Weesize

Resize Image in Pixels, CM or MM

Free tool to resize image in pixels, cm, or mm with custom DPI and aspect ratio lock. Free, private, and processed on your device.

1 Choose a JPG, PNG, WebP, or AVIF image to resize.2 Select pixels (px), centimeters (cm), or millimeters (mm) and enter width/height.3 Preview estimated file size and click Download to save your resized image.

About this tool

Change image dimensions in exact pixels or print units (centimeters / millimeters at 300 DPI). Features aspect ratio lock, JPG/PNG output choice, and live file size preview before download. All pixel scaling executes in local browser memory with zero network requests.

Resize Image in Pixels, CM or MM is processed entirely on your device. Your original file remains untouched, and nothing is ever uploaded to a server or saved in the cloud.

  • No upload: image scaling is computed directly on your device GPU and canvas with no data transmission.
  • Speed: processing happens instantly on your device with no upload or download delays.
  • Quality: you can check your file before saving, and the original remains unchanged.
FAQ
What is the difference between resizing pixels and compressing file size?

Resizing changes the physical pixel grid (e.g. 1920×1080 to 800×600 px). Compressing reduces the storage weight in KB/MB while maintaining dimensions. Both help fit online form limits.

How do I convert centimeters or millimeters to pixels?

Select CM or MM mode and enter your dimensions. Weesize automatically calculates pixels using standard 300 DPI print density (or custom DPI).

Will my resized photo be distorted?

No. The "Keep aspect ratio" option is enabled by default, ensuring width and height scale proportionally without stretching.

Can I compress the resized photo to an exact KB target afterward?

Yes. Click "Compress to exact KB size" after downloading to bring the resized image under 20 KB, 50 KB, or 100 KB.

Are my pictures uploaded to resize them?

No. Canvas scaling is performed locally on your device. Your pictures never leave your browser sandbox.

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Last updated 2026-09-27.