PixCheck Image DPI
DPI (dots per inch) determines how an image translates to print. 72 DPI is standard for screens; 300 DPI is the minimum for professional printing. Many print services reject images below their DPI threshold. Pixotter reads the DPI metadata from your image and shows you the print size at various resolutions -- all in your browser.
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Understanding DPI and Image Resolution
DPI (dots per inch) describes how many pixels fit into one inch when an image is printed. A 3000x2000 pixel image at 300 DPI prints at 10x6.67 inches. The same image at 72 DPI would need to print at 41.7x27.8 inches to use every pixel — or would appear pixelated at a smaller size.
The DPI value stored in an image file is metadata — it does not change the actual pixel data. Two identical 3000x2000 images can have different DPI tags (72 vs 300), but they contain exactly the same pixels. What matters for quality is the relationship between pixel dimensions and physical print size.
For web and screen display, DPI is largely irrelevant. Screens display images pixel-for-pixel regardless of the DPI tag. A 1920x1080 image fills a 1920x1080 screen the same way whether it is tagged at 72 DPI or 300 DPI.
For print, DPI matters significantly. Most professional printers require 300 DPI at the final print size. Magazine-quality printing uses 300-350 DPI. Billboards and large format prints can use as low as 100-150 DPI because they are viewed from a distance.
DPI Requirements by Use Case
Different outputs require different DPI minimums:
- Professional print (magazines, brochures, business cards): 300 DPI minimum
- Home printing (photo prints, documents): 150-300 DPI
- Large format (posters, banners): 100-150 DPI
- Billboard/signage (viewed from distance): 50-100 DPI
- Web/screen display: DPI tag is irrelevant — pixel dimensions matter
- Retina/HiDPI screens: 2x pixel dimensions (e.g., 200x200 CSS pixels needs a 400x400 image)
To check if your image has enough DPI for printing, divide the pixel width by the desired print width in inches. If you need to print at 8 inches wide and your image is 2400 pixels wide, that is 2400/8 = 300 DPI — print-ready. If your image is only 800 pixels wide, that is 800/8 = 100 DPI — too low for quality printing.
Related Guides
- How to Check Image DPI — detailed guide with examples
- Resize Images for Print — resize to exact print dimensions
- What Is EXIF Data? — understand image metadata
Frequently Asked Questions
What DPI do I need for printing photos?
For standard photo printing (4x6, 5x7, 8x10), you need 300 DPI at the print size. This means a 4x6 inch print needs at least 1200x1800 pixels. For large format prints like posters (viewed from 2+ feet away), 150-200 DPI is sufficient. For billboards viewed from 50+ feet, even 50-100 DPI works.
Can I increase the DPI of an image?
You can change the DPI metadata tag without affecting the image, but this does not add detail. To truly increase resolution, you need AI upscaling (like Real-ESRGAN) which generates new pixel detail. Simply resampling a 72 DPI image to 300 DPI makes it a smaller physical print at the same quality — it does not make a small image suitable for large prints.
Why does my image show 72 DPI?
72 DPI is the default tag used by most software when saving images for web or screen use. Cameras and phones sometimes set 72 DPI regardless of the actual image quality. This does not mean the image is low quality — a 4000x3000 pixel image at 72 DPI has the same pixel data as one tagged at 300 DPI. Check the pixel dimensions to determine actual quality.
What is the difference between DPI and PPI?
DPI (dots per inch) technically refers to printer output — the number of ink dots per inch. PPI (pixels per inch) refers to screen or image resolution. In practice, these terms are used interchangeably in image editing and web contexts. When someone says "300 DPI image," they usually mean 300 PPI.
Does Pixotter upload my image to check DPI?
No. Pixotter reads the DPI metadata directly in your browser. The image file is processed locally on your device using JavaScript — nothing is uploaded to any server. Your images stay private.
My image has no DPI information — what does that mean?
Some image formats (especially PNG and WebP) do not always include DPI metadata. If no DPI value is found, the image likely defaults to 72 or 96 PPI. The actual print quality depends on the pixel dimensions divided by your desired print size, not the DPI tag.
How It Works
Drag and drop any image file — JPEG, PNG, TIFF, or WebP. Works with photos and design files.
See the embedded DPI value, pixel dimensions, and calculated print size at 72, 150, and 300 DPI.
Instantly see whether your image meets print requirements (300 DPI) or is only suitable for screens (72 DPI).