How do I compress a video to reduce its file size?
To compress a video, open FixDoks's Compress Video tool, choose By quality or a target size in MB, pick a maximum resolution such as 720p, then click Compress video. The tool runs inside your browser with WebAssembly, so the file is never uploaded, and it re-encodes to H.264 MP4, usually shrinking the file to a fraction of the original size.
Compress Video at a glance
| Input | MP4, MOV, WebM, MKV, AVI, up to 200 MB |
|---|---|
| Output | MP4 (H.264 + AAC) |
| Processing | In your browser; your files are not uploaded |
| Price | Free, no watermark |
| Download | Free Google sign-in |
| Works on | Chrome, Edge, Safari and Firefox on Windows, Mac, Android and iPhone |
How to use Compress Video
- Click Select video and choose an MP4, MOV, WebM, MKV or AVI file up to 200 MB.
- Pick By quality (Smallest, Balanced or High) or By target size and type the size in MB you need.
- Choose a maximum resolution. 720p is a good default for phones and messaging apps.
- Click Compress video, wait for the progress bar, then preview and download the smaller MP4.
How does video compression work?
A phone video is large because it is recorded at a high bitrate, often 15 to 50 megabits for every second of footage, so the camera never has to throw detail away. Most of that detail is invisible on a phone screen or in a chat window. FixDoks re-encodes the video with the H.264 codec using a smarter rate control setting, and can also lower the resolution. The result is usually a fraction of the original size and looks almost the same.
By quality or by target size
By quality uses a constant quality setting (CRF). The encoder spends more bits on busy scenes and fewer on still ones, which gives the best looking file for its size. Balanced suits most videos. Choose Smallest file for screen recordings and talking-head clips, and High quality when you plan to edit the video again.
By target size is for hard limits, such as an upload form that accepts only 10 MB or an email service that caps attachments. The tool works out the bitrate that fits your duration, encodes, checks the result and does a second, tighter pass if the first one came out too big. For very small targets it lowers the resolution automatically so the picture stays clean instead of blocky.
Which resolution should I pick?
| Resolution | Good for |
|---|---|
| 1080p | Watching on a laptop or TV, YouTube uploads |
| 720p | WhatsApp, Instagram, Telegram, most phone viewing |
| 480p | Email attachments, slow connections, long recordings |
| 360p | Very small files where only the content matters |
The tool only ever scales down. If your video is already 720p and you choose 1080p, it stays 720p. Vertical phone videos are handled correctly: the limit applies to the shorter side.
How long does it take?
Everything runs on your own device, so speed depends on your computer or phone. A one minute 720p clip usually takes a minute or two on a modern laptop. 1080p and 4K sources take longer because every frame has to be decoded and encoded again. If you only need part of the video, cut it first with Trim Video, which makes compression much faster.
Output format
You always get an MP4 file with H.264 video and AAC audio. This combination plays on every phone, browser, smart TV and social network, so you never need to worry about whether the other person can open it. Tick Remove audio if you do not need the sound, which saves a little more space.
Will the file ever get bigger?
No. Some videos, such as ones already exported by an editing app at a low bitrate, cannot be made smaller at the chosen setting. In that case FixDoks gives you back your original file and tells you, instead of handing you a larger one.