NordriftColor Correction
Donate Start the app →
Free · No upload · 4K60

Give your dive videos their colors back.

Underwater color correction that removes the blue and green cast automatically – and runs right in your browser on your own graphics card. Your video never leaves your computer.

Start the app → Donate Requires Chrome or Edge on a desktop computer. No account, no install.
Hawksbill turtle on a Red Sea reef with a heavy blue cast, before color correction
The same hawksbill turtle after automatic color correction: natural shell, sand and corals
BeforeAfter
Red Sea · hawksbill turtle · GoPro 2.7K · drag to compare
01/ How it works

Three steps. No settings, unless you want them.

The tool measures how much red the water has absorbed, detects the type of scene and corrects every frame with temporal smoothing so colors never flicker.

01

Pick your videos

Drop one file or a whole dive day. MP4/MOV in H.264 or HEVC, including 10-bit from GoPro, DJI and phones.

02

Check before and after

Auto picks a preset for blue water, reef, close-ups or green water. Adjust strength and compare live – or leave it on Auto.

03

Press start

Choose a folder and the corrected MP4 is written straight to your disk while it processes. Audio comes along.

02/ Examples

Drag the line. Every scene type.

Real GoPro frames from the Red Sea, corrected with the preset Auto picked for each scene. Nothing retouched by hand.

Giant moray eel swimming over the reef, before
Giant moray eel swimming over the reef, after
BeforeAfter
Giant moray out for a swimBlue water preset
Eagle ray in open blue water, before
Eagle ray in open blue water, after
BeforeAfter
Eagle ray in the big blueDeep blue preset
Coral reef and sand, before
Coral reef and sand, after
BeforeAfter
Reef and sand at 15 mBlue water preset
Camouflaged octopus next to staghorn coral, before
Camouflaged octopus next to staghorn coral, after
BeforeAfter
Octopus hiding by the staghorn coralReef preset
Camouflaged stonefish lying on a wreck plank, before
Camouflaged stonefish lying on a wreck plank, after
BeforeAfter
Stonefish on the wreckReef preset
Night dive: a Phyllidia nudibranch on the coral, before
Night dive: a Phyllidia nudibranch on the coral, after
BeforeAfter
Night dive · Phyllidia nudibranchClose-up preset
03/ No upload

Your video stays on your computer.

A website does not have to be a server doing work for you. This page is downloaded once and then runs as a program in your browser. The video is read from your disk, decoded and encoded by your graphics card's video engine, corrected by the GPU and written back to your disk. Turn off Wi‑Fi after the page has loaded – it still works.

That is also why it is fast: the frame never leaves the graphics card. No queue, no file size limit, no account.

● your disk → browser (reads the file)
● GPU video engine decodes HEVC/H.264
● GPU shader corrects the colors
● GPU video engine encodes H.264
● browser → your disk (writes the file)
● upload to a server
● cloud processing
● account, cookies, tracking
04/ Features

Built for real dive footage.

Resolution4K · 60 fps · 10-bitHardware decoding of HEVC and H.264 via WebCodecs. Up to 5.3K with HEVC output.
SpeedFaster than real timeTypically 40–60 fps for 4K60 on a laptop with hardware video decoding.
Scene presetsBlue water · reef · close-up · greenAuto-detected per clip, tuned on real Red Sea footage. Override any time.
CorrectionAutomatic red compensationGray-world white balance and percentile contrast, measured per frame and smoothed over time.
BatchMany files at onceQueue a whole dive day, pick one folder and let it run.
OutputMP4 with audioH.264 (HEVC above 4K) at high bitrate. The audio track is copied unchanged – no re-encoding.
05/ Questions

Frequently asked questions.

Does the tool upload my video?

No. The page is downloaded once and then all processing runs as a program inside your browser. The video is read from your disk and written back to your disk. Nothing is sent to Nordrift or anyone else.

Which browsers work?

Google Chrome and Microsoft Edge on desktop (Windows, macOS, Linux, ChromeOS). The tool uses WebCodecs and the File System Access API, which Firefox and Safari do not fully support yet. Mobile is not supported.

How fast is it?

It depends on your GPU. On a typical laptop with hardware video decoding, 4K 60 fps is processed faster than real time, usually 40–60 frames per second. Without hardware decoding the browser falls back to software and gets slower, but it still works.

Which files are supported?

MP4 and MOV with H.264 or HEVC (H.265), including 10-bit footage from GoPro, DJI, Insta360 and phones. Output is MP4 with H.264 (HEVC above 4K) at high bitrate, and the audio is copied unchanged. GoPro telemetry tracks (GPS/gyro) are not carried over.

How does the correction work?

Water absorbs red light first. The tool measures how much red (and optionally blue) is missing relative to green, compensates per pixel, sets white balance with a gray-world estimate and stretches contrast between low and high percentiles. The parameters are measured continuously and smoothed with a median over several frames so colors do not flicker. Scene presets adjust the strength of red compensation, the percentile range and the smoothing window: blue water keeps the water blue instead of cyan, close-ups preserve highlights from torches and strobes.

What does it cost?

Nothing, and there are no limits or watermarks. If it saves you time, you can support development with a voluntary donation.

06/ Reviews

Rated in sea turtles.