How to make an image background transparent
- Drop an image on the box, click it, or paste one with Ctrl+V. A sample logo loads first.
- The tool reads the most common color along the edges and fills in Background color to remove. To change it, click the picture, use the color box, or type a hex code such as #00b140.
- Set Tolerance (0 to 150) and choose From the edges or Everywhere. Leave Soften edges ticked for smooth cut edges.
- Check the cut-out under Preview on Black or White, then click Download PNG.
How the background is removed
For every pixel the tool measures how far its color is from the background color, as the straight-line distance in RGB: the square root of (red difference squared + green difference squared + blue difference squared). It runs from 0 for identical colors to about 442 for black against white. Pixels at or below Tolerance become fully transparent. With Soften edges on, pixels between Tolerance and 1.5 times Tolerance fade out in proportion to their distance, and existing transparency is kept: the new opacity is the old opacity times the fade.
In From the edges mode a flood fill starts at the border and spreads up, down, left and right through matching pixels only, so a matching color enclosed by your subject stays. The result is a PNG with an alpha channel, read and written through the canvas (getImageData).
Worked example
The sample logo is 280 x 200 px, or 56,000 pixels: a blue badge with a white ring and check mark on white. The detected color is #ffffff. At Tolerance 30 with From the edges, the status reads 63.7% of the picture is now transparent (35,648 of 56,000 pixels), and the ring and check mark stay white. Choose Everywhere and it reads 69.9% (39,126 of 56,000 pixels), because the ring and check mark are removed too and leave holes in the badge.
Limits and edge cases
- Only flat backgrounds work. Gradients, shadows and busy scenes leave a ragged cut, because the tool compares colors and does not recognise objects.
- Soft edge pixels keep some of the old color. If a light fringe shows on the Black preview, raise Tolerance. A tolerance of 0 removes only the exact color.
- The output is always PNG, because JPG cannot store transparency. Pictures above 25 megapixels are scaled down to fit.
- iPhone HEIC photos do not open here. Convert them with the HEIC to JPG converter first.
- Trim the border first with the image cropper, or shrink the result with the image compressor, whose WebP output keeps transparency.
Transparent background FAQ
How do I remove a white background from an image?
Add the image, keep the detected white as the background color and From the edges selected, then raise Tolerance until no light fringe is left and click Download PNG. White areas inside your subject stay in place.
Why is there a light halo around my cutout?
Edge pixels are a blend of your subject and the old background. Raise Tolerance a little so they fade out, check the result on the Black preview, and start from a PNG when you can, because JPG compression adds noise near edges.
Why did the white inside my logo stay, or disappear?
From the edges removes only the color that connects to the border of the picture, so white inside a logo stays. Choose Everywhere to remove every pixel of that color, including areas inside the subject.
Can it remove the background from a photo of a person?
Only when the background is one flat color, such as a green screen or a white studio sheet. This tool compares colors and does not recognise objects, so a busy background needs a tool that detects the subject.
What tolerance should I use?
Start at 30. Use 10 to 20 for clean PNG logos on flat color, 40 to 70 for JPG pictures with a noisy background, and stay below 100 or the edges of your subject start to wear away.