Drag and drop or click to upload a JPG, PNG, or WEBP file. The tool reads the original dimensions and fills them into the width and height fields automatically.
Resize Image Online
Enter any width and height in pixels and resize instantly. Lock the aspect ratio to prevent distortion — free, no signup, no watermark.
How to Resize an Image Online
Type a new width or height in pixels. With the lock icon enabled, the other dimension updates automatically to keep the aspect ratio correct. Unlock to set both dimensions independently.
Click Download to save the resized image as a lossless PNG, ready to upload anywhere.
Why resize images
Web pages load faster when images match the dimensions they are displayed at — sending a 4000px image to fill a 400px slot wastes bandwidth and slows load time. Profile photos, product images, avatars, and thumbnails often have strict pixel requirements. Social platforms like Instagram, LinkedIn, and Twitter each have specific dimension targets for profile pictures, cover images, and post previews. Email clients and CMS platforms frequently have maximum upload dimensions that require resizing before submission.
Aspect ratio lock — when to use it
The aspect ratio is the proportional relationship between an image's width and its height. When you change one dimension without adjusting the other, the image stretches or squishes. The lock icon links the two fields so that changing width automatically recalculates height (and vice versa) to maintain the original proportions. Unlock it only when you specifically need non-proportional dimensions — for example, cropping to a square avatar or a banner with a fixed aspect ratio that differs from the original image.
Resizing vs compressing
Resizing changes the pixel dimensions of an image. Compressing reduces the file size in bytes, usually by discarding data that is not visually noticeable. Both reduce file size, but in different ways. Resizing is better when you need a specific display size. Compression is better when you need a specific file size in KB or MB. For the smallest possible output, resize first to the target display dimensions, then compress.
Does resizing reduce quality?
Scaling an image down reduces pixel count, which is expected — the output is a smaller image. The output PNG is lossless, so no additional compression artefacts are introduced during the resize. Scaling an image up (enlarging) does not recover detail that was not present in the original — the browser interpolates new pixels from existing ones, which can produce softness at large magnifications.
Common image dimensions by use case
Instagram post: 1080 × 1080 px (square), 1080 × 1350 px (portrait). Twitter/X profile photo: 400 × 400 px. LinkedIn cover: 1584 × 396 px. YouTube thumbnail: 1280 × 720 px. Full HD wallpaper: 1920 × 1080 px. Website hero image: typically 1440 – 1920 px wide. Email inline image: usually under 600 px wide for compatibility with most email clients.
Can I resize to an exact file size in KB?
This tool resizes by pixel dimensions, not by file size. If you need an image under a specific KB limit, use the Compress Image tools after resizing, or use Compress JPEG or Compress PNG directly.
What formats does this tool support?
You can upload JPG, JPEG, PNG, and WEBP images. The output is always saved as a PNG, which is lossless and universally supported.