbps, so Balanced typically makes it 3-5 times smaller without a visible difference on a phone or laptop screen.

Target size works backwards from the limit you type. Before you click the button, the “Estimated size”, “Video bitrate” and “Output resolution” boxes show what you will get.

The tool divides your budget by the duration, keeps a 4% safety margin for container overhead and subtracts the audio:

video bitrate = MB × 8,000,000 ÷ seconds × 0.96 - audio bitrate

Example: a 60 second clip squeezed into 10 MB gives 1,280 kbps in total; minus 128 kbps of audio that leaves about 1,150 kbps for the picture. Audio gets at most 128 kbps but no more than about 15% of the budget (minimum 32 kbps), so a 5 minute video into 25 MB keeps 96 kbps of sound and about 544 kbps of video.

The result usually lands a few percent under the target rather than over it. If the video bitrate drops below 150 kbps the tool warns you that the picture will look very poor - lower the resolution or raise the limit.

1. Resolution - 1080p has 2.25 times more pixels than 720p, and 4K has four times more than 1080p. The limit applies to the shorter side, so a vertical 1080×1920 video counts as 1080p. Videos are never upscaled.
2. Bitrate - lower bitrate means a smaller file and more visible blocking in fast motion.
3. Length - cut what you do not need first with Trim video.
4. Sound - if the clip does not need audio, remove it and give the whole budget to the picture.

Want to plan the numbers before encoding? The video bitrate calculator shows the size for any bitrate and duration.

Compression runs on your own device with WebCodecs, often hardware accelerated. The video is not uploaded anywhere, and you can cancel at any time from the progress bar.

• The output keeps the source container (MP4, MOV, WebM or MKV). If the browser has no encoder for it, the result is saved as WebM and a warning appears.
• MP4 and MOV are encoded with H.264 when available; without an H.264 encoder you will see a compatibility warning, as older devices may not play other codecs.
• Speed depends on your hardware: from a few seconds for a short clip to several minutes for a long one. Chrome and Edge are the most reliable.
• An already heavily compressed video may not shrink further - try a stronger preset or a lower resolution.