When this tool is useful
Avatars, cards, thumbnails, and UI assets that need consistent corner geometry.
How local processing works
The browser expands the canvas by the selected border width, fills the border with the chosen color, applies a rounded-rectangle outer mask, and writes PNG.
How to use it
- Prepare Round image corners: Work from a copy and confirm border width, border color, outer corner radius, transparent outside corners, subject safe area, resulting dimensions, and display scale. Keep the source unchanged.
- Apply Round image corners: Process locally in the browser. The browser expands the canvas by the selected border width, fills the border with the chosen color, applies a rounded-rectangle outer mask, and writes PNG.
- Download and verify: Save under a new name. View corners over contrasting backgrounds, inspect all four edges at 200%, confirm dimensions, and test the target UI scale.
Important limitations
The route exports PNG only; large outer radii remove corner pixels, the mask uses hard pixel edges rather than vector antialiasing, and metadata is removed.
Verify the downloaded result
View corners over contrasting backgrounds, inspect all four edges at 200%, confirm dimensions, and test the target UI scale.
Private by design
Your files stay in this browser. The tool does not upload the source or output to our servers.
Questions and answers
When should I use Round image corners?
Avatars, cards, thumbnails, and UI assets that need consistent corner geometry.
What does Round image corners change?
The browser expands the canvas by the selected border width, fills the border with the chosen color, applies a rounded-rectangle outer mask, and writes PNG.
Which limits and settings matter?
border width, border color, outer corner radius, transparent outside corners, subject safe area, resulting dimensions, and display scale. The route exports PNG only; large outer radii remove corner pixels, the mask uses hard pixel edges rather than vector antialiasing, and metadata is removed.
How do I verify the result?
View corners over contrasting backgrounds, inspect all four edges at 200%, confirm dimensions, and test the target UI scale.