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

Gemini 1.5 Pro vs GPT-5-Codex

Google
Gemini 1.5 Pro
OpenAI
GPT-5-Codex
Overview
CompanyGoogleOpenAI
Release dateFeb 15 2024Sep 15 2025
AccessProprietaryProprietary
Benchmarks
Nonsense detection
BullshitBench v2
39%
Timeline
Release gapGemini 1.5 Pro shipped 578 days before GPT-5-Codex

Which is better: Gemini 1.5 Pro or GPT-5-Codex?

Gemini 1.5 Pro and GPT-5-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Gemini 1.5 Pro shipped 578 days before GPT-5-Codex, 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 1.5 Pro and GPT-5-Codex don't publish scores on any of the same benchmarks.

Frequently asked questions

Gemini 1.5 Pro was released by Google on Feb 15 2024.

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

Other comparisons