Image Info & Dimensions Checker
Read an image’s format, pixel size, bit depth, alpha and animation from its header — no upload, no decoding — plus megapixels, aspect ratio and print size.
Everything the file header says about an image, whether its extension is honest, and how large it can be printed at the density you choose.
Example: A 1920 × 1080 PNG is 2.07 megapixels, 16:9 landscape, 8-bit RGB; at 300 ppi it prints 16.3 × 9.1 cm, and printed 20 cm wide it lands at 244 ppi.
The first few bytes
say most of it.
What is read from the file, what is calculated from it, and what is not looked at.
Reading the header
Every image container starts with a signature and a header that states the pixel size: PNG's IHDR chunk (with bit depth and colour type), JPEG's start-of-frame marker (components, baseline or progressive), WebP's VP8, VP8L or VP8X chunk (lossy, lossless, alpha, animation), GIF's logical screen descriptor, BMP's info header and ICO's directory. The page reads only those bytes in your browser — the file is never uploaded and never decoded — so a 50 MB photo is inspected as fast as a thumbnail. An SVG's intrinsic size comes from its width/ height attributes or its viewBox.
Derived figures
Megapixels are width × height ÷ 10⁶; the aspect ratio is reduced by the greatest common divisor and matched to the common names (16:9, 4:3, 3:2…) within 1 %. Bytes per pixel is the file size over the pixel count — a rough measure of how compressed the file is. Printing: pixels per inch at a chosen print width is width ÷ (cm ÷ 2.54), and the largest print at a target density is width ÷ ppi. 300 ppi is prefilled only because you can change it; it is not a recommendation.
Not read
EXIF and other metadata (camera, GPS, orientation tag, embedded DPI) are not parsed, so the size shown is the stored pixel grid before any rotation tag. AVIF and HEIC sizes live in nested boxes and are not read here; open the file in the Image Converter to get them after decoding. Nothing leaves the browser; the same four anonymous usage counts as the rest of the site apply.
SOURCES
- PNG (ISO/IEC 15948) IHDR; JPEG (ITU-T T.81) SOF markers; WebP container (RIFF, VP8/VP8L/VP8X); GIF89a; BMP BITMAPINFOHEADER; ICO directory — header layouts as published, read locally
Last reviewed 20 September 2026. How results are checked: How we verify.