OpenAI Codex Mini vs GPT-5.1
GPT-5.1 is cheaper than OpenAI Codex Mini at $1.25/M vs $1.5/M input tokens.
Pokémon Battle UI Recreation
Pokémon battle screen you can actually click. One HTML file.
Loading the build
Loading the build
Which answer wins?
Written rounds
2 promptsThree minutes of stand-up. Puns are banned.
OpenAI Codex Mini: [Comedian walks onstage] Hey, everyone! Great to see you all tonight. I'm Jamie—if you thought that intro was enthusiastic, you should've seen me when I realized this place has Wi-Fi. Seriously, though, I love stand-up.
GPT-5.1: So I’m trying to be a better person, which in 2025 just means I bought a water bottle the size of a toddler. That’s the whole self-improvement plan. It’s not therapy, it’s not reading books. It’s, “If I drink 3 of these, I’m emotionally stable.” I walk around with this thing like I’m on a hike… in my own apartment.
Five jokes on demand, then count how many were actually different.
OpenAI Codex Mini: Sure—here are five jokes: I asked the librarian if books about paranoia were available. She whispered, "They're right behind you." Why did the tomato turn red? Because it saw the salad dressing. I bought a boat because it was for sail. Don't trust stairs—they're always up to something.
GPT-5.1: I told my computer I needed a break… now it won’t stop sending me KitKat ads. Why don’t programmers like nature? It has too many bugs. I asked the librarian if the library had books on paranoia. She whispered, “They’re right behind you.” Why did the scarecrow become a successful motivational speaker?
Price and specs
Not enough votes to call it. On the specs, GPT-5.1 has the edge: bigger model tier, newer, bigger context window.
| Spec | OpenAI Codex Mini | GPT-5.1 |
|---|---|---|
| Input price | $1.5/M tokens | $1.25/M tokens |
| Output price | $6/M tokens | $10/M tokens |
| Context window | 200K tokens | 400K tokens |
| Weights | — | Closed |
| Free API (OpenRouter) | No | No |
| Released | May 2025 | Nov 2025 |
| SWE-bench Verified | 71.3% | 76.3% |
| At 10M a month | $15.00 | $12.50 |
Input tokens at list price. No caching, no batch discount.
Where to run it
OpenAI Codex Mini
No hosts listed on OpenRouter.
Per million tokens. Prices and uptime via OpenRouter, checked 6 Oct 2026.
Common questions
What is the difference between OpenAI Codex Mini and GPT-5.1?
Both are developed by OpenAI but target different use cases. OpenAI Codex Mini has a 200K token context window vs GPT-5.1's 400K. You can compare their actual outputs across 10 challenges on Rival to see how they differ in practice.
Which is better, OpenAI Codex Mini or GPT-5.1?
It depends on your use case. OpenAI Codex Mini and GPT-5.1 each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 10 challenges so you can judge which fits your needs best.
How much does OpenAI Codex Mini cost compared to GPT-5.1?
OpenAI Codex Mini costs $1.5/M input tokens and GPT-5.1 costs $1.25/M input tokens. GPT-5.1 is $0.25/M cheaper per input. Check their side-by-side outputs on Rival to see if the price difference is justified by quality.
How can I compare OpenAI Codex Mini and GPT-5.1 on Rival?
This page shows a side-by-side comparison of OpenAI Codex Mini and GPT-5.1 across shared challenges. You can vote on which model produced the better output in a blind duel. Browsing and voting are free. No account is needed to look; signing in only saves your votes and likes.
More comparisons
Against the newest arrivals
- OpenAI Codex Mini vs Ling 3.1 FlashLanded Oct 2026
- GPT-5.1 vs Mistral Large 4Landed Oct 2026
- OpenAI Codex Mini vs GPT-6.1 SolLanded Sep 2026
- GPT-5.1 vs Claude Sonnet 5.5Landed Sep 2026
- OpenAI Codex Mini vs Solar Mini 4Landed Sep 2026
- GPT-5.1 vs Qwen3.8 Max PrimeLanded Sep 2026
- OpenAI Codex Mini vs GLM 5.3 PrimeLanded Sep 2026
- GPT-5.1 vs Qwen3.8 Omni FlashLanded Sep 2026
Same lab, same size, long tail
- OpenAI Codex Mini vs GPT-6 Luna ProSame lab
- OpenAI Codex Mini vs GPT-6 Sol ProSame lab
- GPT-5.1 vs GPT-6.1 SolSame lab
- GPT-5.1 vs GPT-6 Luna ProSame lab
- OpenAI Codex Mini vs Gemma 4 26B A4BNew provider
- OpenAI Codex Mini vs Gemma 4 31BNew provider
- OpenAI Codex Mini vs GLM 5New provider
- OpenAI Codex Mini vs GLM 5 TurboSame size
