MUTools

Image Resizer

Image Resizer changes the resolution (pixel dimensions) of JPG / PNG / GIF / WebP images. Pick width and height in pixels with "Pixel" mode, or scale by a percentage with "Percent" mode.

Drop a JPG / PNG / GIF / WebP file here

or

JPG / PNG / GIF / WebP supported

All images are processed entirely in your browser and never sent to a server.

You can also paste from the clipboard with Cmd / Ctrl + V.

About Image Resizer

Image Resizer changes the resolution (pixel dimensions) of JPG / PNG / GIF / WebP images. Pick width and height in pixels with "Pixel" mode, or scale by a percentage with "Percent" mode.

Pixel mode offers "Long edge 1920px", "Long edge 1280px", "Long edge 800px", and "Long edge 400px (thumbnail)" presets. Percent mode offers 25 / 50 / 75 / 150 / 200 presets for one-click resizing. Lock the aspect ratio and skip upscaling to avoid surprises.

All images are processed entirely in your browser — nothing is uploaded to a server. Work confidently with confidential assets or personal photos. Runs entirely in your browser.

How to use

  1. Drop a JPG / PNG / GIF / WebP file into the dropzone, or click to pick one.
  2. Choose "Pixel" or "Percent" mode.
  3. In Pixel mode, type width and height directly or pick a long-edge preset (1920px / 1280px / 800px / 400px). In Percent mode, type a percentage or use the 25 / 50 / 75 / 150 / 200 presets.
  4. Toggle "Lock aspect ratio" or "Skip upscaling" as needed.
  5. When the resulting size and file size are shown, click "Download" to save.

Use cases

  • Site operators normalizing photos to around 1920px on the long edge to speed up page loads.
  • Writers and editors resizing blog hero images or social posts to a fixed size.
  • Shrinking images to 400px on the long edge for use as thumbnails.
  • Cutting size in half to dodge Slack or Discord attachment limits.
  • Designers scaling print assets to just the right resolution with percentage input.

Notes

  • Supports JPG / PNG / GIF / WebP, up to 50 MB per file.
  • Processes one file at a time (batch resizing is not supported).
  • Output is capped at 12,000 pixels per side, with percent values constrained to 1–200%.
  • With "Skip upscaling" enabled, target sizes larger than the original keep the original dimensions.
  • GIF input keeps only frame 1 — animation is not preserved.

FAQ

Are images uploaded to a server?
No. Resizing happens entirely in your browser, so confidential assets or personal photos are safe to use here.
Can I resize several images at once?
This tool focuses on single-file resizing. For batch reduction use "Image Compressor", or "WebP Converter" if you also want to change format.
When should I use "Skip upscaling"?
It keeps the original dimensions when a target size would enlarge the image. For example, with a "Long edge 1920px" preset, an 800px source stays at 800px — useful for batch jobs that should never lose quality from upscaling.
How does the aspect ratio behave?
With "Lock aspect ratio" on, entering either width or height auto-fills the other to keep the original ratio. With it off, the image stretches to the input dimensions.
Can I change the output format?
The output format matches the input. Use "WebP Converter" if you need WebP, or combine with other tools for further conversion.