Free Online Video Compressor
Make MP4, MOV, MKV, AVI, and WebM videos smaller in your browser. See the estimated size before you start. No install, no watermark, no account needed.
Drop your video here
Or click to browse. MP4, MOV, MKV, AVI, or WebM.
- Up to 250 MB per video
- 5 free videos per day
- Files deleted after 24 hours
How it works
Three steps. The compression runs on our servers with FFmpeg, so it works the same on a phone or a laptop.
1. Upload
Drop a video up to 250 MB. It goes straight to private cloud storage over HTTPS.
2. Choose a level
Pick Fast & Light, High Efficiency, or Maximum Savings, and an output format. Each level shows the estimated size.
3. Download
Preview the result and download it. The file is deleted from our servers after 24 hours.
Which level should you pick?
Start with the lightest level that fits your size limit. Less compression means more of the original quality survives.
| Level | Codec | Typical size | Use it for |
|---|---|---|---|
| Fast & Light | H.264 | About 75% of original | YouTube uploads, older computers, anything that must play everywhere |
| High Efficiency | H.265 | About 45% of original | WhatsApp, email, Discord, saving storage |
| Maximum Savings | H.265, slow preset | About 25% of original | Very tight limits; expect some softness in busy scenes |
Know your limit before you compress
Free references we maintain alongside the compressor.
Video size calculator
Find the bitrate that fits 16, 20, or 25 MB, or estimate how big a video will be.
Upload limits by app
Current maximum file sizes for WhatsApp, Discord, Telegram, Slack, Gmail, and more.
All guides
Practical articles on codecs, bitrate, phones, and sharing big videos.
Latest guides
- CRF vs Bitrate: Two Ways to Control Video Compression9 min read
- How to Calculate Video File Size (and the Bitrate for a Size Limit)6 min read
- How to Compress a Video on Android (Samsung, Pixel, and Others)7 min read
- How to Compress a Video on iPhone: Settings, Trimming, and Sharing8 min read
- How to Compress Screen Recordings Without Blurry Text7 min read
- How to Send Large Video Files: Every Option Compared7 min read
Frequently asked questions
Is BoltCompress free?
Yes. You can compress up to 5 videos per day, up to 250 MB each, without an account or payment. There are no watermarks. The site is funded by ads.
How much smaller will my video get?
Fast & Light keeps about 75% of the original video bitrate, High Efficiency about 45%, and Maximum Savings about 25%, so the file shrinks by roughly a quarter, a half, or three quarters. Videos that were already heavily compressed shrink less. The tool shows an estimate before you start.
Will I lose quality?
Compression is lossy, so some information is always removed. With Fast & Light and High Efficiency the difference is hard to see for most phone footage. Maximum Savings can soften busy, fast-moving scenes. Resolution and frame rate are not changed.
Which formats are supported?
You can upload MP4, MOV, MKV, AVI, or WebM, and choose any of them as the output. MP4 is the best choice for sharing because it plays everywhere. WebM output uses VP9 and AVI output uses H.264.
What happens to my videos?
Files are uploaded over HTTPS to private storage under a random name, compressed automatically, and deleted after 24 hours. Nobody watches them, and they are never reused. Details are in our Privacy Policy.
Why will my compressed video not play?
High Efficiency and Maximum Savings use H.265, which some older computers cannot play. Choose Fast & Light (H.264) for maximum compatibility, or open the file in a player such as VLC.
Still stuck? Contact us or read why compressed videos look blocky.