Image Resolution Checker
Choose or drop an image to see its exact pixel size, megapixels, aspect ratio and the largest size it will print sharply. The file stays on your device.
No image chosen yet. JPEG, PNG, WebP, AVIF and GIF all work.
| File name | – |
|---|---|
| File type | – |
| File size | – |
| Dimensions | – |
| Megapixels | – |
| Aspect ratio | – |
| Print size at 300 PPI | – |
| Print size at 150 PPI | – |
| Verdict | – |
How to tell if a photo is high resolution
Resolution is the number of pixels across and down. A photo is "high resolution" when it has enough pixels for what you want to do with it:
- Find the pixel size. Use the checker above. Your computer's file information panel usually shows the same width and height in pixels.
- For print, divide by 300. Width ÷ 300 and height ÷ 300 give the largest print in inches at 300 pixels per inch. Our inches to pixels converter works the other way round.
- For screens, compare with the display. To fill a 1920 × 1080 screen without upscaling, the image needs at least that many pixels in the matching shape. See the 1080p and 4K guides for the sizes.
File size (KB or MB) is not resolution. A heavily compressed photo can be small on disk and still have plenty of pixels, and a large PNG can be a small image.
Pixels needed for common uses
| Use | Pixels needed | Megapixels |
|---|---|---|
| 6 × 4 in print at 300 PPI | 1800 × 1200 | 2.2 |
| 10 × 8 in print at 300 PPI | 3000 × 2400 | 7.2 |
| Full HD screen (1080p) | 1920 × 1080 | 2.1 |
| 4K UHD screen | 3840 × 2160 | 8.3 |
Screen sizes come from ITU-R BT.709 and BT.2020. Need to change the shape rather than the size? Use the aspect ratio calculator.
How the checker reads your file
The page creates a temporary local address for the file with URL.createObjectURL(), lets the browser decode it, and reads its natural width and height. Nothing is sent over the network, and the temporary address is released as soon as the size is read.
Frequently asked questions
- How can I tell if a photo is high resolution?
- Look at its pixel dimensions, not its file size. Divide the width and height by 300 to get the largest sharp print in inches: a 3000 × 2400 image prints at 10 × 8 inches at 300 PPI. This checker does that division for you.
- Does this tool upload my image?
- No. Your browser opens the file locally and reads its width and height. The image is never sent to a server, so it works offline once the page has loaded.
- Why does my image show a DPI of 72 elsewhere?
- Many files store a DPI value in their metadata, but it does not change the pixels. What matters for print is the pixel count divided by the print size, which is what this checker reports.
- What counts as high resolution here?
- We call an image high resolution when it can print at least 6 × 4 inches at 300 PPI (1800 × 1200 pixels or more, in either orientation). From 1280 × 720 up to that we call it medium, and below 1280 × 720 low resolution. These thresholds are our own rule of thumb, not a standard.
Sources
- URL.createObjectURL() — creating a local URL for a file without uploading it, MDN Web Docs
- HTMLImageElement: naturalWidth property, MDN Web Docs
- Recommendation ITU-R BT.709 (1920 × 1080 HDTV image format), International Telecommunication Union