Image Resizer
Resize PNG, JPG, WebP and GIF images to exact pixel dimensions with aspect ratio locked. Runs entirely in your browser - no upload, no queue, no watermark.
An image resizer changes an image's pixel dimensions, optionally keeping the aspect ratio locked. This one decodes and redraws the file on a canvas in your browser, so the image is never uploaded to a server.
Runs entirely in your browser · no signup · nothing is uploaded · updated 2026-08-29
or drop it here - the file never leaves your browser
How to use it
- 1.Choose an image or drop it onto the box.
- 2.Enter a width - height follows automatically while the aspect ratio is locked.
- 3.Download the result. The file never leaves your device.
Frequently asked questions
Is my image uploaded anywhere?
No. Decoding and resizing happen on a canvas in your browser using createImageBitmap. There is no network request, which is why this works offline once the page has loaded.
Will resizing lose quality?
Scaling down is close to lossless in perceived quality. Scaling up cannot invent detail - a 200px image enlarged to 800px will look soft no matter which tool you use.
What size should a hero image be?
Match the largest size it actually renders at, then serve it as WebP. A 4000px image displayed at 1200px wastes roughly 90% of its bytes.
Does it keep transparency?
Yes. Output is PNG, which preserves the alpha channel. Use the WebP converter if you want transparency at a smaller file size.
What size should images be for a website?
Match the largest size the image actually renders at, then serve WebP. A full-width hero rarely needs more than 1600px wide; a thumbnail displayed at 300px should not be a 3000px file.
Does resizing an image reduce its file size?
Substantially. File size scales roughly with pixel count, so halving both dimensions cuts the data by about 75%.
What is the difference between resizing and cropping?
Resizing scales the whole image and keeps everything. Cropping cuts pixels away and changes the composition. Resize to fit a layout, crop to change the framing.
Will resizing to a different aspect ratio distort the image?
Yes, if you unlock the ratio. Keep the lock on unless you specifically want the stretch.
The guide behind this tool
2 min readFavicon sizes in 2026: which five files you actually need
Every favicon size browsers and mobile devices request, the HTML that declares them, and why your new icon is still not showing up.
3 min readImage optimization: the four decisions that matter
Format, dimensions, compression level and loading strategy - the four image decisions that decide your LCP, with the numbers to use for each.
2 min readResponsive images with srcset and sizes: a practical guide
How responsive images actually work, why the sizes attribute is the one people omit, and when to use picture instead of srcset.
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