📏 Image Resizer
Resize to exact pixels, aspect ratio locked by default so nothing gets squashed, and download, all without the image leaving your device.
How the image resizer works
The image is redrawn at the target dimensions on a canvas with high-quality resampling enabled, then re-encoded in your chosen format. The aspect-ratio lock recalculates the other dimension as you type, because independent width/height edits are how images get visibly stretched. Downscaling discards pixels (fine); upscaling invents them (soft), the tool tells you which you're doing.
Resolution advice that saves storage: screens are the destination for most images, and a 4000-pixel-wide photo shown in an 800-pixel column wastes 25× the pixels. Resize to roughly the largest display size you need (retina = 2× the CSS size), then compress, the combination routinely cuts files by 90%+.
Frequently asked questions
How do I resize without distorting the image?
Keep the aspect-ratio lock on: set one dimension, and the other follows automatically. Distortion only happens when width and height are changed independently to a different ratio than the original.
Can I make an image bigger?
You can set larger dimensions, but upscaling cannot add detail that was never captured, results look progressively softer. It's acceptable for modest bumps (up to ~1.5×); for serious enlargement you'd want a dedicated AI upscaler.
What size should images be for the web?
Match the largest size they'll display: full-width hero images ~1600-2400px wide, content images ~800-1200px, thumbnails 300-400px. Double the CSS pixel size for sharp rendering on high-DPI ("retina") screens.
Does resizing reduce file size?
Dramatically, file size scales roughly with pixel count, so halving both dimensions cuts pixels (and typically bytes) by ~75%. Resizing down is the single most effective image "compression" step.
Is the image uploaded to resize it?
No, the canvas API resamples on your device. Nothing is transmitted, and there's no watermark or size cap beyond your device's memory.
Related image tools
From the blog
-
Aspect Ratio Explained: What 16:9 Means and How to Resize Without Stretching
Aspect ratio is the width-to-height proportion, 16:9, 4:3, 1:1, independent of pixel size. Resize without stretching and pick the right ratio.
-
JPEG vs PNG vs WebP: Which Image Format to Use (and How to Shrink Files 90%)
JPEG vs PNG vs WebP: JPEG for photos, PNG for screenshots and transparency, WebP for 25-35% smaller web files, plus the resize-then-compress workflow.