About SetDPI

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Casey Marlin

Builder of small, honest web tools. SetDPI exists because changing an image's DPI tag for a print shop or a form submission should not require installing Photoshop, paying a subscription, or uploading private photos to someone else's server.

What SetDPI does

SetDPI rewrites the DPI/PPI metadata inside JPEG and PNG files — the tag that tells printers and layout software how many pixels map to a printed inch. It changes the label, not the pixels: your image's quality, dimensions, and file size stay the same.

The entire process runs in your browser using the File API. Your images are never uploaded to a server. Go offline after loading the page and it still works — that is the proof.

Principles

Local-first, verifiably. There is no upload endpoint. The page is static HTML, JavaScript, and CSS served from GitHub Pages. No backend, no database, no image processing server.
Honest claims only. The tool changes metadata, not resolution. Pages like "Convert Image to 300 DPI" explain plainly that increasing the DPI tag does not add pixels or improve print quality — it changes how printers interpret existing pixels.
Format support is stated, not stretched. SetDPI handles JPEG (JFIF and EXIF) and PNG (pHYs chunk). It does not claim to handle TIFF, WebP, HEIC, or RAW. Unsupported formats are rejected with a clear message and, where possible, a redirect to a dedicated tool.

The guides

The topic pages (DPI for printing, DPI vs PPI, standard DPI settings, and others) are reference material written to answer the questions people actually search for. They are checked against current software versions and carry a last-checked date. Where a page states a fact, it cites the source — an ICC spec, an OS release note, a printer manufacturer's documentation.

Contact

Questions, corrections, or partnership inquiries: support@setdpi.com.

Disclaimer

SetDPI is an independent project. It is not affiliated with, endorsed by, or sponsored by Adobe, Apple, Microsoft, Google, Canon, Epson, or any printer manufacturer. Product names mentioned in the guides are trademarks of their respective owners, used only to describe compatibility. All writing on this site is original.