A cover needs 900×383, an avatar 400×400, or you just want the photo half as large. Enter exact pixels or pick a percentage, and the image resizes instantly — with the aspect ratio locked so nothing stretches.
Downsize freely, upsize carefully
Shrinking loses pixels you will not miss — quality stays effectively unchanged. Enlarging cannot restore detail that was never captured: blown-up images look soft or blurry. When in doubt, resize down from the original rather than up.
How the lock works
With the ratio locked, entering a width computes height as target width ÷ original width × original height. A 4000×3000 photo at width 800 becomes 800×600. Unlock only for exact non-proportional frames (like a cover crop) — and expect some distortion.
Common platform dimensions
Open Graph share image: 1200×630. X/Twitter header: 1500×500. YouTube thumbnail: 1280×720. Instagram square: 1080×1080. US Letter at 300 DPI: 2550×3300. Pair with the Image Compressor after resizing to also shrink the file.