Size Checker
Check an image's dimensions, file size, and format. Upload an image to instantly see its width, height, aspect ratio, and more.
Click to upload an image
Your file is processed entirely in your browser
Recommended Settings
Pro Tips
- •Dimensions are read from the actual decoded image, not just the file's metadata, so they're always accurate
- •Aspect ratio is simplified to its smallest whole-number form, like 16:9 or 4:3
- •Megapixels are calculated as width × height, which is the same measure used to describe camera and phone sensor resolutions
- •The whole file is processed locally in your browser - nothing is uploaded anywhere
Most Popular
Most users check this before uploading a photo to confirm it meets a platform's size or resolution requirements
When to Use This Tool
Confirm an image meets a website or platform's minimum or maximum dimension requirements before uploading.
Quickly see whether an image matches a standard aspect ratio like 16:9, 4:3, or 1:1.
Check how large an image file is before attaching it to an email or adding it to a webpage.
Check an image's megapixel count to estimate whether it has enough resolution for a print size.
How It Works
Read the uploaded file's raw size in bytes and its declared MIME type
Decode the image using the browser's native image support to read its true pixel dimensions
Calculate the aspect ratio using the greatest common divisor of the width and height
Display all of the information together alongside a preview of the image
100% Private
Files never leave your device. All processing happens locally in your browser.
Lightning Fast
Powered by Browser native File and Image APIs for optimal performance on modern browsers.
Open Source
Built with verified, open-source libraries. Fully transparent.
Frequently Asked Questions
Is the file size the same as what I'll see on my computer?
Yes. The file size shown is the exact byte size of the uploaded file, the same value your operating system would show in a file properties dialog.
Why does the aspect ratio show unusual numbers sometimes?
The aspect ratio is simplified using the greatest common divisor of the width and height. Unusual dimensions that don't match a common ratio will show as their own simplified fraction rather than a familiar ratio like 16:9.
Is my image uploaded to a server?
No. The entire process runs locally in your browser using the File and Image APIs. Your image never leaves your device.
Does this tool modify my image?
No. This tool only reads and displays information - it doesn't alter, compress, or resave your image in any way.
What does megapixels tell me?
Megapixels represent the total pixel count (width × height, divided by one million). It's a common way to describe resolution, especially in the context of cameras and printing.