Image Info Checker – Size, DPI, Format & EXIF Viewer

Step by step with the Image Info Checker

Add one or more images.
Select an image in the list to show its full report.
Read the sections: file, image, colour, resolution, metadata and camera details.
Copy the report, or download it as a text file.

A real example

An iPhone photo that was renamed holiday.png reports, in part:

Format (from content)   JPEG · image/jpeg
Extension               .png — does not match the content, which is JPEG
Dimensions              4032 × 3024 px
Aspect ratio            4:3 (Standard photo and screen)
Colour profile (ICC)    Display P3
Stored resolution       72 DPI (from EXIF)
Print size at 300 DPI   34.1 cm (13.44 in) × 25.6 cm (10.08 in)
GPS location            28.61394, 77.20902

That explains both why some software refuses the file and why it should not be shared as it is.

What happens to your image

The checker never trusts the file name. It reads the file's opening bytes to identify the real format, then walks that format's own structure: the segments of a JPEG, the chunks of a PNG or WebP, the blocks of a GIF, the header of a BMP or ICO, the directories of a TIFF, or the boxes of an AVIF or HEIC. Dimensions, bit depth, colour model, transparency, animation, compression and resolution all come from there, without decoding the picture.

EXIF data is read from wherever the format keeps it and summarised: camera and lens, exposure, dates, software, and the GPS position if there is one. The ICC colour profile is identified by its own description, such as sRGB or Display P3. The aspect ratio is reduced to its simplest form or, for sizes that do not reduce neatly, matched to the nearest common ratio.

The SHA-256 fingerprint is computed by your browser's built-in cryptography, from the exact bytes of the file. It needs a secure (HTTPS) connection; on other connections that row is left out.

When the Image Info Checker helps

Checking an image meets an upload requirement for file size, dimensions or DPI.
Finding out whether a photo carries a GPS location before sharing it.
Working out why a file named .jpg will not open in some software.
Checking the colour profile of images before they go to print or to the web.

If the result is not what you expected

Stored resolution says Not recorded: Many images carry no DPI value at all, and that is normal: on screens only the pixel count matters. For printing, the print size at 300 DPI is shown instead; set a DPI in an image editor if a form insists on one.
The extension does not match the content: The file was renamed or saved with the wrong extension. Most software looks at the content and opens it anyway, but some upload forms check the extension; convert it with the Image Converter to get a matching one.
The dimensions differ from what another program shows: Some programs report the size after applying the EXIF orientation, which swaps width and height for photos taken in portrait. The checker shows the stored size and the orientation value separately.

Questions about the Image Info Checker

How is the DPI worked out?

It is read from wherever the file stores it: the JFIF header or EXIF data of a JPEG, the pHYs chunk of a PNG, the header of a BMP or the tags of a TIFF. DPI is a note for printing only; it does not change the pixels.

What does the SHA-256 value tell me?

It is a fingerprint of the file's exact bytes. Two files with the same SHA-256 are identical, and any change, even to metadata alone, produces a completely different value.

Can it show where a photo was taken?

If the photo carries GPS data, the checker shows its latitude, longitude and altitude. Remove that data with the Image Metadata Remover before sharing a photo you do not want located.

Is my image uploaded to be checked?

No. The file is read in your browser, and nothing is sent to a server.