Compress video
Make videos smaller to send, upload or keep. Your browser’s built-in encoder does the work — no upload, no watermark, no sign-up.
Preset
Files never leave your device. Everything runs in this tab — nothing is uploaded.
…
Keep this tab open and the screen on — Safari on iPhone pauses background tabs.
This tab was in the background, so the browser may have paused the work. If it stalled, run it again with the tab open.
Same thing for your whole library?
Get it on the App StoreClear Cleaner compresses all your large videos on the iPhone in one go and keeps their original date and albums.
How it works
- The page uses WebCodecs — the video encoder built into your browser and usually backed by your device’s hardware — instead of a 25 MB ffmpeg download.
- The file is read from disk in pieces by Mediabunny inside a Web Worker, re-encoded to H.264 and packed into an MP4 that plays on iPhone, Android, Windows and in browsers.
- Audio from an iPhone (AAC) is copied as is when possible, so voices don’t lose quality.
Good to know
- Keep the tab open and the screen on. iOS pauses background tabs, so compression stops if you switch apps.
- On iPhone, files above roughly 600 MB can make Safari run out of memory. Use a computer for long 4K clips — or the app, which works with the whole library.
- HEVC (H.265) — the iPhone default — decodes in Safari and in Chrome or Edge on most Macs and Windows PCs, but not in Firefox.
- One video at a time.
Questions
Are my files uploaded anywhere?
No. The file is read and converted by your browser in this tab. You can check it yourself: open the developer tools, switch to the Network tab and run a conversion — no request carries your file.
How much smaller will my video get?
It depends on the source. A 4K iPhone clip at “Balanced” often shrinks by 80–90%; a video that was already compressed by a messenger may shrink very little. You see the exact sizes before you download.
Is there a watermark or a size limit?
No watermark. The only limit is your device’s memory: computers handle multi-gigabyte files; on iPhone keep it under about 600 MB.
Does it work on iPhone?
Yes, in Safari on iOS 16.4 or later. Keep the tab open until it finishes — iOS pauses background tabs.
Why is it faster on some devices than others?
The browser hands encoding to the device’s hardware video encoder when there is one. Recent iPhones, Macs and PCs do it several times faster than real time.