Resolution: Fax Quality Explained

What Is Fax Resolution?

Fax resolution measures how many dots per inch (dpi) a document is scanned and transmitted at, which directly determines how sharp or legible the page looks once it's received. A higher resolution captures more detail, but takes longer to transmit and can use more pages of data to send.

Standard, Fine, and Super Fine Resolution

• Standard resolution (roughly 200 x 100 dpi): the fastest setting, suited to most typed text where fine detail doesn't matter much.
• Fine resolution (roughly 200 x 200 dpi): roughly doubles the vertical detail, making small print easier to read.
• Super Fine resolution (roughly 200 x 400 dpi or higher): adds further vertical detail again, generally reserved for documents with fine print or line art where legibility at Fine still falls short.

Photo Resolution

Photo resolution is a separate mode some devices offer specifically for images and continuous-tone graphics rather than text, since a resolution setting tuned for sharp text edges doesn't always render a photo well. It trades off against transmission time the same way the other tiers do: more detail in exchange for a slower send.

How Fax.Plus Handles Resolution

Fax.Plus offers a Standard mode tuned for fast, clear text and a High Definition (HD) mode built for documents with images or fine detail, supporting resolutions up to 400 x 400 dpi. The resolution actually received still depends on the recipient's fax device: if it only supports a lower dpi, the fax arrives at that lower resolution regardless of what was selected when sending. Resolution works alongside the contrast setting to determine how legible a scanned page ends up, and the underlying page encoding both settings affect is defined by the ITU-T standard that defines page encoding, the same standard that governs a physical fax machine's hardware limits on resolution.