Tool
DPI Checker
Upload an image, tell it what size you plan to print at, and it works out the exact DPI -- along with whether that's sharp enough for the job. Nothing is uploaded to a server; the calculation happens entirely in your browser.
Drop an image here, or click to choose one
JPG, PNG, WEBP, GIF · stays on your device
Upload an image and enter a print size to see its DPI here.
What is DPI?
DPI, dots per inch, measures how densely an image's pixels are packed onto a printed page. It's the print equivalent of pixel density on a screen: the same file printed small has a high DPI, and printed large has a low one, because the same fixed number of pixels is being spread over more or less paper.
This is why DPI isn't really a property of an image file on its own. It only exists once you pair a pixel count with a physical print size, which is exactly what the calculator above does.
How to check DPI of an image online
To check the DPI of an image for print, upload the file above, enter the finished size you want, and read the effective DPI result. This is more useful than looking at file properties, because many images contain an old metadata value such as 72 DPI or 96 DPI even when the actual pixel dimensions are large enough for print.
- Upload your JPG, PNG, WEBP, or GIF image.
- Enter the exact width and height you want to print.
- Use inches for US print sizes or centimetres for metric jobs.
- Check the effective DPI and the recommendation shown by the tool.
For close-viewed work, aim for 300 DPI. For posters, signs, and trade-show graphics viewed from farther away, 150 DPI is often acceptable. If the result is below 100 DPI, the print will usually look soft unless it is very large and viewed from a distance.
When do you need 300 DPI?
300 DPI is the conventional benchmark for close-viewing print work: business cards, magazines, product packaging, and photo prints. At normal reading distance, the eye can resolve detail fine enough that anything much lower can start to look soft.
For large-format printing, the math changes. Banners, billboards, and event signage are viewed from several feet or more away, so printers commonly work at 100 to 150 DPI for these without any visible loss of quality, because the viewing distance does the smoothing that resolution would otherwise need to do.
Recommended image size for common prints
| Print size | Best at 300 DPI | Usable at 150 DPI |
|---|---|---|
| 4 x 6 photo | 1200 x 1800 px | 600 x 900 px |
| 5 x 7 photo | 1500 x 2100 px | 750 x 1050 px |
| 8 x 10 photo | 2400 x 3000 px | 1200 x 1500 px |
| US Letter | 2550 x 3300 px | 1275 x 1650 px |
| A4 | 2480 x 3508 px | 1240 x 1754 px |
| 18 x 24 poster | 5400 x 7200 px | 2700 x 3600 px |
These examples help answer searches like “how to check DPI of image online free” and “what size image do I need for an 8x10 print” with a practical number instead of a vague quality rule.
Common printing mistakes
- 01Pulling an image straight from a website. Web images are usually optimised down to a few hundred pixels wide, which is far short of what most print sizes need.
- 02Trusting the DPI number saved in the file's metadata. That number can be wrong or leftover from a previous edit -- the pixel dimensions are what actually matter.
- 03Upscaling a low-resolution image and expecting it to look sharp. Resampling adds pixels, not detail.
- 04Designing without checking the final print size first. A 300 DPI image at 4x6 inches becomes a 100 DPI image at 12x18 inches.
FAQs
What is DPI, exactly?
DPI stands for dots per inch, and it describes how many pixels of your image are packed into each inch of the printed page. It's a measure of density, not a fixed property of the file -- the same image can be 300 DPI at a small size and 72 DPI if you stretch it across a poster.
When do I actually need 300 DPI?
300 DPI is the standard target for anything viewed up close, like business cards, brochures, and photo prints. Large-format pieces such as banners or posters are usually viewed from a few feet away, so 150 DPI, or sometimes even less, still looks sharp.
My image is 72 DPI. Is that always too low?
Not necessarily. A 72 DPI label on a file is often just leftover metadata from when it was saved for a screen. What actually matters is the pixel count relative to the size you intend to print. A 3000 x 2000 pixel photo can print sharp at 8x10 inches regardless of the DPI number stored in the file, because that resolves to 300+ DPI at that size.
Can I increase an image's DPI without losing quality?
You can resample an image to add pixels, but software can only estimate what those new pixels should look like -- it can't recover detail that was never captured. For genuinely low-resolution source images, the more reliable fix is printing smaller or sourcing a higher-resolution original.
Does this tool upload my photo anywhere?
No. The DPI checker reads the image's pixel dimensions directly in your browser using JavaScript. The file never leaves your device or touches a server.