How to Resize an Image to Exact Dimensions
Updated June 2026 · 3 min read
A profile photo that needs to be 400 by 400 pixels. A picture too big for an upload form. A passport photo at an exact size. Resizing an image is an everyday task, and you should not have to upload your photo to a stranger's server to do it. Here is how to resize an image to exact dimensions, or to a ready-made preset, for free and entirely in your browser.
Resize vs crop: which do you need?
Resizing changes the pixel dimensions of the whole image - it scales everything up or down. Cropping cuts away part of the image to change the framing or aspect ratio. If your photo is the right shape but the wrong size, resize. If it is the wrong shape (you need a square from a rectangle), crop first, then resize to the exact pixels.
🔒 Open the image resizer
Exact pixels or presets for Instagram, LinkedIn, YouTube and more. 100% in your browser.
Step by step
- Open the image resizer.
- Drop in your image. It is processed on your device, not uploaded.
- Enter an exact width and height in pixels, or choose a social or document preset.
- Keep the aspect ratio locked to avoid stretching, then download the resized image.
Tips
- Lock the aspect ratio unless you deliberately want to stretch the image. This keeps people and objects looking natural.
- Resize down, not up. Shrinking keeps things sharp; enlarging past the original size looks soft because the extra detail does not exist.
- Resize, then compress. After hitting the right dimensions, run the file through the image compressor to get the smallest possible file.
Limitations to know
You cannot add detail that is not there. Blowing a small image up to a large size will look blurry no matter the tool, because resizing can only work with the pixels it already has. Forcing a new aspect ratio without cropping will distort the image. For best results, start from the largest original you have and size down to what you need.
FAQ
How do I resize an image to exact dimensions?
- Open OpenConvert's image resizer, enter the exact width and height in pixels (or pick a preset), and download the resized image. It runs in your browser with no upload.
What is the difference between resizing and cropping?
- Resizing changes the overall pixel dimensions of the whole image. Cropping cuts away part of the image to change its framing or aspect ratio. You often crop to the right shape, then resize to the exact size.
Does resizing lose quality?
- Making an image smaller keeps it sharp. Enlarging an image beyond its original size stretches the pixels and can look soft, because the detail is not really there to begin with.
Is the resizing private?
- Yes. The image is resized in your browser and never uploaded to a server, so it stays completely private.