Image Padding & Border

Pad an image with a solid color (or transparent background) and optionally add a colored border, then either keep equal padding on all sides or fit the result to a target aspect ratio. Useful for Instagram square posts, story aspect ratios, YouTube thumbnails, slide deck consistency, or print frames. Output is rendered to a canvas you can download as PNG, JPEG, or WebP. The image and all processing stay in your browser.

The transparent background only survives in a format that has an alpha channel. PNG and WebP keep it; JPEG has no alpha at all, so exporting to JPEG fills the transparent area with black rather than warning you. If you want a white frame in a JPEG, set the padding colour to white rather than leaving it transparent and hoping.

Fitting to an aspect ratio pads rather than crops, which is the point: nothing is cut off. The consequence is that a tall photo fitted to a 16:9 frame gains wide bars on both sides, and the further the source is from the target the more of the result is padding. If the subject needs to fill the frame, cropping is the operation you want and this is the wrong tool for it.

The file size is set by the output format and not by how much of the canvas is flat colour. A large expanse of one colour compresses extremely well in PNG and reasonably well in WebP, but a JPEG at a middling quality will still put visible noise into it, and a gradient banner padded to square can end up larger than the photo it frames.

Everything happens on the decoded pixels in your browser, so the image is never uploaded, and re-encoding through the canvas drops EXIF, ICC profiles and any embedded metadata the original carried.