AI Model Release Tracker - Timeline of Major AI Models from 2022-2026

Gemini Omni vs GPT-5-Codex

Google
Gemini Omni
OpenAI
GPT-5-Codex
Overview
CompanyGoogleOpenAI
Release dateMay 19 2026Sep 15 2025
AccessProprietaryProprietary
Benchmarks
Nonsense detection
BullshitBench v2
39%
Timeline
Release gapGPT-5-Codex shipped 246 days before Gemini Omni

Which is better: Gemini Omni or GPT-5-Codex?

Gemini Omni and GPT-5-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. GPT-5-Codex shipped 246 days before Gemini Omni, so benchmark comparisons should account for the intervening progress.

Published specifications for these two models are limited — see each model page for the latest details.

Direct benchmark comparisons are unavailable — Gemini Omni and GPT-5-Codex don't publish scores on any of the same benchmarks.

Frequently asked questions

Gemini Omni was released by Google on May 19 2026.

GPT-5-Codex was released by OpenAI on Sep 15 2025.

Other comparisons