Video Compressor
Make a video smaller so it fits in an email, chat or upload limit. Choose a quality preset or exact bitrate, lower the resolution and frame rate, see the estimated file size before you start, then preview and download the compressed video. Your video is never uploaded.
- Output
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- Video bitrate
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- Original
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- Takes about
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Good to know: the video is re-encoded in real time while it plays in the background, so compressing takes as long as the video lasts (a 3-minute clip takes about 3 minutes). Keep this tab open and visible until it finishes.
How to use the Video Compressor
- Choose a video by dropping it on the box or clicking to browse. A preview and its size, resolution and length appear.
- Pick a quality preset (Balanced suits most videos) or choose Custom bitrate for an exact target.
- Lower the resolution and frame rate for even smaller files, and choose whether to keep the audio.
- Check the estimated size, then press Compress video. It runs in real time, so keep the tab open until it finishes.
- Preview the result and press Download compressed video.
Video file size formula
A video's size depends almost only on its bitrate and length, not on the resolution itself:
File size (MB) ≈ (video bitrate + audio bitrate in kbps) × duration in seconds ÷ 8,000
For example, a 90-second clip at 1,500 kbps video plus 128 kbps audio is (1,500 + 128) × 90 ÷ 8,000 ≈ 18.3 MB. Containers add about 1–2% of overhead. Lowering the resolution matters because fewer pixels need fewer bits to look sharp, which is why the presets scale the bitrate with resolution and frame rate.
Recommended bitrates by resolution
| Resolution | Pixels per frame | Good quality (30 fps) | Small file (30 fps) | Size per minute (good) |
|---|---|---|---|---|
| 1080p (1920 × 1080) | 2.07 million | 4 – 5 Mbps | 2.5 Mbps | about 33 MB |
| 720p (1280 × 720) | 0.92 million | 2 – 2.5 Mbps | 1.1 Mbps | about 17 MB |
| 480p (854 × 480) | 0.41 million | 1 Mbps | 500 kbps | about 8 MB |
| 360p (640 × 360) | 0.23 million | 500 – 600 kbps | 280 kbps | about 4.5 MB |
The Balanced preset uses about 0.07 bits per pixel per frame (for 720p at 30 fps that is about 1.9 Mbps), High uses 0.12, Small 0.04 and Smallest 0.022. Fast-moving footage such as sports needs more bits than a talking head or a screen recording.
Common upload limits
| Where | Typical limit | Tip |
|---|---|---|
| Email attachments (Gmail, Outlook) | 20 – 25 MB | 720p Small or 480p Balanced for clips up to about 2 minutes |
| Discord (free) | 10 MB | 480p or 360p, Small file, audio at 64 kbps |
| WhatsApp video | about 16 MB for best quality | 720p Small; longer videos at 480p |
Limits change over time, so check the service you are sending to. Use the custom bitrate option and the size formula above to hit an exact target.
Frequently asked questions
How do I compress a video to a specific size?
Divide the target size by the length of the video. For a 25 MB limit and a 2-minute video: 25 MB × 8 = 200 megabits, ÷ 120 s ≈ 1.67 Mbps in total. Subtract the audio (for example 0.128 Mbps) and enter about 1,450 kbps as a custom video bitrate. The estimate box shows the result before you start.
Why does compressing take as long as the video?
The tool plays the video in the background and re-encodes each frame with your browser's built-in recorder, which works in real time. This keeps everything private and free of uploads, but a 5-minute video needs about 5 minutes.
Which resolution should I choose?
720p is a good balance for phones, chats and email and is about half the pixels of 1080p. 480p is fine for small previews, and 360p gives the smallest files. The tool never enlarges a video, so higher options are disabled for small videos.
Why is my output WebM instead of MP4?
The output format depends on the video encoders your browser offers. Chrome and Edge 126+ and Safari can record MP4 (H.264), while Firefox records WebM. WebM plays in all modern browsers, Android, VLC and most editors.
Why did my compressed video get bigger?
If the original is already heavily compressed, re-encoding at a higher bitrate can make it larger. Watch the estimate and warning before you start, and choose a lower quality preset or resolution.
Is there a file size limit?
There is no fixed limit, because nothing is uploaded. Very large or long videos need enough memory in your browser to hold the compressed result, so on phones keep videos under a few hundred megabytes.
Is my video uploaded to a server?
No. The video is decoded, re-encoded and saved entirely inside your browser using the canvas, Web Audio and MediaRecorder APIs.