Image size checker
Drop one or more images to get a table with their pixel size, file size, real file type, aspect ratio, megapixels and the DPI stored in the file, with the print size at that resolution. The files are read in your browser and never uploaded.
Runs in your browser: nothing you enter is sent anywhere.
How to use it
- Choose or drop one or many images.
- Read the table: file size in KB or MB and in bytes, pixel dimensions, aspect ratio, megapixels, DPI and the print size at that DPI.
- Remove single files with Remove or clear the table with Clear all. On a narrow screen the table scrolls sideways.
How it works
The pixel size comes from the browser’s decoder, with the camera orientation of photos applied. The first megabyte of the file is read for the type signature and the resolution: PNG chunks are scanned for pHYs, JPEG segments for the EXIF resolution tags and the JFIF density. Megapixels are width times height divided by one million, and the print size is pixels divided by DPI times 2.54.
Worked example
A 4032 × 3024 photo is 12.19 megapixels with a 4:3 ratio. If it stores 72 DPI, the print size is about 142 × 107 cm; at 300 DPI it would be 34 × 25.6 cm.
Tips
- Compare several exports at once to see which is smallest in bytes.
- Check the pixel size, not the DPI, before uploading to a site with minimum dimensions.
- Use the resizer or compressor when a file is too large.
Frequently asked questions
Where does the DPI value come from?
From the metadata in the file: the EXIF resolution of a JPEG, otherwise its JFIF density, or the pHYs chunk of a PNG. WebP, GIF and many other files store none, and then the table says not stored. When a JPEG has only an aspect ratio instead of a density, that is not shown as DPI.
Does a higher DPI mean a sharper picture?
No. DPI only says how large the pixels are when printed. A 3000 × 2000 pixel picture is the same picture at 72 or 300 DPI; only its print size changes. For print, divide the pixel size by the DPI: 2480 pixels at 300 DPI is 21 cm.
How is the aspect ratio shown?
As the reduced fraction of width to height, such as 16:9 or 4:3. When the exact fraction is unusual, like 683:384 for 1366 × 768, the closest common ratio within 1 % is shown next to it.
Why can the type differ from the file extension?
The type is taken from the first bytes of the file, so a PNG saved with a .jpg name is reported as PNG. For SVG the type comes from the browser.
Is anything uploaded?
No. The browser reads each file locally, and only the first megabyte is parsed for the type and the resolution. Pixel size is read by decoding the image.