Fix blue underwater iPhone video
Phones in a dive housing record beautiful detail and terrible color. This free tool corrects the blue cast per frame, in your browser, without sending the clip anywhere. It reads HEVC and H.264 from iPhone and Android, including 10-bit.
Before you record
- Turn off HDR video on iPhone (Settings → Camera → Record Video → HDR Video off). Dolby Vision HDR clips cannot be decoded by browsers; standard HEVC and H.264 can.
- Lock exposure and focus in the housing's camera app if it allows it – the correction is steadier when the phone is not hunting.
- 4K30 is the sweet spot for phones: plenty of detail, and it processes quickly.
Correcting the clips
- Transfer the videos to a computer (AirDrop, cable, iCloud, Google Photos "download original"). Keep the original files – re-encoded "compatible" exports lose quality.
- Open the app in Chrome or Edge, drop the clips in, press Start.
- Each clip is analysed separately: a snorkelling clip in milky water gets a gentler preset than a reef clip at fifteen metres.
On the phone itself: Android with Chrome works today. Safari on iOS 17 and newer runs the tool in beta – finished videos get a Save button that puts them into Photos. If your phone struggles with 4K, the tool falls back to 1080p output automatically.
Why not an app?
Most phone apps for underwater color are free to try and then charge to remove a watermark or to export more than a clip or two a day. They also process on the phone, which limits resolution and battery. This tool is free, runs on your computer's graphics card at full resolution, and the optional watermark costs nothing to switch off. See the comparison of underwater color correction apps.
Frequently asked
My iPhone clip says 'Dolby Vision is not supported'. What now?
The clip was recorded with HDR Video on. Export it as SDR from the Photos app (Share → Options → disable 'All Photos Data', or convert with a 'most compatible' export), or turn HDR Video off for future dives.
Does it work with Android phones?
Yes – MP4 and MOV in H.264 or HEVC from any phone. Samsung's 'HEVC' option (10-bit) is supported.
Will the corrected video keep its audio?
Yes, the audio track is copied unchanged.
Can I run it on the phone without a computer?
Android with Chrome: yes. iPhone: Safari on iOS 17 or newer, in beta. Large 4K clips take longer on a phone and the screen must stay on.