🗜️ Video Compressor ☆

Compress video to a target size

Free Video Compressor re-encodes any video to fit a target size, perfect for email, chat or upload limits. Everything happens locally with FFmpeg (WebAssembly) using two-pass H.264, so quality stays as high as the bitrate budget allows.

How it works

• Drop an MP4, MOV, WebM or MKV file above
• Set the target size in MB (or pick a quality level)
• Compress and download the smaller file

Good to know

• Two-pass encoding spends the bitrate where it matters most
• Very small targets mean lower resolution or softer details. That is normal
• No upload: your video never leaves the browser

How video compression works

The tool targets a size you choose, typically just under a platform upload limit, and calculates the bitrate that fits within it for the clip's duration. It then encodes with FFmpeg in the browser, optionally using two passes so the quality is distributed evenly instead of degrading at complex scenes. Resolution and codec stay as close to the original as the target allows, and the result is written as a standard MP4 that plays everywhere.

Formats, limits and parameters

Privacy: the video never leaves the device

Videos often contain family moments, client work or unreleased material. Compression runs in the browser with WebAssembly: nothing is transmitted, stored or logged, and closing the tab clears everything.

Compression tips

• Set the target just below the limit of the platform you are uploading to.
• Use two-pass encoding for clips where quality consistency matters.
• Trim first, then compress, shorter clips compress better at the same size.
• Long videos process faster on a desktop with more memory.
• Keep the original until the compressed file plays correctly.

Related: browse the conversion tools for trimming, GIF and audio extraction.

Codecs, quality settings and resolution trade-offs

Compression is a negotiation between size, quality and processing time, and knowing which dial does what prevents wasted effort. The codec is the biggest factor: H.264 plays everywhere, H.265 (HEVC) saves roughly 30-50% at the same visual quality but is slower to encode and less universally supported, while VP9 and AV1 compress better still at the cost of much longer encoding. In constant-quality mode a lower CRF number means higher quality, 18 is visually near-lossless, 23 is a good general default, and 28-32 suits previews and messaging. Constant-bitrate mode is only worth choosing when a platform imposes a bitrate ceiling. Resolution is usually the most effective lever: dropping from 1080p to 720p removes more than half the pixels, and phone screens rarely show the difference. Frame rate matters for motion, not detail, so 30 fps is fine for talking-head video and 60 fps only for games and sport. Audio should not be forgotten: 128 kbps AAC is transparent enough for speech, 192 kbps for music. Finally, check whether hardware acceleration is available, because it can cut encoding time several-fold. The tool reports the before-and-after size so you can compare settings instead of guessing, and everything runs locally on your device.