Resize an image to exact dimensions in your browser — no upload.
Processed locally — your image is never uploaded.
How do you resize an image to exact dimensions?
The image is drawn onto a canvas at the new size and re-encoded. With the aspect ratio locked, the missing dimension scales from the original: new height = original height × new width ÷ original width. A 4000 × 3000 photo resized to 800 px wide becomes 800 × 600. Everything runs in your browser, so the photo is never uploaded.
Understanding your result
The image is drawn onto a canvas at the new size and re-encoded. Enlarging beyond the original size will look soft, since pixels are interpolated.
Formula and method
With the aspect ratio locked, the missing dimension is scaled from the original: new height = original height × new width ÷ original width.
Assumptions and limitations
Resizing happens on a canvas in your browser, so very large images depend on your device's available memory. Enlarging beyond the original dimensions interpolates pixels and looks soft, and re-encoding to a lossy format such as JPG can introduce slight quality loss compared with the source file.
Worked example
A 4000 × 3000 photo resized to 800 px wide becomes 800 × 600 with the ratio kept.
How to use this tool
- Choose an image (JPG, PNG or WebP).
- Enter a target width and/or height.
- Keep or stretch the aspect ratio, pick a format and download.
Common mistakes to avoid
- Stretching with the aspect ratio off, which distorts the image.
- Upscaling a small image and expecting extra detail.
About the Image Resizer
Resize any image to the exact dimensions you need and download it. Everything happens in your browser, so your photo is never uploaded.
Who should use this tool
Anyone preparing images for the web, email, avatars or printing who needs a specific size.
Benefits
- Your photo stays on your device because resizing runs entirely in the browser with no upload.
- You set exact pixel dimensions, so the output matches whatever size a form or platform requires.
- Locking the aspect ratio scales the missing dimension automatically and avoids stretched, distorted results.
- The resized file downloads instantly, with no account, watermark or waiting queue.
Practical use cases
- Shrinking a large camera photo to fit an upload size limit on a form or website.
- Creating a profile picture or thumbnail at the exact dimensions a platform expects.
- Preparing lighter images for a web page so it loads faster for visitors.
- Standardising a set of images to one consistent width for a gallery or document.
Frequently asked questions
Is my image uploaded?
No. Resizing runs entirely in your browser and the image never leaves your device.
Which format should I pick?
Use PNG for graphics and transparency, JPG for photos, and WebP for the smallest size with good quality.
Will resizing reduce the quality of my image?
Reducing size stays crisp because pixels are sampled down. Enlarging past the original looks softer, as new pixels are interpolated rather than captured. Saving to a lossy format like JPG can also add minor artefacts, so keep PNG for graphics where sharp edges matter most.