How to pronounce Elo

Elo is most commonly pronounced "ee loh" (/ˈiːloʊ/). This is one of several readings in active use; the developer community hasn't converged on a single answer.

The rating scale behind LMArena / Chatbot Arena leaderboards, cited as "Elo score" in most 2025-2026 model launch posts and eval blogs. It is the surname of Hungarian-American physics professor Arpad Elo (né Élő), not an acronym — Wikipedia states it is "written as 'Elo', not 'ELO'" — so spelling it out as letters E-L-O is the common mistake. Both EE-loh and EL-oh are accepted in English, with EE-loh listed first by Wikipedia and Wiktionary.

Alternate readings you might hear:

• "el oh" /ˈɛloʊ/

Source: Wikipedia — Elo rating system (footnote: written as "Elo", not "ELO"; /ˈiːloʊ/ or /ˈɛloʊ/)

Pronouncing project and product names correctly avoids the small but persistent friction of being gently corrected during standups, conference Q&As, and team calls. Hearing the word a few times locks in the right reading better than reading IPA ever will. Pronounce is a community-maintained dictionary — every entry tagged with a confidence level and (where possible) a citable source.