Gemini 1.5 Flash vs GPT-5.3-Codex
Google Gemini 1.5 Flash | OpenAI GPT-5.3-Codex | |
|---|---|---|
| Overview | ||
| Company | OpenAI | |
| Release date | May 14 2024 | Feb 5 2026 |
| Access | Proprietary | Proprietary |
| Benchmarks | ||
Nonsense detection BullshitBench v2Given a confidently-worded but nonsensical prompt, does the AI spot that it makes no sense and push back — instead of playing along and inventing an answer? The score is how often it clearly called out the nonsense. Higher is better. | — | 24% |
Next.js coding Next.js EvalsVercel's open eval of how well AI coding agents build and migrate real Next.js apps — measured as the share of tasks the agent completes successfully. Higher is better. | — | 83% |
Community preference (code) Arena Elo (Code)Like the text arena, but people vote on which AI writes better code. The votes become a chess-style Elo rating on arena.ai. Higher is better. | — | 1406 |
| Timeline | ||
| Release gap | Gemini 1.5 Flash shipped 632 days before GPT-5.3-Codex | |
Which is better: Gemini 1.5 Flash or GPT-5.3-Codex?
Gemini 1.5 Flash and GPT-5.3-Codex don't publish scores on any of the same benchmarks, so there's no direct head-to-head comparison. Gemini 1.5 Flash shipped 632 days before GPT-5.3-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 Flash and GPT-5.3-Codex don't publish scores on any of the same benchmarks.
Frequently asked questions
Gemini 1.5 Flash was released by Google on May 14 2024.
GPT-5.3-Codex was released by OpenAI on Feb 5 2026.
Other comparisons
Gemini 1.5 Flash vs Claude Sonnet 5GPT-5.3-Codex vs Claude Sonnet 5Gemini 1.5 Flash vs Muse Spark 1.1GPT-5.3-Codex vs Muse Spark 1.1Gemini 1.5 Flash vs Grok 4.5GPT-5.3-Codex vs Grok 4.5Gemini 1.5 Flash vs DeepSeek-V4-ProGPT-5.3-Codex vs DeepSeek-V4-ProGemini 1.5 Flash vs Mistral Medium 3.5GPT-5.3-Codex vs Mistral Medium 3.5Gemini 1.5 Flash vs Kimi K2.7 CodeGPT-5.3-Codex vs Kimi K2.7 Code