Resize Image Online
Change image width and height in pixels, preview the result and download a resized JPG, PNG or WebP file. Everything happens locally in your browser, so your image is not uploaded.
Change image dimensions in pixels
Upload an image, set the target width and height, keep the aspect ratio locked if needed, then export the resized file.
Original / Upload
Result / Output
What does resizing an image mean?
Resizing an image means changing its pixel dimensions. A photo that is 4000 pixels wide and 3000 pixels tall contains more pixels than a version resized to 1200 by 900 pixels. The image still shows the same scene, but the file has fewer or more pixels to describe it. Width and height are the practical dimensions used by websites, email clients, documentation tools, marketplaces and social platforms.
Resolution is often confused with dimensions. Pixel dimensions describe how many pixels the image has. Print resolution, usually measured in DPI or PPI, describes how densely those pixels are placed on paper. For online work, the width and height in pixels usually matter most. Resizing is also different from cropping: resizing scales the whole image, while cropping cuts away part of the image to change framing or aspect ratio.
When should you resize an image?
Resize images when the original is larger than the place where it will be used. A blog post may need a 1200 pixel hero image instead of a full camera export. A product marketplace may require a fixed square size. A presentation may need smaller screenshots so the file stays easy to share. Email newsletters, documentation pages, support articles and internal wikis also benefit from predictable image dimensions.
Websites and blogs
Match layout widths and avoid oversized media assets.
Social media
Prepare graphics for platform-specific pixel sizes.
Email and docs
Keep screenshots readable without bloating the file.
Resize vs compress
Resizing changes the number of pixels. Compressing changes how the file stores those pixels. If a 3000 by 2000 image is resized to 1200 by 800, the result has fewer pixels. If that 1200 by 800 file is compressed, the dimensions stay the same, but the encoder tries to reduce file size by storing visual information more efficiently. Both can make files lighter, but they solve different problems.
Use resizing when the image is physically too large for a layout, upload requirement or workflow. Use compression when the image has the right dimensions but the file size is still too high. JPEG and WebP compression can be lossy, while PNG is often better for graphics, screenshots and transparency.
Does resizing reduce quality?
Resizing always asks the browser to recalculate pixels. When you shrink an image, many pixels are combined into fewer pixels. That usually looks good if the target size is reasonable. When you enlarge an image, the browser must invent new pixels between the existing ones through interpolation. That can make blur, softness and edge artifacts more visible, because there is no new detail in the original file.
This tool uses browser canvas smoothing with a high-quality setting where available. It preserves transparency when exporting to PNG or WebP. JPEG does not support transparency, so transparent areas are placed on white when JPEG output is selected.
Private browser-based resizing
The image you choose is decoded and resized in your browser. No upload occurs, no external image API is called and the file is not sent to MetricLab servers. The original preview and resized result are created from temporary local object URLs that exist only in your current browser session.
This local workflow is useful for sensitive screenshots, internal documentation, draft product images and client files that should not leave your device just to change dimensions.
Tips for best results
Start from the original
Resize from the highest-quality source instead of repeatedly resizing an already resized copy.
Preserve aspect ratio
Keep the ratio locked unless you intentionally need a stretched image for a fixed placeholder.
Choose the right format
Use JPEG for photos, PNG for transparency or screenshots, and WebP when you want modern web-friendly output.
FAQ
Is this tool free?
Yes. It is free, online and does not require a login.
Are my images uploaded?
No. Images are processed locally in your browser with Canvas and browser image decoding APIs.
Can I resize PNG files?
Yes. PNG is supported, including transparent PNG output when you keep PNG as the export format.
Can I resize JPEG images?
Yes. Upload a JPG or JPEG image, set dimensions and download the resized result.
Does resizing reduce quality?
Shrinking usually works well. Enlarging can reduce visible quality because the browser must estimate new pixels.
What's the difference between resizing and cropping?
Resizing scales the whole image. Cropping removes part of the image to change framing.
Can I resize images for social media?
Yes. Enter the pixel dimensions recommended by the platform and download the resized file.
Which image formats are supported?
JPG, PNG and WebP are supported in modern browsers.