Resize an Image for Email
Specify the maximum desired file size (in KB) and the tool automatically adjusts your image's dimensions and JPEG quality through successive iterations to get as close as possible.
How It Works
Many email services limit attachment size or brutally compress photos that are too heavy. Rather than manually adjusting dimensions and quality by trial and error, this tool starts at 85% JPEG quality at the original size, then progressively reduces quality (in 10% steps) and, if necessary, dimensions (in 10% steps), until it gets a file under the target size or reaches a reasonable degradation limit.
Why is the result always JPEG?
JPEG allows fine control over file size through compression quality, unlike PNG, which remains lossless no matter what quality is requested. To hit a precise target size, the image is therefore systematically re-encoded as JPEG, which works very well for photos but can slightly blur text or very fine lines.
What happens if the target size is unrealistic?
If the requested size is too low for the image's dimensions (for example, 20 KB for a high-resolution photo), the tool stops after a reasonable number of iterations and shows you the best compromise it found, with a warning, rather than degrading the image endlessly.
100% local processing: the resizing and iterative compression are done entirely in your browser via WebAssembly — your photo is never sent to a server.