Video Colour Grading & LUTs (Apply, Match & Make LUTs)

About the Video Colour Grading & LUTs (Apply, Match & Make LUTs)

Colour-grade a video in your browser: apply any .cube LUT at the strength you want, turn log footage from Panasonic, ARRI, Fujifilm, Nikon, DJI and Canon cameras into Rec.709, set white balance, exposure, contrast and saturation, push colour into the shadows, mid-tones and highlights with lift, gamma and gain wheels, shape curves, change single colours by hue, or match your footage to a still you like. The preview grades the video live as it plays, with a before/after split and waveform, vectorscope and histogram scopes.

Every grade is turned into one 33-point 3D LUT that your graphics chip applies to each frame, so what you see is what is encoded. With a Pro pass, the whole video is encoded as MP4 with its sound, the grade can be saved as a .cube LUT for your editor or phone app, and any frame as a full-size still. The free preview grades the first seconds of the video, with a watermark. Your video never leaves your device.

The controls, in the order they work

1. Footage: standard video is used as it is; log footage is converted to Rec.709 (see below), with exposure in stops.
2. LUT before the corrections (for a camera maker’s log-to-Rec.709 LUT).
3. Match a reference shot: the colours of the frame on show are moved towards the still’s in the CIELAB colour space, either by their mean and spread (the classic colour transfer) or by their whole histogram, at the strength you set.
4. White balance in linear light: temperature moves the white along the daylight curve of the colour space (warmer or cooler), tint across it (magenta or green), adapted with the Bradford method.
5. Lift, gamma and gain: shadows, mid-tones and highlights, each with a colour push (the wheel) and a darker-or-brighter amount.
6. Contrast as an S-curve that keeps black and white, and saturation that keeps brightness.
7. Curves: one for all channels and one each for red, green and blue, through five points.
8. Colour by hue: hue, saturation and lightness of eight colour bands (red to magenta), worked out in the OKLab colour space, so a change of the oranges does not touch greys.
9. LUT after the corrections (a creative look), at its strength.

Log footage to Rec.709

Each conversion uses the curve and the colour space its maker publishes: Panasonic V-Log and V-Gamut, ARRI LogC3 at EI 800 and ALEXA Wide Gamut, Fujifilm F-Log and F-Log2 (F-Gamut is BT.2020), Nikon N-Log01.pdf), DJI D-Log and D-Gamut and Canon Log 3, recorded in the BT.709 or BT.2020 colour space. The picture is turned into scene light, moved to BT.709 colours with a matrix worked out from the published primaries, given a soft roll-off in the brightest parts (from about 60 % reflectance up) so highlights do not clip hard, and encoded with the BT.709 camera curve, which puts 18 % grey at about 41 %.

This is a neutral, accurate starting point, not a camera maker’s own look. For other curves — Sony S-Log3, Apple Log, Blackmagic Film, Canon Cinema Gamut, DJI D-Log M — load the maker’s .cube LUT and set it to Before the corrections. The page reads whether the file is video range or full range; if a conversion looks washed out or too dark, switch Signal levels.

LUTs in and out

The page reads .cube files with 1D or 3D tables (3D up to 129 points per side), with their DOMAIN_MIN and DOMAIN_MAX, and the shaper-plus-3D files some editors write (a 1D table, then a 3D one, with their input ranges), and samples 3D tables with tetrahedral interpolation. A LUT made for log footage expects that log footage; one made for Rec.709 expects Rec.709, so put it after the conversion.

The LUT you download is the whole grade (conversion, match, corrections and any loaded LUT) as a 33-point 3D .cube file for Rec.709 output, which editors and LUT apps that read .cube files can use on the same kind of footage.

How the video is made

The preview grades each frame at up to 960 pixels on its longest side as the video plays. Grade the video decodes every frame with WebCodecs, grades it on the graphics chip at the size you chose and encodes it again as MP4 (H.264 where your browser can encode it, else HEVC, AV1 or VP9); the sound is copied unchanged where MP4 can hold it, else made AAC. A phone video recorded upright stays upright. In Chrome and Edge on a computer, Save straight to a file writes a long video to disk instead of memory.

Limitations

• Grading needs WebGL 2 and WebCodecs: a current Chrome, Edge, Safari or desktop Firefox with hardware acceleration on. Phones are slower, and very long 4K videos may not fit in a phone’s memory.
• Frames are graded at 8 bits per channel. A strong grade of 10-bit log footage can show banding in smooth skies; a gentler conversion or a little added contrast later usually hides it.
• HDR video (HLG or PQ) is turned into standard range by the browser before grading, so the result is SDR.
• The grade applies to the whole picture: there are no masks, windows or tracking for one part of the frame.
• A file the browser cannot play in the page (for example MKV in Safari) shows one frame at a time in the preview; the graded video is made the same way.

Privacy

On this device: nothing is sent

Your video, your LUTs and your reference pictures are opened in your browser and never uploaded; grading and encoding happen on your device. Only your slider settings are remembered in this browser.

Open-source components

This page can load these open-source components, each only when a task needs it:

• It uses FFmpeg under the LGPLv2.1, through the Mediabunny add-ons: licence and source code.
• It uses the LAME MP3 encoder under the LGPL, through the Mediabunny MP3 add-on: licence and source code.
• It uses Mediabunny under the MPL 2.0: licence and source code.
• It uses the TurboRes ProRes decoder under the MPL 2.0: licence and source code.

You may replace them with your own builds. Their licences and the credits of every library the site uses are on the open-source credits page.