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Image Resizer

Change an image's size in pixels, as a percentage, or in centimetres at a DPI you choose.

Drag and drop an image here

JPG, PNG, WebP, AVIF, HEIC, GIF or BMP · one file · up to 50 MB

Your image stays on this device and is never uploaded.

How to use the Image Resizer

  1. Choose an image, or drag it onto the drop area.
  2. Pick how to resize: pixels, percentage, or centimetres with a DPI.
  3. Enter the new size. Leave “Lock aspect ratio” on to keep the original proportions.
  4. Check the comparison of the original and new dimensions, and choose a format.
  5. Press Resize image, then download the file. The result shows its real size and dimensions.

About this tool

Resizing changes how many pixels an image has. Making an image smaller discards detail; making it larger cannot add detail that was never captured, so enlarged images look softer. This tool halves large images in steps when reducing them so fine detail holds up better than a single jump.

Centimetres only describe a print size once you decide how many pixels fit in each inch. At 300 DPI, 10 cm is about 1181 pixels; at 150 DPI it is about 591. The tool works out the pixel size as centimetres ÷ 2.54 × DPI. The saved file does not store a DPI value, so the size on paper still depends on the printer or software, and changing pixel dimensions alone does not guarantee a particular printed size.

Locking the aspect ratio keeps the picture's proportions by updating one side when you change the other. Unlock it only when you want to stretch or squash the picture. The tool warns you when the new proportions differ from the original.

Output formats are the ones your browser can really save. JPG and WebP are lossy and have a quality setting; PNG is lossless and usually larger for photographs. If a format is missing from the list, your browser cannot save it. Very large outputs are refused (each side up to 12,000 pixels and 50 megapixels) because browsers and phones can run out of memory.

Practical uses

  • Making a photo fit a form or website that states a width and height in pixels.
  • Shrinking a large camera photo before emailing it.
  • Preparing an image for print at a stated size in centimetres and DPI.

Tips for better results

  • Start from the largest original you have, and avoid resizing the same file repeatedly.
  • For a target file size in KB or MB, use the Image Compressor, which measures the real size as it goes.
  • Use JPG or WebP for photographs and PNG for screenshots, logos and graphics with sharp edges.

Frequently asked questions

Will resizing reduce the file size?

Usually, if you make the picture smaller, but not always. A PNG can be bigger than the original JPG, and a high quality setting can keep a file large. The result panel shows the real size of the file you get.

Does the file remember the DPI I typed?

No. DPI is used only to work out the pixel size from centimetres. The downloaded file does not carry a DPI value, so printing software may assume its own.

Why was my size refused?

Sizes are limited to 12,000 pixels per side and 50 megapixels in total, because larger canvases often fail in browsers. Choose a smaller size.

Is my image uploaded?

No. The picture is processed in your browser and never leaves your device.

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Privacy

Your image is processed in your browser on your own device. It is not uploaded to Paul Digital or any other server, and nothing is stored once you close the page.