OpenAI Codex Mini vs 
Grok 4.20 Beta
OpenAI Codex Mini is cheaper than Grok 4.20 Beta at $1.5/M vs $2/M input tokens.
Pokémon Battle UI Recreation
Pokémon battle screen you can actually click. One HTML file.
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Which answer wins?
Written rounds
2 promptsFive 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.
Grok 4.20 Beta: Here are 5 jokes: Why don't skeletons fight each other? They don't have the guts. Why did the scarecrow win an award? He was outstanding in his field. Why don't eggs tell jokes? They'd crack each other up. Why did the bicycle fall over? It was two tired. Why did the math book look sad? Because it had too many problems.
Three 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.
Grok 4.20 Beta: Stand-up Routine: "Adulting is a Scam" (Lights up. Comedian walks out with a coffee cup, takes a sip, immediately looks disappointed.) You ever notice how nobody warns you that being an adult is just childhood with bills and worse snacks?
Price and specs
Not enough votes to call it. On the specs, Grok 4.20 Beta has the edge: bigger model tier, newer, bigger context window.
| Spec | OpenAI Codex Mini | Grok 4.20 Beta |
|---|---|---|
| Input price | $1.5/M tokens | $2/M tokens |
| Output price | $6/M tokens | $6/M tokens |
| Context window | 200K tokens | 2.0M tokens |
| Weights | — | Closed |
| Free API (OpenRouter) | No | No |
| Released | May 2025 | Mar 2026 |
| At 10M a month | $15.00 | $20.00 |
Input tokens at list price. No caching, no batch discount.
Where to run it
OpenAI Codex Mini
No hosts listed on OpenRouter.
Grok 4.20 Beta1 host
Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.
Common questions
What is the difference between OpenAI Codex Mini and Grok 4.20 Beta?
OpenAI Codex Mini is developed by OpenAI while Grok 4.20 Beta is developed by xAI. OpenAI Codex Mini has a 200K token context window vs Grok 4.20 Beta's 2.0M. 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 Grok 4.20 Beta?
It depends on your use case. OpenAI Codex Mini and Grok 4.20 Beta 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 Grok 4.20 Beta?
OpenAI Codex Mini costs $1.5/M input tokens and Grok 4.20 Beta costs $2/M input tokens. OpenAI Codex Mini is $0.50/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 Grok 4.20 Beta on Rival?
This page shows a side-by-side comparison of OpenAI Codex Mini and Grok 4.20 Beta 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.
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