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DPI Converter

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This free DPI converter changes the DPI recorded in a JPG or PNG without re-encoding the picture. It also tells you the thing most tools will not: whether your image actually has enough pixels for the size you are printing.

Drop a JPG or PNG to read and change its DPI

The picture itself is never re-encoded. Nothing is uploaded.

Runs entirely in your browser. Your images are never uploaded to a server.

How it works

  1. Drop a JPG or PNG onto the box above. The tool reads the DPI currently stored in the file, and tells you if there is none.
  2. Pick a DPI, or type one. 300 is what most printers ask for.
  3. Choose the size you are printing at, and the tool shows the real resolution your pixels give at that size, which is the number that decides how the print looks.
  4. Download. Only the header changes: the image data is byte for byte what you dropped in.

Common use cases

Frequently asked questions

Does changing the DPI improve image quality?
No, and this is the single most important thing to understand about DPI. The number is a note in the file header saying how large the image should print. It does not add pixels, sharpen anything, or change how the picture looks on a screen. A 600 by 400 photo set to 300 DPI is exactly the same 600 by 400 photo, and it will print two inches wide. Any tool that implies otherwise is selling you a number.
How do I make an image 300 DPI?
Drop it above and press 300. That writes 300 into the file, which is genuinely what a printer means when they ask for a 300 DPI file. But it is worth checking the panel beside it, because the number only matters alongside the size: 300 DPI on an image with 600 pixels across means a two inch print. If you need it larger than that, you need more pixels, not a different number.
Can I increase the DPI of an image to make it bigger?
Not usefully. Increasing DPI makes the file claim a smaller print size, not a bigger one, because you are packing the same pixels more densely. What people usually want is more pixels, which means enlarging the image itself. That can be done, but it invents detail that was never captured, and it always softens. Our image resizer will do it if you need it.
Why does my image show 72 DPI?
Because 72 is what most software assumes when a file records nothing, a convention left over from early Mac screens. It is not a flaw in your image and it says nothing about quality. A file with no DPI and a file marked 72 DPI usually contain identical pixels.
Why do two programs show different DPI for the same file?
Because a JPG can store the value in two places, its JFIF header and its EXIF block, and nothing forces them to agree. Programs pick whichever they were written to trust. If your file does this, the tool above says so and writes the same value to both when you save.
Which formats can store a DPI?
JPG and PNG, which is why those are the two this accepts. WebP, AVIF, GIF and HEIC have nowhere sensible to record one, so there is nothing to change in those files. If you need a DPI tag, convert to JPG or PNG first.
Will this recompress my photo?
No. The file is edited in place at the container level, the way changing a filename does not retype a document. The compressed image data is never decoded, so the picture that comes out is identical to the one that went in. Tools that redraw the image to change the header quietly degrade it a little every time.
Are my images uploaded to a server?
No. The file is read and rewritten in your own browser, and never leaves your device.

Related tools

Understand what this does

Plain explanations of what is happening to your file, and what it costs you.

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