Colorize a GIF.

To colorize a GIF is to change the colour of every frame in it. This tool makes a GIF black and white or sepia, inverts it, tints it with one colour, paints it with two colours for a duotone, or shifts the hue and sets the saturation, brightness and contrast. The preview plays with your colours as you choose them, and the new GIF is written in your browser with its size shown next to the old one. It does not guess the real colours of an old black and white clip. To give such a clip a colour cast, use Tint or Duotone.

How to colorize a GIF

1. Drop a GIF on the box, click to choose one, or paste one. It plays in the preview straight away.
2. Click a button under Quick looks, such as Sepia or Duotone, to start from a ready made look.
3. Change the look under Colour look. Strength mixes the look with the original colours. Tint colour, Shadows and Highlights pick the colours for a tint or a duotone.
4. Fine tune with Hue shift, Saturation, Brightness and Contrast under Adjust. They are applied first, then the look.
5. Click Compare with the original and drag the white line on the picture to see before and after side by side.
6. Click Download the GIF. Reset all puts every setting back, and Choose another GIF starts again.

What each look does

Take one pixel with red 200, green 100 and blue 50. These are the numbers each look gives it.

The grey uses weights of 0.299, 0.587 and 0.114, which count green as the brightest of the three channels, as the eye does. The sepia numbers are the standard sepia matrix, the one browsers use for the CSS sepia filter.

Tint and duotone

Both look at how bright each pixel is and replace its colour from a ramp. Tint uses a ramp that goes from black, through your colour at the middle, to white, so the darkest and lightest parts stay dark and light and the middle takes the colour. Duotone goes from your Shadows colour to your Highlights colour, so every pixel becomes some mix of the two. Duotone is a good way to bring a mixed colour GIF into one brand palette, or to give a black and white GIF a colour.

Hue shift

Hue shift turns the colour wheel by a number of degrees, from minus 180 to 180. Pure red at 180 degrees becomes a teal of 0, 109 and 109. Saturation at 100% leaves colours as they are, 0% removes them all and 300% pushes them hard. Brightness and Contrast at 0 leave the picture as it is.

File size and what is kept

• The size before and after is shown above the download. The tool writes only what changed from frame to frame, so the new GIF is not larger for no reason.
• When the new colours fit in 256 per frame, which they do for most looks on a GIF, they are written exactly as worked out. A photo GIF that ends up with more than 256 colours in a frame is matched to 256, so smooth gradients can show faint steps.
• If the new file would be bigger than the old one, the tool tries again by merging tiny colour differences, and says so. If it is still bigger, it says that too, and the GIF compressor can shrink it.
• See-through parts stay see-through, the size stays the same and the loop setting is kept. A frame time shorter than 0.02 s is set to 0.1 s, the way browsers show it.

Need words on the GIF after the colour change? Use add text to a GIF. To change the colours of a photo, try colorize photo or invert colours.