Image Optimization
What Is DPI and How Does It Affect Images?
SnapReduce Technical TeamPublished 2026-09-286 min read
DPI (Dots Per Inch) is one of the most misunderstood concepts in digital imaging. Photographers are frequently told 'web images must be 72 DPI and print must be 300 DPI.' But is that true? Let's dismantle the myths.
Table of Contents
What Does DPI Actually Mean?
DPI stands for Dots Per Inch. It measures printer resolution—the physical density of ink droplets that a printing press deposits onto paper over the span of one linear inch.
DPI vs PPI: What's the Difference?
PPI (Pixels Per Inch) measures digital display density. DPI measures printer ink droplets. In popular software dialogue boxes, the term 'DPI' is commonly used to designate PPI.
Why DPI Is Completely Irrelevant on the Web
Screens display images pixel-for-pixel based on CSS dimensions. A 1000x1000 pixel image saved at 72 DPI and the exact same 1000x1000 image saved at 300 DPI will look 100% identical on every computer monitor and smartphone in the world.
Why DPI Is Critical for Physical Printing
In physical printing, DPI tells the hardware how large to print the image: Print Inches = Pixels / DPI. For an 8x10 inch print at 300 DPI, you need 2400 × 3000 pixels.
Recommended Utility
Open DPI CalculatorCalculate required print DPI
Verify print sizes and required pixel dimensions.
Questions & Answers
How do I make an image 300 DPI?
Make sure your image has enough physical pixels to satisfy (Width in inches × 300) by (Height in inches × 300).
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