Free online video compressor (no upload)
Make a video smaller in your browser. It never leaves your device.
Compress a video
Pick Small file, Medium, High quality or a size in MB, like 25 MB for email or 20 MB for Discord, then download the MP4.
The compressor needs JavaScript, which is off or blocked in this browser. On Android, the free OctoZip app compresses videos on your phone: get it on Google Play.
This browser can’t compress video on this page. The compressor uses the browser’s own video encoder, which recent Chrome and Edge have, on Android and on computers. Open this page in one of those, or on Android use the OctoZip app, which compresses videos on your phone.
Get OctoZip on Google PlayMP4, MOV, WebM or MKV, up to about 2 GB. Works in recent Chrome and Edge, on phones and computers.
Reading the video…
Compressing… 0%
Keep this tab open and the screen on until it finishes. Switching to another app can pause it.
How does it work?
The page uses your browser’s own video tools to read the video, make a new copy of the picture at a lower bitrate (and, if you like, a lower resolution) and save it as an MP4 file. The sound is copied across as it is when it can be. All of this runs on your phone or computer, the same idea as the OctoZip app on Android, so the video never leaves your device.
- Choose a video. The page shows its size, length and resolution.
- Pick a setting. Each one shows an estimate of the new size before you start.
- Compress. A progress bar shows how far it has got; you can cancel at any time.
- Check and download. Play the new copy on the page, then download it or, on a phone, share it straight to an app.
The new copy is an MP4 with an H.264 picture, the kind of file almost every phone, computer and app plays. Once the page has loaded, it works even with your connection switched off.
Which setting should I choose?
Medium suits most videos you want to send. Small file is for chats and email when size matters most, High quality for videos you want to keep sharp, and Target size when the place you are sending it to has a limit.
| Setting | What it does | That minute becomes about |
|---|---|---|
| Small file | About a third of the resolution: 1080p becomes 360p, 4K becomes 720p | 6 MB |
| Medium | Half the resolution: 1080p becomes 540p, 4K becomes 1080p | 12 MB |
| High quality | Keeps the resolution, at a lower bitrate | 47 MB |
| Target size | Works out the bitrate and resolution that fit the size you type | Just under your size |
Resolution follows the setting unless you pick one: 1080p, 720p or 480p. The compressor never makes the picture bigger than the original, and never gives it a higher bitrate than it had. Why lower settings make smaller files is explained in video bitrate explained and 720p vs 1080p vs 4K.
What size should I aim for?
Under the limit of wherever you are sending it, with a little room to spare:
| Where | Limit | More |
|---|---|---|
| WhatsApp, video in a chat | 64 MB for any video sent or forwarded; 100 MB at up to 720p as a default on a faster connection; 2 GB as a document | Send big videos on WhatsApp |
| Gmail, personal account | 25 MB per email; bigger files become a Google Drive link | Send a video by email |
| Outlook.com | 25 MB for the whole email | Email attachment limits |
| Discord, free account | 20 MB a file (50 MB with Nitro Basic) | Compress for Discord |
Or open the compressor already set for where the video is going: WhatsApp, email, Discord, Instagram, TikTok, YouTube, a screen recording or 4K video. Why each setting is what it is: video compressor settings for every app.
How long a video fits: at 1.5 Mbps a minute takes about 11 MB, so 25 MB holds about two minutes. Look up any service in the video size limit checker, and see how many MB a minute of video takes at each resolution.
How big a video can I compress here?
Videos up to about 1–2 GB work on most phones and computers. The page reads the video in small pieces and, in most browsers, writes the new copy straight to your device’s storage as it goes, so it doesn’t need the whole video in memory. The browser does need free storage of about the size of the new copy, and a long video takes a while.
On our test laptop (a Mac with Apple silicon, in Chrome), a 30-second 1080p video took about 4 seconds with Medium, and a 10-second 4K video about 6 seconds with High quality. Phones are slower, and a phone can pause the page when the screen locks or you switch apps, so keep it open until it finishes.
Bigger files, many videos, or no browser? OctoZip for Android
The OctoZip app compresses videos on your phone and never uploads them. It’s free with no ads, compresses files up to 3 GB free, and lets you compare the copy with the original before saving. OctoZip Pro adds batch compression, files over 3 GB, 8K videos and four more presets.
Get it on Google PlayWhich files and browsers work?
- Files: MP4, MOV, M4V, WebM and MKV, from phones, cameras and screen recorders. AVI, WMV and FLV files can’t be read. The new copy is always an MP4.
- iPhone videos (HEVC) work when the browser can play HEVC itself, as Chrome and Edge do on most recent computers and phones. If yours can’t, the page says so.
- Browsers: made for recent Chrome and Edge, on Android phones and on computers. Safari can compress too, more slowly, and sometimes stops part way on a video; if it does, try Chrome. A browser that can’t encode video itself gets a message instead of the compressor.
- HDR videos are saved in standard range, so their colours can look a little flatter.
More on formats in MP4 vs MOV vs MKV and HEVC vs H.264.
Questions
Is this video compressor really free?
Yes: no sign-up, no watermark and no daily limit. It runs on your own device, so there’s no server time to pay for.
Is my video uploaded anywhere?
No. Your video never leaves your device: the browser reads it and makes the smaller copy right there. The privacy policy says what the website itself counts.
Will compressing make the video look worse?
A little. A smaller file always holds less detail. High quality keeps the resolution and looks close to the original on a phone screen; Small file looks softer, especially on a big screen. Watch the preview before you download. More in does compressing a video reduce its quality?
Can I compress a video to exactly 25 MB?
Choose Target size and type 25. The compressor aims about 5% under it, and if the copy still comes out over, it makes it once more at a lower bitrate. It can’t make a long video tiny: below a certain size it tells you the smallest size that still looks like video, so you can trim it first. See compressing a video to a specific size.
Does it keep the sound?
Yes. The sound is copied across as it is when an MP4 can hold it, as it can for most phone videos. Otherwise, or when a small target size needs the room, it is re-encoded.
Why isn’t my compressed video much smaller?
It was probably compressed hard already, for example a video saved from WhatsApp. The compressor never raises the bitrate, so at the same resolution there is little left to save. Try Small file or 480p.
Can I compress several videos at once?
Not here; it does one video at a time. Batch compression is in the OctoZip app on Android, with OctoZip Pro.
Does it work offline?
Yes, once the page has loaded: it needs no connection to compress.
Sources
- The browser’s video encoder and decoder: MDN, WebCodecs API. Checked on 1 November 2026.
- Reading and writing the video files: Mediabunny 1.61.6, an open-source library under the Mozilla Public License 2.0, served from this site unmodified.
- Better results below 720p at 1.5 Mbps or less: Android Developers, Best practices for sharing video. Checked on 1 November 2026.
- Size limits: WhatsApp Help Center (and its page on longer videos), Gmail Help, Microsoft Support (Outlook.com) and Discord Support. Checked on 28 October 2026.