📐 Image Resizer
Resize and crop images with aspect lock and web presets. High-quality resampling, entirely in your browser — no upload.
About the Image Resizer
Most images are published far larger than they are ever displayed, and the fix is the least glamorous optimisation on the web: make the pixels match the layout. This tool resizes and crops in your browser with high-quality resampling — no upload, no queue, no watermark.
Cropping happens first (centred, to the aspect ratio you pick), then scaling. The lock keeps proportions honest by always deriving the partner dimension from the source, so repeated edits never accumulate rounding drift. And because the output goes through the same encoder as the compressor, you can pick WebP output and collect both savings in one pass.
How to use it
- Drop an image, then optionally pick a crop preset — the largest centred region of that shape is used.
- Set dimensions directly, by percentage, or with a fit-within preset (Thumbnail → 4K).
- Choose the output format — keeping the original format is the default.
- Download; the filename records the output size, e.g.
photo-1600x1200.webp.
Frequently Asked Questions
Is my photo uploaded while resizing?
No — resizing happens on a canvas inside your browser. The image never leaves your machine, which you can verify in the network panel. That's also why a 20 MB photo resizes in under a second: there's no round trip.
Does resizing down lose quality?
Scaling down discards pixels by definition, but done well it's the good kind of loss: the tool uses high-quality resampling, and an image displayed at 800px wide genuinely needs no more than ~1600 stored pixels even for high-DPI screens. What you should avoid is scaling UP — the tool allows it, but no resampler can invent detail that was never captured.
What does the aspect-ratio lock actually do?
With the lock on, editing width recalculates height from the original image's proportions (and vice versa), so the image never stretches. The partner value is always derived from the original dimensions rather than the previously-rounded value, so repeated edits don't accumulate rounding drift.
How do the crop presets work?
Each preset (1:1, 4:3, 16:9…) takes the largest centred region of your image with that shape — the same 'crop from the middle' every social platform applies. Cropping happens before resizing, so the dimension fields always describe the final output.
Which output size should I pick for the web?
Content images on most sites display at 700–900 CSS pixels wide, so 1600px wide covers high-DPI screens with room to spare. Thumbnails rarely need more than 480px. Full-screen hero images are the exception — 1920 or 2560px. Pair the resize with WebP output and the byte savings compound.
Why did the file size barely change after resizing?
File size depends on pixel count AND how compressible the content is. If you resized only slightly, or the original was heavily compressed already, the byte saving is proportionally small. Check the size verdict — the tool reports the honest number rather than promising a percentage.