# F5 vs fo

> English confusable word pair

## The two words

### F5
*verb · frequency rank #34,052*
To refresh a webpage, especially if done continuously when waiting for an update.

### fo
*noun · frequency rank #12,049*
Abbreviation of folio, page and book size (10"-12.5" x 15"-20").

## Source
Compiled from Wiktionary via kaikki.org (CC BY-SA). Data vintage: 2026-05-06.
Canonical page: https://plainspell.com/en/vs/f5-vs-fo