Resize JPEG, PNG, or WebP images to a target width and/or height while preserving aspect ratio. Processing stays in the browser—your file never leaves the device.
Sizing rules
- Width only — height scales proportionally
- Height only — width scales proportionally
- Both width and height — the image fits inside the box (contain mode); the larger dimension hits the target and the other scales down
Dimensions are computed with integer pixel rounding. Output format matches JPEG sources as JPEG (quality 92) and PNG/WebP sources as PNG.
When to use it
- Generate thumbnails for documentation or social previews
- Downscale oversized camera photos before upload
- Normalize asset dimensions for a design grid
Limitations
Upscaling small images does not add real detail. EXIF orientation may not auto-apply in all browsers. Very large sources can exceed canvas memory limits. No crop or sharpen filters are applied—only proportional scaling.
Example
For example, enter the default sample values on the form and compare the output with a known reference; adjust one input at a time to see how the result changes.