Reduce image size

Two levers do it: re-compress to an efficient format (WebP or AVIF cut a photo dramatically versus the original), and reduce the pixel dimensions if the image is larger than it needs to be on screen. This page opens with both ready - the resize panel is already open - so you can do both in one pass.

It can, and you decide how much. Re-compression trades a little quality for a lot of weight, controlled by the quality slider; resizing the dimensions is lossless in the sense that a smaller image simply has fewer pixels. The before/after slider shows exactly what you are giving up.

Yes by default - Maintain aspect ratio is on, so setting a width fills in the matching height automatically and the image is never stretched. Turn it off to choose Stretch, Cover (crop to fill), or Contain (fit the whole image with transparent or coloured padding) for exact dimensions.

No. Decoding, resizing, compression and ZIP packaging all run inside your browser using WebAssembly codecs. Your images never leave your device and nothing is sent to a server, so it works offline and is safe for private photos.

Yes. Drop multiple files, a folder or a ZIP. Each image keeps its own settings (a new one inherits whatever you last used); to apply the current settings to several at once, select them and use "Apply current settings". Download them individually or as one ZIP.