Image DPI Setter
Set the print DPI of a PNG or JPEG without re-encoding.
How to use
- 1 Drop a PNG or JPEG onto the box, or click to choose a file.
- 2 Type a target DPI, or pick a preset such as 300.
- 3 The density metadata is rewritten instantly without touching the pixels.
- 4 Click Download image to save the re-tagged file.
About Image DPI Setter
The Image DPI Setter writes a print resolution into a PNG or JPEG so design and print software reads it at the right physical size.
Drop in a file and the tool stamps the DPI you choose directly into the image metadata, all inside your browser — the file is never uploaded.
DPI (dots per inch) does not change how many pixels an image has; it tells a printer or layout program how large to render those pixels on paper.
A 3000 by 2000 pixel photo at 300 DPI prints at 10 by 6.67 inches, while the same file tagged at 72 DPI is treated as a much larger, lower-resolution image.
Print shops and stock libraries frequently require 300 DPI, and getting a "resolution too low" rejection is often just a metadata flag, not a real pixel problem — this tool fixes exactly that.
Crucially, it edits only the density header: a PNG pHYs chunk (stored as pixels per metre) or a JPEG JFIF density field.
The pixel data is copied through byte for byte, so there is no recompression and zero quality loss — unlike tools that re-export the image.
Common presets (72, 96, 150, 300, 600) are one click away, or type any value.
Everything runs locally and offline once loaded, so it is safe for client artwork and confidential files.
Download the result and your image is ready for print.
FAQ
Does this change the number of pixels?
No. DPI is only a print-size hint in the metadata. The pixel data is left exactly as-is, so there is no upscaling, downscaling or quality loss.
Which formats are supported?
PNG (via the pHYs chunk) and JPEG (via the JFIF density field). Other formats are not modified.
Is my file uploaded?
No. The header bytes are edited entirely in your browser, so the file never leaves your device.