Resize images

Always. Setting a width computes the height, and vice versa. Fit inside a box uses the larger reduction so the whole picture fits; nothing is cropped or stretched.

Yes, up to 400% or to an exact size, if you untick Never enlarge. Enlarging cannot add detail: the result is smoother but not sharper than the original.

Large reductions run in halving steps with the browser's high-quality smoothing, so fine lines and text stay legible instead of turning into noise.

By default the same format as the original: PNG stays PNG, JPEG stays JPEG, WebP stays WebP; GIF and BMP become PNG. You can force JPEG, PNG or WebP instead. JPEG and WebP use the quality setting whenever the picture is drawn anew; a picture left at its size in its own format is not drawn again (only its metadata is left out), so the setting does not change it; JPEG has no transparency, so transparent areas are filled with white or black. Metadata such as EXIF and GPS location is not copied.

Results and sources wider or taller than 16,384 pixels are refused with a message: that is this tool's limit. In a batch, a file that fails is skipped and named, and the others still download. Animated GIFs, PNGs and WebPs are resized from their first frame only, even when they keep their size. A WebP result holds at most 16,383 pixels on a side: a larger one is skipped with a message. WebP output is not available in browsers that cannot write WebP (older Safari); the option is then disabled.

No. The page loads a small script into your browser and every operation runs on your device. You can check this yourself in the browser's network panel: after the page has loaded there are no upload requests. Closing the tab discards the file.

No. These basic tools are free and store nothing on our servers. The only limits are the tool's own: sources and results up to 16384 pixels on a side. Within them, the practical limit is your device's memory.

Nothing you open or type. While the tab is open, the tool pages keep a short list of the steps taken in it, in the tab's session storage: the step (page opened, started, succeeded, first success, used again or failed), the tool's name, the time, how many files were used and, for a failure, an error code; never a file name, the contents of a file or your text. It holds at most the latest 200 steps, and the browser deletes it when the tab closes. The page never sends it. Where a Report a problem button is shown, you can attach the last 20 steps to your report; nothing is attached unless you tick that box. In local storage the page keeps only choices you made: a Light or Dark theme until you choose System again, the language you picked with the EN / 中文 switch if it differs from your browser's language, and this tool in your recently used list if you switched that list on at the tools page.