Image DPI Metadata Editor

How to use the image dpi metadata editor

1. Choose a PNG or JPG, up to 25 MB. Other formats are not accepted.
2. Check the resolution stored now, where it is stored, and the pixel size of the picture.
3. Enter the new DPI or use a button for 72, 96, 150, 300 or 600. The page shows the print size that DPI gives.
4. Save the file with the new resolution. The name ends with the DPI, such as photo-300dpi.jpg.

What changes in the file

DPI is a label that tells a print program or word processor how large to make a picture. It does not add or remove pixels and does not change quality. A picture of 4,800 by 3,600 pixels prints 16 by 12 inches at 300 DPI, 32 by 24 inches at 150 DPI and 66.7 by 50 inches at 72 DPI. Only the small header record that holds the label is rewritten.

A PNG stores its resolution in a pHYs chunk as pixels per meter, so 300 DPI is written as 11,811 pixels per meter and reads back as 299.9994 in some programs. The chunk is placed right after the image header, and an existing one is replaced. The chunk has a checksum, which the tool computes. A JPEG stores it in the JFIF header as whole dots per inch. If a JPEG has no JFIF header, one is added at the start, and if it carries an EXIF resolution, that is updated to match so that the two records agree.

The picture data is copied byte for byte. The tests compare the picture bytes before and after, and check the written files against a separate Python script and the Pillow image library, which reads each as 300 DPI with identical pixels.

When to use it

Use it when a form, a print shop or a layout program asks for a minimum DPI and your file says 72, and the pixel count is already enough for the size you need. It cannot make a small picture sharp: for a given print size, check the pixels you need with the image DPI print size calculator. To look at or remove other metadata, use the image metadata viewer and remover. To change pixel size, use the image resizer, and to reduce file size, the image compressor.

Assumptions and limits

• Only PNG and JPEG files are supported. SVG, WebP, GIF and other formats are refused.
• The new DPI is between 1 and 60,000. JPEG stores whole numbers; PNG stores pixels per meter, rounded.
• The same value is written for horizontal and vertical resolution.
• The file is read and written in your browser. Nothing is uploaded.

Formulas reviewed October 10, 2026. See the calculation methodology for how SumPanda rounds, tests and sources its formulas.

Frequently asked questions