Setting an image to 300 ppi without resampling and believing it is now higher resolution, when the pixel count has not moved.
Resolution and scaling
PPI
Also called pixels per inch, pixel density or ppi vs dpi. Here is what it means, when it changes what you export, and what people get wrong.
Resolution and scalingRuns on your deviceUpdated 10 August 2026
The short answer
PPI, pixels per inch, states how many image pixels are packed into each inch of output. It is a number stored alongside the image that tells a printer or layout program what physical size to use. Changing it on its own does not add, remove or alter a single pixel.
Updated
The short version
PPI at a glance
| Quick fact | Detail |
|---|---|
| Stands for | Pixels per inch |
| What it controls | Intended print size, nothing else |
| Common print target | 300 ppi at normal viewing distance |
| 300 ppi at 8 x 10 inches | 2400 x 3000 px |
| Walmart guidance | 2000 x 2000 px at 300 ppi |
| On screen | Browsers ignore the ppi tag |
Slide the table sideways to see every column.
Why does changing PPI do nothing to your image?
The pixel grid is fixed the moment the file is written. The PPI value is a separate tag that says how densely to lay those pixels down on paper. A 2000 x 2000 px image tagged 300 ppi is asking to be printed 6.67 inches square. Retag the same file at 72 ppi and it asks to be printed 27.8 inches square. The pixels, the file size and the appearance on any screen are identical in both cases.
Only resampling changes the pixel count. In most editors this is a separate tick box in the image size dialogue, and with it turned off the ppi field is pure metadata.
How do you work out the PPI you actually have?
Divide pixels by inches. A 2400 x 3000 px file printed at 8 x 10 inches gives 2400 / 8 = 300 ppi. The same file stretched across 16 x 20 inches gives 150 ppi. Run it the other way to plan a shoot: if you need 300 ppi across 12 inches, you need 3600 pixels on that edge, and no ppi tag will conjure them for you.
Around 300 ppi is the usual target for photographic printing at arm's length. Large format work viewed from a distance is routinely produced at 150 ppi or less without anyone noticing.
How is PPI different from DPI?
PPI counts image pixels per inch. DPI counts the ink dots a printer physically sprays per inch, and a printer typically uses many dots of a few inks to reproduce one pixel's colour, so DPI figures in the low thousands are normal. The two get used interchangeably in everyday speech, including by software menus, but they are not the same measurement and a print shop will read DPI literally.
What do sellers do when a platform asks for 300 ppi?
Walmart Marketplace recommends product images at 2000 x 2000 px at 300 ppi so that zoom works properly. On a web page the browser only sees the 2000 x 2000, and the ppi tag is ignored entirely. The practical approach is to hit the pixel dimensions, set the ppi field to 300 so the file matches the stated requirement, and spend the remaining effort on lighting and background rather than on metadata.
What people get wrong about ppi
Each one is a real failure mode, not a style preference.
Rejecting a supplier photo because it is tagged 72 ppi, without checking whether its pixel dimensions are actually fine.
Saying DPI to a print shop when you mean PPI, since they will read it as ink dots per inch.
Questions people ask
PPI, answered
The follow-up questions people search for once they have the definition.
Does setting 300 ppi improve my image quality?
No. It only declares an intended print size. Quality at 300 ppi depends entirely on having enough pixels: 300 ppi across 10 inches needs 3000 pixels. If the file is 900 px wide, tagging it 300 ppi just means it wants to print three inches wide.
How do I change PPI without changing the pixels?
Open the image size dialogue and turn off resampling before editing the resolution field. With resampling off, changing ppi only rewrites the metadata and adjusts the stated print dimensions. With it on, the software rebuilds the pixel grid and you lose or invent pixels.
What PPI should web images be?
It does not matter. Browsers lay images out by pixel dimensions and CSS, and never read the ppi tag. The old advice about 72 ppi for web dates from early Mac displays and has had no practical effect for decades.
How large can I print a 12 megapixel photo?
A 4000 x 3000 px file prints 13.3 x 10 inches at 300 ppi, or 20 x 15 inches at 200 ppi. Both are the same file. You are choosing how thinly to spread the pixels, and how close the print will be viewed decides how thin is acceptable.
Same cluster
More from the glossary
Neighbouring entries, so every term in the set is one hop from every other.
Product photo
A product photo is an image made to sell a specific item, showing it clearly enough that a buyer can judge what they are getting.
PNG
PNG (Portable Network Graphics) is a lossless image format that stores every pixel exactly as it was saved and supports full alpha transparency.
Profile picture
A profile picture is the small image that represents a person or a business on a platform.
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