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Image DPI Changer

Change the DPI of a JPG or PNG to 72, 150, 300, 600, or any value. Pixel data is preserved exactly. Runs in your browser, nothing is uploaded.

Image DPI changer

Target DPI

DPI versus pixels: what this tool does, and what it does not do

  • DPI (dots per inch) is a metadata flag that tells layout software and printers how many pixels equal one inch on paper. Changing it does not add or remove image data.
  • A 3000 x 2400 pixel photo prints at 10 x 8 inches at 300 DPI, or 20 x 16 inches at 150 DPI. The pixel grid is identical in both cases.
  • If you need more pixels (so the same physical size prints at a higher quality grade), use the Image Resizer. This tool will not upscale your photo.
  • If you need fewer pixels (so the file is smaller on disk), use the Image Compressor or Image Resizer. DPI alone does not change file size meaningfully.
  • For JPEGs without a JFIF header, a fresh APP0 segment is inserted right after the SOI marker. EXIF, ICC, and other segments are kept in place.
  • For PNGs the pHYs chunk is written or rewritten in pixels per meter, using the IEEE 802.3 CRC32 polynomial expected by every PNG decoder.

How to use

  1. Drop a JPG or PNG image or click the upload area to choose a file.
  2. Pick a DPI preset (72, 96, 150, 200, 300, or 600) or type a custom value.
  3. Optionally unlink horizontal and vertical DPI for asymmetric print jobs.
  4. Click Download to save the file with the new DPI. Pixel data is preserved exactly.

About this tool

Image DPI Changer rewrites the DPI (also called PPI, pixels per inch) metadata inside a JPG or PNG file without re-encoding pixel data. The image grid stays byte-for-byte identical; only the physical-size hint that printers, InDesign, Illustrator, Word, Etsy, Printful, Society6, Redbubble, and university paper templates read is updated. Pick from 72, 96, 150, 200, 300, or 600 DPI presets, or type any custom value between 1 and 9600 DPI on either axis. The tool shows the original DPI it read from the file (or the assumed 72 DPI when no metadata is present), the new value, the print size in inches and centimeters before and after, and whether the image fits standard sheets like US Letter, A4, A3, 4 x 6, 5 x 7, and 8 x 10 at the new DPI with the maximum DPI you could reach by filling each sheet. For PNGs the pHYs chunk is written or rewritten in pixels per meter, with the IEEE 802.3 CRC32 every PNG decoder expects. For JPEGs the APP0 JFIF segment is patched in place, or a fresh 18-byte JFIF segment is inserted right after the SOI marker when the file does not have one (which is common in EXIF-only JPEGs from modern phones). EXIF, ICC, color profiles, and every other segment are preserved. Files are read with the browser File API and never uploaded.

Free to use. Works in your browser. No signup, no login.

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