AZ Tools

Image Aspect Ratio Detector

Image

Reads the natural width and height with the browser's Image API, divides them by their GCD to give a clean integer ratio (`1920×1080` → `16:9`), and matches the result against the most common screen, social, and camera ratios. No upload — the file is decoded locally and discarded when you clear it.

Everything runs in your browser — the file never leaves your device.

How to use

  1. Drop an image or click to pick one.
  2. Read the ratio in its simplest form, the decimal version (handy for CSS `aspect-ratio: 1.778 / 1`), and the megapixel count.
  3. Compare to the closest preset to know if you're effectively on 16:9, 4:3, etc.

Frequently asked questions

Why does my 4032×3024 phone photo come out as 4:3?
4032 ÷ 1008 and 3024 ÷ 1008 both equal a small integer (4 and 3 respectively) — the GCD is 1008. That's standard for 12 MP phone sensors, which are physically 4:3 chips.
What does "closest preset" mean?
We score the image against a handful of named ratios (1:1, 4:3, 16:9, 21:9, 9:16, …) and pick whichever is nearest in absolute ratio difference. The percentage tells you how close — under 1% means it's effectively that preset; 5% means you're between two named ratios.
Does it run on huge images?
Yes — the browser decodes the image to read dimensions and then discards the decoded pixels. Even 50 MP files measure instantly. Only metadata stays in memory.

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