Image Resizer
Image Resizer — runs in your browser. Inputs are not stored.
Image resizer
Enter values, then press Calculate.
How to use
- In Image, choose a local file. It is not uploaded to a server.
- Set width (px) and height (px). The input cap is 8000px.
- If Keep aspect ratio (width-based) is on, height follows the width.
- Press Resize, check the canvas preview, and save with Download PNG.
- To try another size, change the numbers and press Resize again. Reset clears the selection.
Key concepts
Image resize shrinks or enlarges pixels to match thumbnails, blog bodies, or SNS upload limits. It is redrawn on a browser canvas, so the result is PNG. JPEG or WebP originals also become PNG, which can change size and quality characteristics. Keep-ratio is width-based.
GIF animation is treated like a still frame. EXIF rotation follows browser decoding; if orientation looks wrong, use the rotate tool. Max size follows browser memory and the 8000px cap. Files do not leave the device. With keep-ratio on, only width matters and height follows. JPEG originals becoming PNG can grow in file size. Enlarging does not create sharpness; GIF animation is treated as a still frame.
Example
Upload a 1920×1080 photo, set width 800 with keep-ratio on, and height lands near 450 as a PNG preview. Turn keep-ratio off and force height 600 and the aspect can stretch. Download PNG to get a resized file. A 4000×3000 photo at width 1200 with keep-ratio becomes height 900. Forcing height 500 with ratio off can distort. A portrait reduced to width 400 with keep-ratio gets height from the original ratio.
Related: Image crop · Image compressor
Frequently asked questions
Is there quality loss after image resize?
It is redrawn as PNG, so original format and compression can differ. Enlarging looks soft. Enlarging does not create sharpness. Scaling up a small original looks blurry.
What is the resize maximum?
Input goes up to 8000px. In practice, browser and memory limits also apply. Input above 8000px is capped. If memory is short, go smaller. See the 8000px input cap together with memory limits.
Does GIF animation resize?
Only a still image like the first frame is processed. An animated GIF looks like a still.
Is EXIF rotation applied?
It follows browser decoding. If needed, use an EXIF-remove or rotate tool. Phone rotation EXIF can differ by browser.
Is the chosen photo uploaded to a server?
No. Only a local canvas is used. The file is not uploaded.
Why is keep-ratio width-based?
Height is computed from width. To fix height only, turn keep-ratio off. To match height as the base, turn keep-ratio off and enter both values yourself.
Last reviewed: 2026-09-04