Show text as big as the screen allows — for a cue card, a countdown, a title slide, or anything read from across a room.
Auto-fit is showing this at 120px — the largest size that fits without scrolling. Press Present to fill the whole screen — where the browser supports it, this uses the real Fullscreen API rather than just growing the box on the page, so the address bar and everything else are out of the way the way they would be for an actual cue card or slide.
Count words, characters, sentences and paragraphs, and see how long the text takes to read or say out loud.
Compare two versions of a text and see exactly what was added and removed — line by line, or word by word for prose.
Convert pixels to rem and back at any root font size, with a reference table for the sizes you actually use.
Every standard paper size in millimetres, inches and pixels — ISO A, B and C, US Letter and Legal, ANSI, architectural and JIS B.