Image Resizer

Shrinking is safe. You are throwing pixels away, and the tool does it in halving passes rather than one big jump, because a single draw that reduces by more than about 2× samples too few source pixels and turns fine texture into speckle and moiré. Enlarging is the risky direction, and no resizer escapes it: making an image bigger cannot add detail that was never captured. The extra pixels are interpolated from their neighbours, so edges soften and the result looks slightly out of focus — mildly at 120%, obviously past 200%. If you need a larger image, go back to a larger original wherever one exists.

Keeping the source format is the safe default and the one selected here. If you are choosing: JPG for photographs, WebP when you want the same photograph noticeably smaller and every browser you care about is recent, PNG for screenshots, logos, line art or anything with transparency. Note that JPG has no alpha channel, so a transparent PNG converted to JPG has its transparency flattened onto white here. Our Image Converter covers format changes on their own, with a choice of background colour.

Dimensions and file size are related but not the same lever. Halving both sides quarters the pixel count, which usually shrinks the file a lot — but the encoder still decides how many bytes each of those remaining pixels costs. A PNG of a photograph stays big at any size because PNG is lossless and photographs compress badly losslessly, and a JPG saved at quality 100 spends far more bytes than one at 80 for a difference few people can see. If the pixel dimensions are already where you want them and the file is still too heavy, the fix is compression, not more resizing: Image Compressor lets you set a quality level or aim at a target file size.

No. There is no server involved in the resize. Your files are read by the browser, drawn to a canvas, and encoded back to a blob entirely on your own machine — the page has no upload endpoint to send them to. That is also why it keeps working if you go offline after the page has loaded, and why there is no account, no queue and no file-size cap beyond what your own memory allows.

Not well. This tool uses smooth interpolation, which is right for photographs and ruinous for pixel art: it averages neighbouring pixels into new in-between colours, so the hard boundaries that define the artwork turn into soft gradients and the palette fills up with shades the artist never chose. Pixel art needs nearest-neighbor sampling at whole-number factors instead, which is what Pixel Art Upscaler does — every source pixel becomes an identical solid block, and nothing is blended.