pngtoolskit.org
PNG and image utilities, in the browser
Say hi →

Background

replace transparency · or remove a colour (chroma key)

Two modes: Fill replaces transparent pixels with a colour you pick (good before exporting to JPG, or for a coloured matte). Remove deletes pixels matching a colour (good for crude background removal — works best when the original background is a solid colour).

Drop image files here

Multiple files allowed

    no files
    Ready.

    When to use this tool

    Fill mode is for when you'll export to a format without alpha (JPG) and want a specific background colour rather than the default white. Remove mode is a crude background-removal — it works well for logos / icons on a solid background, less well for photos.

    Tolerance

    Tolerance controls how close a pixel must be to the picked colour to be considered "background." 0 = exact match only. 20 (default) handles slight anti-aliasing. 50+ starts removing chunks of foreground.

    Use cases

    FAQ

    Why does my photo's background not come out cleanly?

    Photo backgrounds aren't a single colour — they have shadows, gradients, and texture. This tool only handles solid-colour backgrounds. For photos, use a dedicated tool with AI segmentation.

    What format is the output?

    Always PNG (so transparency is preserved when removing colour).