About the Paint Bucket Tool
The paint bucket fills a connected area of similar colour with a new colour in one tap. It is the fastest way to colour a drawing, change a flat background, repaint a logo or turn a white area into a different colour. Use the tolerance slider to decide how similar colours must be to be included, choose between a connected area and every pixel of the same colour, and set the opacity for a see-through fill. Undo any fill, start over and download a full-size PNG. Your picture never leaves your browser.
Updated October 2026
How to use the Paint Bucket Tool
- 1Select an image or drop one on the page.
- 2Pick the fill colour with the colour box.
- 3Set the tolerance: low fills only identical colours, high includes similar shades.
- 4Tap the area you want to fill. Choose Connected area or Same colour everywhere.
- 5Undo if it spilled too far, then Download PNG.
What the bucket is for
Bucket fill is the quick way to change flat colours: colouring in a line drawing, turning a white logo background into a brand colour, repainting a wall in a floor plan or filling a shape in a diagram. It works best on pictures with clear areas of colour rather than on photos.
Tolerance explained
Every colour has red, green and blue values. Tolerance is the largest difference allowed in any of them. A low value such as 0 to 10 fills only pixels that are practically identical. A medium value like 30 includes soft shading in a drawing. A high value such as 100 or more starts to spill into neighbouring colours.
- Flat logos and icons: 0 to 20
- Scanned drawings and anti-aliased edges: 30 to 60
- Photographs: use high values with care and check the result
Connected or everywhere
Use Connected area to fill one region, like the inside of a letter O. Switch to Same colour everywhere to recolour all pixels of that colour in the picture at once, for example changing every white pixel of a logo.
A quick example
Imagine a black outline cartoon with a white background. Choose a pale blue, set tolerance 40 and tap the background. The white background becomes blue but the black outline stays. If the fill leaves a white fringe around the lines, press Undo, raise the tolerance to 70 and tap again.
Phone and computer
On a phone, tap the area to fill; the page does not scroll while you touch the picture. On a computer, click. Pictures up to about 16 million pixels are supported and are saved at full size as PNG.
Good to know
A fill works on pixel colours, so it cannot follow shapes that are not visible as colour boundaries. If a line has a gap, the colour flows through it. For a one-colour swap across a photo, Replace Color in Image gives finer control. For drawn lines use the Brush Tool, and for a flat colour behind the whole picture use Add Background Color to Image.
Features
- One-tap fill of an area
- Tolerance for similar colours
- Connected area or all matching pixels
- Opacity control
- Undo and Start over
- Private: runs in your browser
Frequently asked questions
What does tolerance mean?
It sets how different a colour may be from the one you tapped and still be filled. Zero fills only exactly the same colour. Higher values include more shades.
Why did the fill leak into the rest of the picture?
The tolerance was too high or the outline has a gap. Undo, lower the tolerance and close any gap in the outline with the Pencil Tool.
Why is there a halo of the old colour around the filled area?
Edges of drawings are blended with the background, so those pixels differ slightly. Raise the tolerance a little to include them.
What is the difference between Connected area and Same colour everywhere?
Connected area fills only pixels touching the one you tapped. Same colour everywhere fills every matching pixel in the whole picture.
Can I fill with a see-through colour?
Yes. Lower the opacity and the new colour mixes with the old.
Is my picture uploaded?
No. It stays in your browser.