Image DPI Checker
Find out the DPI recorded in an image and what it means for printing. See the print size at the stored resolution and at 300 DPI, and set a new DPI value for print shops or forms that require one, without changing image quality.
- Files stay on your device
- No sign-up
- Free to use
| File | Pixels | DPI | Stored in | Print size at this DPI | Max size at 300 DPI |
|---|
Change the DPI value
Rewrites only the resolution value in the file header. The pixels are not changed or recompressed, so quality stays exactly the same. Supported for JPG, PNG and BMP.
How to use Image DPI Checker
- Drop one or more images onto the upload area.
- Read the table: pixel dimensions, the stored DPI and where it is stored, the print size it implies, and the largest size that prints at 300 DPI.
- To change the DPI, type a value or choose 72, 96, 150, 300 or 600.
- Select Set DPI and download. Only the header changes; the pixels stay identical.
Image DPI Checker features
Reads the real header
Looks inside the file at JPEG JFIF and EXIF fields, the PNG pHYs chunk, and TIFF and BMP headers, rather than guessing.
Print size calculator
Shows the physical size in inches and centimetres at the stored DPI and at the 300 DPI print standard.
Lossless DPI change
Rewrites only the resolution value, so JPGs are not recompressed and no detail is lost.
Keeps fields consistent
When a JPEG stores DPI in both JFIF and EXIF, both are updated so every program reads the same value.
Batch checking
Check and update up to 100 images at once.
Local processing
Files never leave your device.
When to use Image DPI Checker
- Meeting a print shop or publisher requirement for 300 DPI files.
- Checking whether a photo is large enough for a poster, canvas or photo book.
- Fixing passport and visa application forms that reject 72 DPI images.
- Making Word and InDesign place images at the intended physical size.
- Auditing a folder of scans to confirm the scanner resolution.
Image DPI Checker FAQ
Does changing DPI improve image quality?
No. DPI in a file is only an instruction about how large to print the pixels. Changing it from 72 to 300 makes the same pixels print smaller and more densely; it does not add detail. To print larger with the same density, you need more pixels.
My image says 72 DPI. Is it low quality?
Not necessarily. 72 is a common default that many cameras and programs write without meaning anything. What matters for printing is the number of pixels: a 3000 × 2000 image at 72 DPI can be set to 300 DPI and still print at 10 × 6.7 inches.
What is the difference between DPI and PPI?
Strictly, PPI (pixels per inch) describes images and DPI (dots per inch) describes printers. In everyday use, and in most software, DPI is used for both, and the value stored in an image file is technically PPI.
Why does my image show “Not stored”?
Many images, especially screenshots, web images and WebP files, simply do not contain a resolution field. Programs then assume a default, usually 72 or 96 DPI. You can add a value to JPG, PNG and BMP files here.
What DPI do I need?
For photos viewed at arm’s length, 300 DPI is the usual standard. Large posters viewed from a distance look fine at 150 DPI or lower. On-screen use ignores DPI entirely.
Pixels, inches and the DPI number
A digital image has no physical size of its own. It is a grid of pixels, and the DPI value tells software how many of those pixels to place in each inch when printing or laying out a document. An image 2400 pixels wide is 8 inches wide at 300 DPI, 16 inches at 150 DPI and 33 inches at 72 DPI. Changing the DPI therefore changes the intended print size, not the image content.
Because the number is only metadata, it can be stored in several places, and different programs read different ones. JPEG files may record it in the JFIF header, in EXIF data, or both, and the two can disagree. PNG files use a pHYs chunk measured in pixels per metre. Many images contain no value at all. This checker reports exactly which field it found, which helps explain why two programs show different numbers.
Changing the DPI field without resampling is the right operation when a printer, publisher or form simply requires a particular number and the image has enough pixels. Image editors often offer a “resample” checkbox when changing resolution; with resampling off, they do the same as this tool. With resampling on, they invent or discard pixels, which changes quality.
To check whether an image is truly suitable for a print size, look at the “Max size at 300 DPI” column. If it is smaller than the print you want, the image will look soft when printed at full quality, and a higher-resolution original is the only real fix.