Change an image to 300 DPI
For print shops and forms that reject anything that is not 300 DPI. The value is already set.
JPG · PNG · WEBP · HEIC → JPG / PNG
Sent to server: 0 B
Requests made by this tool while processing · how to verify
- Requests that could carry data
- 0
- Engine downloads (code, models)
- 0
- Analytics pings (no file data)
- 0
Counted with the browser's Performance API during the last job. It sees every request the page makes, but not what is inside them, so anything that is not a static download is counted above.
To check yourself: open DevTools → Network, clear the list, run the tool, and inspect each request. None will contain your file. You can also switch to offline after the page loads; tools whose engine is already downloaded keep working.
Preset300 DPI
Drop images here
or paste, or choose files
JPG · PNG · WEBP · HEIC → JPG / PNG
Add one or more JPG or PNG files.
How to make an image 300 DPI
Add the files and download. For JPG and PNG, the tool rewrites the resolution fields (the JFIF density, the EXIF X and Y resolution when present, or the PNG pHYs chunk) and leaves the compressed image data byte for byte as it was. WebP can't store DPI, so it is saved as PNG; iPhone HEIC photos are converted to JPG.
Step by step
- 01Add one or more JPG or PNG files.
- 02300 DPI is already set; type another value if you need one.
- 03Download. The file size barely changes, because the picture is not re-encoded.
DPI does not add detail
DPI is a note in the file that says how many pixels to print per inch. A 1200 × 1800 px photo at 300 DPI prints at 4 × 6 inches; the same file at 72 DPI would print at about 17 × 25 inches. Changing the number does not add or remove pixels, so it cannot make a blurry photo sharp.
- Need a specific print size too? Use Resize image in cm, mm or inches, which changes the pixels.
- Windows shows the value under Properties → Details → Horizontal resolution.
When a form insists on 300 DPI
Some portals and print services read the DPI field and reject files marked 72 or 96. Setting the field to 300 satisfies that check without changing how the photo looks. If they also give pixel dimensions, make sure the photo has at least that many pixels.
Questions
Will changing DPI reduce quality?
No. For JPG and PNG only the header is edited. The compressed image data is untouched, so there is no recompression loss.
Why is the file size almost the same?
Because nothing but a few header bytes changed. A tool that makes the file much bigger or smaller has re-encoded it.
Does it work on many files at once?
Yes. Add a batch and each file gets its own DPI header; download them together as a ZIP.
Is the image uploaded?
No. The header is rewritten in this browser tab. The network meter on the tool stays at 0 B sent.