Image Resizer & Converter
Resize an image and convert it to PNG, JPG or WebP — all locally in your browser.
How to use
- Choose an image.
- Set a new width or height (ratio stays locked).
- Pick PNG, JPG or WebP, then resize and download.
How the Image Resizer & Converter works
Resizes images to exact dimensions and converts between JPEG, PNG and WebP, all locally in the browser.
The image is drawn onto a canvas at the target dimensions and re-encoded in the chosen format. Locking the aspect ratio computes the second dimension from the first so the image is not distorted.
new height = new width × (original height ÷ original width)
Worked example
A 4000×3000 photo resized to 1200 wide becomes 1200×900, preserving the 4:3 proportions.
Things worth knowing
- Enlarging cannot add detail. Upscaling past the original resolution produces a soft result.
- PNG is lossless and suits screenshots, logos and anything needing transparency. JPEG suits photographs. WebP handles both and is smaller.
- Converting a transparent PNG to JPEG replaces transparency with a solid background, since JPEG has no alpha channel.
Frequently asked questions
Will resizing reduce quality?
Shrinking is clean; enlarging beyond the original size can look soft, as with any image.
Is WebP supported?
Yes — most modern browsers can export WebP, which is smaller than PNG or JPG.
What size should web images be?
No wider than the largest space they occupy, typically 1200–2000 px for full-width images. Serving a 4000 px image into a 800 px slot wastes most of the bytes.