Image Dimension Checker
Select an image to see its width and height in pixels, simplified aspect ratio, megapixels, file size, and type.
Images never leave your browser.
Runs in your browser. Nothing you enter is uploaded.
What it does
Upload any image and this checker reads its real pixel dimensions, then reduces them to a simplified aspect ratio such as 4:5 or 16:9. It also reports megapixels, file size in KB, and the MIME type, which covers most of what a platform upload form will reject a file for.
Use it before posting to confirm a feed image is 1080 x 1350, that a thumbnail is 16:9, or that a banner meets a minimum width. It is also handy when a client sends files named "final.jpg" and you need to know which one is the high-resolution version.
How to use it
- 1
Click Choose an image and select the export you want to verify before uploading.
- 2
Look at the preview to make sure it is the right image.
- 3
Read Width, Height, Aspect ratio, File size, MIME type, and Megapixels in the stats grid.
- 4
Compare the numbers with the platform spec, and resize or crop if they do not match.
What you get
Six values: width and height in px, aspect ratio reduced to whole numbers (for example 4:5), file size in KB, MIME type, and megapixels to two decimals.
When to use it
- Confirm a 4:5 feed image
- Check that an export is 1080 x 1350 and reads 4:5 before scheduling it as an Instagram portrait post.
- Verify thumbnail ratio
- Make sure a YouTube thumbnail comes out as 16:9 and not a pixel off, which would show as an odd ratio.
- Pick the highest-resolution file
- Compare megapixels across several versions of the same photo to find the original.
Example
Input
A portrait export at 1080 x 1350 and a second at 1080 x 1349
Output
1080 x 1350: Aspect ratio 4:5, Megapixels 1.46 1080 x 1349: Aspect ratio 1080:1349, Megapixels 1.46
A one-pixel error stops the ratio from simplifying, which is a quick way to spot an export that is slightly off.
Tips
- If the aspect ratio shows large odd numbers like 131:284, the image is not a standard ratio; phone screenshots often look like this.
- File size is shown in KB. Divide by 1024 to compare with limits given in MB.
- Dimensions come from how the browser decodes the image, so phone photos are reported the way they display, upright.
- Fix a wrong ratio with the image cropper and a too-large file with the image compressor.
Questions
Why does the aspect ratio show numbers like 1080:1349 instead of 4:5?
The ratio is reduced by the greatest common divisor, so it only simplifies to a neat ratio when the dimensions match it exactly. A single pixel off leaves the full numbers.
Does the checker show DPI or print size?
No. It reports pixel dimensions, megapixels, file size, and type. DPI is not read from the file.
Can I check several images at once?
One image at a time. Choosing another file replaces the previous results.
Will the checker read the size of an animated GIF or WebP?
Yes, as long as your browser can display the format. It reports the canvas size of the animation, not each frame separately.