image tool
Image DPI Checker
Print resolution is often guessed. This tool reads the number the file really stores, names the field it came from, and reports unknown when the file declares nothing at all.
Add files
Drop JPEG images, PNG images, WebP images here, or choose files. Everything stays on this device.
Waiting for files
Accepted input
- JPEG, PNG and WebP images, up to 10 at a time
Limits
- Up to 20 MB per image and 10 images per batch.
- Up to 40 megapixels per image, checked before the pixels are allocated.
- A file without a resolution field is reported as unknown; no value is invented.
Local processing
- Files are read in your browser and are never uploaded to a server.
- Nothing is stored after you close or reload the page.
How to use Image DPI Checker
- Add the images you want to inspect.
- Press Check image DPI.
- Read the table of resolution, its unit and the field it came from.
What it does
- Reads EXIF resolution, JFIF density, PNG pHYs and WebP EXIF blocks.
- Names the exact source of the number so you can judge how trustworthy it is.
- Reports unknown instead of falling back to 72 or 96 DPI.
Limits and things to know
- Most screenshots and design exports store no resolution at all, so the honest answer is unknown.
- A ratio without a unit, such as 2:1, is not DPI and is reported as an aspect ratio.
- Printing software may still rescale the image; stored DPI is only a hint, not a guarantee.
Example
Finding out why a photo printed too small
Add the photo. If the table shows unknown, the file carries no resolution, so the printer picked its own default. If it shows 72 DPI from JFIF, the value came from an old software default rather than a scanner.
Frequently asked questions
My file has no DPI. Is that broken?
No. Screenshots and most web exports simply do not store one. The tool says unknown rather than substituting 72 or 96 DPI.
Does this change the file?
No. Nothing is decoded or re-encoded, so the original bytes are untouched and no output file is produced.
What is dpcm?
Dots per centimetre. The tool converts it to DPI and labels the original unit so you know what the file actually stored.
Runs entirely in your browser on ap98.com. Files are never uploaded.