Image Border Adder
Expand the canvas by a 1–120 px border on every side. Choose a 0–500 px outer radius; outer corners stay transparent and the image is clipped to the corresponding inner radius.
A QUICK WALKTHROUGH
How to use this tool
- Choose a PNG, JPEG or WebP up to 10 MB.
- Choose solid or diagonal gradient, colors, border 1–120 px and radius 0–500 px.
- Preview and download the expanded PNG; input and output must both remain within the pixel limits.
Border and corner geometry
The outer radius is capped at half the smaller output side. The inner radius is max(outer radius − border, 0), capped to the inner box. Radius zero keeps square corners. The source is drawn at its original size with equal borders, while rounded corner pixels are clipped. Pixels outside the outer shape remain transparent.
Input and expanded output limits
Accepts local PNG, JPEG and WebP with matching file signatures, up to 10 MB. Both input and expanded output must be positive, at most 10,000 px per side and 40 megapixels. Decoded pixel buffers have a 256 MB ceiling. Border and radius must be whole numbers in their ranges. SVG and remote URLs are not accepted.
New local PNG
The browser re-encodes a new PNG. Source metadata, color profiles, original encoding and animation are not preserved; only the first animation frame is used. Nothing is uploaded. Changed inputs invalidate pending work, and temporary bitmaps and download URLs are released.
GOOD TO KNOW
Common questions
Does the border shrink the image?
No. It expands the canvas by twice the border on each dimension. Rounded corners can clip image corner pixels.
Can I still use a gradient?
Yes. The two selected colors blend diagonally across the border.
Why can a valid input exceed the output limit?
The border increases width and height. The expanded output is checked again before drawing or export.