tooloora

Resize Image — change dimensions in pixels or percent

Scale photos by percent, exact pixels or presets like Full-HD and passport photo — locally in your browser, no upload.

Runs locally — nothing is uploaded

Drop images here or click

JPG, PNG or WebP · multiple files supported · stays local

Runs locally in your browser – no upload.

Resize an image — locally, no upload

Shrink photos by percent, exact pixels or presets (Instagram square, Full-HD, 4K, e-mail, passport photo) — single files or batches with a ZIP download. Everything runs in your browser: no uploads, no queue, works offline. For maximum sharpness the tool can scale with a Lanczos filter instead of a plain canvas downscale.

How large does my image really need to be?

Usually far smaller than the camera delivers: a 12-megapixel phone photo (4032 × 3024) carries about six times more pixels than a Full-HD display (1920 × 1080, 2.07 MP) can even show. For e-mail and screens the "longest edge 1600–1920 px" presets are almost always enough — and the file often shrinks by a factor of 5–10. 4K (3840) only pays off for large screens or print preparation.

What does "Sharp resize (Lanczos)" do?

A one-step canvas downscale averages too few pixels and turns fine detail into mush. This tool therefore uses either Lanczos3 (WebAssembly, as in Squoosh) or — with the toggle off — multi-step halving, where every step averages cleanly. Lanczos gives the sharpest edges; halving is a bit faster.

Fixed-format presets

The Instagram square (1080 × 1080) and the passport preset centre-crop (cover) instead of distorting the image. The passport size is derived, not guessed: 35 × 45 mm at 300 dpi equals 413 × 531 pixels (35 ÷ 25.4 × 300 = 413).

Honest limits

Upscaling cannot invent detail — the tool warns when a target exceeds the original size. Re-encoding drops EXIF metadata (good for privacy, bad for archives), and giant images above ~16.7 MP are first brought down to the safe canvas limit.

Frequently asked questions

Is my image uploaded to resize it?

No. Resizing happens entirely in your browser — the file never leaves your device. That also makes it fast: there is no upload or download queue.

How do I keep the image sharp when downscaling?

Enable 'Sharp resize (Lanczos)'. It uses a Lanczos filter, which preserves edges noticeably better than a plain one-step canvas scale. Without it, the tool downscales in halving steps, which already avoids most blur.

Which preset should I use?

Full-HD (1920) fits most screens and e-mail; a 12-megapixel phone photo (4032 x 3024) has about six times more pixels than a Full-HD display (1920 x 1080, 2.07 MP) can even show. Use 4K only for large screens, and the passport preset for 35 x 45 mm biometric prints at 300 dpi (413 x 531 px).

Can I enlarge images too?

You can enter larger dimensions, but upscaling cannot add detail — results get soft. This tool is honest about that: it warns when your target is larger than the original.

Does resizing remove metadata?

Yes. The image is re-encoded, which drops EXIF metadata such as GPS location — good for privacy, but keep the original if you need it.