Size Checker
Every number about your image, without opening an editor.
Drag & drop your image here, or click to choose. Everything is read in your browser — nothing is uploaded.
This free image size checker reports the exact pixel dimensions, the simplified aspect ratio, the megapixel count, the file weight and how large the image will print at 72, 150 and 300 dpi. Useful for checking an upload against a platform’s requirements, or working out whether a photo has enough resolution to print. It reads the file in your browser — nothing is uploaded.
Frequently Asked Questions
How do I check an image’s dimensions?
Drop the file onto the box above. The width, height, aspect ratio, megapixels, file size and print dimensions all appear immediately — no upload and no waiting.
How big can I print this photo?
Divide the pixel dimensions by 300 for a sharp photographic print, or by 150 for something viewed at arm’s length such as a poster. The tool does this for you and shows the result in both inches and millimetres at 72, 150 and 300 dpi.
What does the aspect ratio tell me?
It is the shape of the image reduced to its simplest form — 16:9 for widescreen, 4:3 for classic photos, 1:1 for square. Matching the ratio a platform expects is what stops your image being cropped awkwardly on upload.
Are my files uploaded to a server?
No. The file is decoded and re-encoded directly in your browser using JavaScript and WebAssembly, and never leaves your device. That is what makes it safe for private photos, client work and anything confidential, and it is why the tool keeps working with your network disconnected once the page has loaded.
Does this work on Windows, Mac, iPhone and Android?
Yes. It runs in any modern browser on Windows, Mac, Linux, iPhone and Android with nothing to install and no account needed. Chrome, Edge, Firefox and Safari are all supported.