Resize an image to exact pixels with optional aspect-ratio lock, then download. Runs in your browser.
No. The resize happens entirely in your browser using a canvas; the image never leaves your device.
Yes. With ‘Lock aspect’ on, changing the width updates the height automatically (and vice-versa) so the image isn't stretched.
PNG, which is lossless. For smaller files from photos, you can re-save the result as JPG/WebP with the image compressor tool.