Detection uses alpha, not color
Alpha zero is fully transparent; 255 is opaque. The tool finds the outermost rectangle of pixels above the threshold. Opaque white or black backgrounds count as content.
Images
Transparent image trimmer
Remove transparent outer margins and add the padding you need.
Files are processed in this browser.Drop a file or choose one. You can also paste an image.
JPG · PNG · WebP / up to 40 MB and 16 MP / no animation or rotation metadataPreview
Choose a file to begin.
Result
How to use the tool
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Choose a transparent image
Load a PNG or WebP with transparent edges. This tool is not for removing a white background.
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Set threshold and padding
Set an alpha threshold and padding in pixels. Start at zero and adjust while checking whether faint shadows remain.
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Check the crop and save
Generate the result to see the original content coordinates and size. Check the edges, then download the PNG.
Before you export
Threshold versus padding
A higher threshold can exclude faint shadows from the bounds calculation. Pixels inside the resulting rectangle are unchanged. Padding adds new transparent space outside those bounds.
Current limitations
- JPG · PNG · WebP / up to 40 MB and 16 MP / no animation or rotation metadata
- Dimensions must be positive integers, up to 8,192px per edge and 16 MP.
- Alpha threshold 0–254; padding 0–512px on each side. Padded output must fit the dimension limits.
- JPEG usually keeps its full bounds because it has no transparent pixels.
- No output is generated if no pixel exceeds the threshold.
Questions about the image tool
Does this remove backgrounds?
No. It trims existing transparent margins; it does not segment a photo background.
What if a shadow gets cropped?
Lower the threshold. Padding only adds transparent space; it does not restore shadow pixels excluded by the crop.
Are transparent holes inside changed?
No. Only the outer bounds change; pixels inside remain unchanged.
Related guides
All guidesPNG, JPEG, or WebP: which image format should you use?
Choose an image format by transparency, photographic detail, file size, and compatibility rather than by habit.
Read guide →Inspect image pixels, colors and differences
Separate source coordinates from display scale, then use the ruler, color picker and diff tool together.
Read guide →