About this tool
About Image Resizer
Resize an image to exact pixel dimensions or scale it by a percentage before uploading it to a website, marketplace, profile, presentation or online form. The tool creates a separate resized copy in your browser, so the original image can remain unchanged.
Resize by pixels or percentage
Use exact pixels when the destination publishes a fixed requirement, such as a 1200 × 630 social preview, a square profile image or a product thumbnail with a standard width. Percentage scaling is more convenient when you simply need the image to be half or twice its current dimensions.
Keep the aspect ratio locked for normal photos, logos and screenshots. Changing width and height independently can stretch faces, circles and text. If the required aspect ratio differs from the source, crop the composition first instead of distorting it.
Resizing versus compressing
Resizing changes the number of pixels. Compression changes how efficiently those pixels are stored. Reducing a 6000-pixel camera photo to the 1200 pixels actually displayed on a page can save more data than repeatedly lowering quality at the original dimensions. If the dimensions are already correct, use Image Compressor instead.
Upscaling deserves extra care. Increasing pixel dimensions cannot create real detail that was absent from the source. A larger result may look softer or show more visible artifacts, so review it at 100% size before publishing.
How to resize an image online
- Add a supported image and note its original width and height.
- Enter the target dimensions or choose a percentage.
- Keep the aspect ratio locked unless intentional stretching is required.
- Preview the result and inspect text, edges, faces and transparent areas.
- Download the resized copy and verify its dimensions in the destination application.
Common image resizing uses
Resize product photos into a consistent catalog grid, prepare hero images for responsive web layouts, reduce camera photos before adding them to a document, or create smaller copies for email and messaging. For several related images, apply the same target dimensions so the final set looks consistent.
Quality, privacy and browser limits
Very large images use substantial memory because the browser must decode the full pixel grid before scaling it. Supported processing runs locally when available, so the image does not need to be uploaded to zer.ai. Keep the original until the resized copy has been checked for orientation, color, transparency and sharpness.
Use Image Cropper when the frame needs changing, Image Compressor when only file size is the problem, or Image Converter when the receiving service requires another format.