Drop an image to see its DPI (dots per inch), its pixel size, and how large it prints. The checker reads every place a file can store resolution: the JFIF header, EXIF data, Photoshop's resolution setting, and XMP in JPEGs, the pHYs chunk in PNGs, TIFF tags, and BMP headers. It tells you when they disagree, and shows whether the image is sharp enough for common print sizes from 4 x 6 to 24 x 36. You can also change the DPI to 300 or any other value without resampling or recompressing, so the pixels stay exactly the same. Check and convert a whole batch at once. Nothing is uploaded.
How to check the DPI of an image
- Drop one or more images, click Choose images, or paste with Ctrl+V.
- Each file shows its DPI next to its name. Click a file to see the details: where the DPI is stored, the print size, and the print quality at standard sizes.
- To change the DPI, pick a value such as 300, or choose Set print width and enter the width you want in inches or centimeters.
- Click Download for one file, or Apply to all to get every image in a ZIP.
Change DPI without losing quality
Many apps "change DPI" by resizing the image, which adds or throws away pixels, or by re-saving it, which recompresses a JPEG and loses detail. This tool edits only the resolution values stored in the file and leaves the image data untouched, so the result is identical pixel for pixel. That's what print-on-demand sites, Etsy printables, Amazon KDP, and print shops are asking for when they require "300 DPI": a file that's labeled 300 DPI and has enough pixels to back it up.
Changing the DPI only changes the print size the file suggests. A 3000 x 2400 pixel image prints at 10 x 8 inches at 300 DPI and 41.7 x 33.3 inches at 72 DPI, but it's the same image with the same detail either way. If the image doesn't have enough pixels for the size you need, a higher DPI number won't make it sharper. Check the print quality table instead.
How many pixels you need
| Print size | At 300 DPI | At 200 DPI | At 150 DPI |
|---|---|---|---|
| 4 x 6 in | 1200 x 1800 | 800 x 1200 | 600 x 900 |
| 5 x 7 in | 1500 x 2100 | 1000 x 1400 | 750 x 1050 |
| 8 x 10 in | 2400 x 3000 | 1600 x 2000 | 1200 x 1500 |
| 8.5 x 11 in (Letter) | 2550 x 3300 | 1700 x 2200 | 1275 x 1650 |
| A4 (210 x 297 mm) | 2480 x 3508 | 1654 x 2339 | 1240 x 1754 |
| 11 x 14 in | 3300 x 4200 | 2200 x 2800 | 1650 x 2100 |
| 16 x 20 in | 4800 x 6000 | 3200 x 4000 | 2400 x 3000 |
| 18 x 24 in | 5400 x 7200 | 3600 x 4800 | 2700 x 3600 |
| 24 x 36 in | 7200 x 10800 | 4800 x 7200 | 3600 x 5400 |
300 DPI is the standard for photos and anything viewed up close. 200 to 240 DPI still looks sharp for most prints, and 150 DPI is fine for posters and banners seen from a few feet away.
Why different apps show different DPI
A JPEG can store its resolution in up to four places, and apps don't agree on which one to read. Photoshop prefers its own resolution setting, many apps read the EXIF value, and others read the JFIF header. If a camera or editor wrote 72 in one place and 300 in another, two apps will show two different numbers. The checker lists every value it finds and flags any disagreement. When you set a new DPI, all of them are updated together, and a JFIF header is added if the file doesn't have one, so every app reports the same number.
PNG stores resolution in pixels per meter, so 300 DPI is saved as 11,811 pixels per meter and may appear as 299.99 in some apps. That's normal and prints identically.
Frequently asked questions
How do I check if an image is 300 DPI?
Drop it on the checker. The DPI saved in the file appears next to the file name and at the top of the details. Also check the pixel size: for a print to really be 300 DPI, the pixels divided by the print size in inches should be at least 300, which the print quality table shows for you.
How do I change an image to 300 DPI?
Add the image, choose 300 under Change DPI, and click Download. JPG, PNG, TIFF, and BMP files are updated without re-saving the image, so there's no quality loss. WebP and GIF can't store DPI, so the tool offers a lossless PNG copy instead.
Does changing DPI reduce quality?
Not here. Only the resolution label is changed, and the image data is copied byte for byte. Tools that resample the image to a new pixel size do change quality, which is a different operation.
Why does my image say 72 DPI?
72 is a common default written by cameras, phones, screenshot tools, and web export features, or assumed when no DPI is saved at all. It says nothing about quality. A 4000-pixel-wide photo at 72 DPI has exactly the same detail as at 300 DPI; it just suggests a larger print size.
What DPI do Etsy printables and Amazon KDP need?
Most print-on-demand services, Etsy digital download buyers, and Amazon KDP expect 300 DPI at the final print size. For example, an 8 x 10 inch printable should be 2400 x 3000 pixels and saved at 300 DPI. Use Set print width to apply the right DPI for a given width.
Are my images uploaded?
No. Files are read and edited in your browser and never sent to a server.