Image resizer.

Lanczos-3 computes each new pixel from its neighbours up to three pixels away on every side (a wider span when shrinking), weighted along a windowed sinc curve, which keeps edges crisp and stops fine patterns (fabric, roof tiles, screen text) from turning into moiré. Smooth halves the picture with the browser's own filter until it's close, then scales once: softer, and quicker on huge files. Pixel copies the nearest pixel, the right choice for pixel art, QR codes and icons scaled up by whole numbers.

Making a picture smaller throws pixels away but loses nothing you could see at the new size, as long as the filter averages properly, which Lanczos does. Making it bigger can't add detail that was never captured: every method only guesses the in-between pixels, so a 400-pixel logo blown up to 2000 will look soft. Start from the largest original you have.

They apply when the box has another shape than the picture. Cover fills the box and trims what overflows, keeping the centre. Contain fits the whole picture inside and fills the bands with a blurred copy of itself, a color, or transparency. Stretch fills the box by distorting the picture, which is rarely what you want for photos.

Twice the size it's displayed at, so it stays sharp on high-density screens: a photo shown 800 pixels wide on a page wants 1600. Full-width hero images rarely need more than 2400 pixels across. Past that, the extra pixels cost bandwidth and add nothing anyone sees.

No. Each file is decoded, resized and encoded again by your browser, and the page makes no request with it.

Yes. Drop as many as you like; the preview shows the one selected in the strip, and Download all as ZIP writes every file with the same settings, one after another, so only one picture is held in memory at a time.

With the ratio kept, the side you typed last sets the size: type a width of 1080 and every picture comes out 1080 pixels wide, each with the height its own proportions give, so a portrait and a landscape both stay undistorted. Unlock it and every file comes out at exactly the width and height shown, using the fit you choose.

Up to 16,384 pixels on a side and 100 megapixels in all, about what a browser canvas holds (phones hold less). A bigger request is declined with a message instead of failing silently.

No. The "Image resizer" tool is free and opens without a sign-in, an account or an install.

Percent at 50%, Lanczos resampling, the photo's own format at quality 90. Switch to Pixels and the width and height start from the current result, so you can type over them.

Instagram square, portrait and story, X post and header, LinkedIn post and banner, Facebook post and cover, YouTube thumbnail and banner, a Pinterest pin and the Open Graph image, plus HD, Full HD, QHD and 4K screens, phone and tablet wallpapers and a 512-pixel app icon.

Your file's name with the new size and the format's extension: photo.jpg resized to 1080 wide becomes photo-1080x720.jpg. In a ZIP every file carries its own size, since kept ratios differ from picture to picture.

Up to 16,384 pixels on a side and 100 megapixels in all. Each source file can be up to 100 MB.

Closest to the "Image resizer" tool: Image compressor, Social media image resizer, Image cropper, Image converter. Each opens on its own page, free and in the browser.

The "Image resizer" tool is one of 18 in its group. The group's page, /tools/image, lists them all.

The tool is free. Its interface is built from shadcn.io's own components (Button, Input, Slider and the rest of the registry under /ui), which come in React, Vue, Svelte and Solid. Pro adds the blocks and templates for the product around it.