Image Resizer
Resize images by pixels, percentage or longest side. Keep the aspect ratio and get the perfect size for websites, social media or document attachments.
Inputs are not collected. Usage measurement requires your consent.
Drop files here
Click or drag & drop (PNG / JPG / WebP / GIF)
Done
Image Resizer
Next time, open this tool from My Tools. Only the tool list is saved in this browser, not your inputs or results.
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How to use
- 1
Select image
Choose the image file you want to resize.
- 2
Set the size
Specify the target size by pixels, percentage or longest side.
- 3
Download
Download the resized image.
Features
- Three resize modes: by pixels, percentage or longest side
- Aspect ratio lock recomputes width and height automatically
- Keeps JPG, PNG and WebP formats (with quality control)
- Images stay in your browser and are never uploaded
Use cases
Fit website and blog images to the layout
Downscale oversized images to the display width and cut page weight without visible loss.
Match marketplace and social media specs
Adjust product photos and hero images to the recommended dimensions of each platform.
Meet attachment size rules on forms
Use the longest-side mode to bring scans and ID photos down to the required pixel size.
Details
Resizing changes the pixel dimensions of an image. Common uses include fitting a website layout, matching social media recommended sizes, or meeting attachment limits on forms. Downscaling keeps the visual quality while reducing file size, but upscaling interpolates missing pixels and tends to look blurry.
This tool resizes images entirely in your browser with Canvas and never uploads them to a Tools Hub server. The output keeps the input format (PNG, JPG or WebP; GIF becomes PNG), and JPG / WebP output can be tuned with the quality slider.
"By pixels" takes an explicit width and height; with the aspect lock on, editing one side recomputes the other. "By percentage" scales the whole image (e.g. 50%), and "by longest side" is a quick way to meet rules like "max 1600 px on the long edge" used by social platforms and forms.
FAQ
Can I resize without changing the aspect ratio?
Yes. In "By pixels" mode with the aspect lock on, editing one side recomputes the other. "By percentage" and "by longest side" always preserve the ratio.
Can I upscale images?
Yes, but upscaling interpolates pixels that were never captured, so results look softer or blurrier compared to downscaling.
When does the quality slider apply?
It applies to JPG and WebP output. PNG has no quality parameter, so the slider does not affect it.
Are my images uploaded to a server?
No. All resizing happens locally in your browser and images are never sent to a Tools Hub server.
Related guide
GuideHow to Convert Images: JPEG, PNG, WebP
Compare JPEG, PNG and WebP for transparency, photos and diagrams. Follow the correct settings-before-file workflow, understand HEIC limits and inspect downloaded format, dimensions and byte size.
GuideImage Cropping Guide: Ratios and Sizes Explained
Separate crop aspect ratio from output pixels with a 640×400 example. Learn supported presets, keyboard movement, export formats and the crop-to-resize workflow without promising background removal or unchanged quality.
GuideHow to Resize an Image: Sizes by Use Case
Choose pixel, percentage or longest-edge resizing with exact examples. Verify 640×400 to 320×200, preserve aspect ratio and distinguish pixels, encoded size and print dpi before submitting an image.
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All processing happens in your browser. Your files are never uploaded.
Verified: The three resize modes, aspect locking and error states are covered by browser tests
Did you know?
Most web page columns are 1000 to 2000 px wide. Downsizing a larger image to that width keeps the look almost identical while cutting the file size dramatically.