OpenAI Codex Mini vs 
GLM 5.3 Flash
GLM 5.3 Flash is cheaper than OpenAI Codex Mini at $0.15/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.
GLM 5.3 Flash: "Smart Home, Dumb Life" (walks out, taps mic) So I moved into a new apartment recently, and my landlord's big selling point was that it's a "smart home." Everything's connected. Lights, thermostat, doorbell, all of it. And I want to talk about what a lie that is. Because my smart home is not smart.
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.
GLM 5.3 Flash: Here are 5 jokes: Why don't scientists trust atoms? Because they make up everything! What do you call a fake noodle? An impasta! Why did the scarecrow win an award? Because he was outstanding in his field! I told my wife she was drawing her eyebrows too high. She looked surprised. Why don't skeletons fight each other?
Price and specs
Not enough votes to call it. On the specs, GLM 5.3 Flash has the edge: bigger model tier, newer, bigger context window. GLM 5.3 Flash costs 12x less per token.
| Spec | OpenAI Codex Mini | GLM 5.3 Flash |
|---|---|---|
| Input price | $1.5/M tokens | $0.15/M tokens |
| Output price | $6/M tokens | $0.5/M tokens |
| Context window | 200K tokens | 1.3M tokens |
| Weights | — | Open |
| Free API (OpenRouter) | No | No |
| Released | May 2025 | Aug 2026 |
| At 10M a month | $15.00 | $1.50 |
Input tokens at list price. No caching, no batch discount.
Where to run it
OpenAI Codex Mini
No hosts listed on OpenRouter.
GLM 5.3 Flash29 hosts
- OpenInferencefp4$0.03 in$0.72 out1M100% up
- Relace$0.04 in$0.50 out1M100% up
- Sail Researchfp4$0.04 in$0.60 out1M99.8% up
- Reka$0.06 in$1.60 out262k98.3% up
- InferenceNetfp4$0.07 in$0.50 out1M99.6% up
- Wafer$0.07 in$0.50 out1M100% up
23 more hostsFewer hosts
- DeepInfrafp4$0.07 in$0.25 out1M99% up
- StreamLakefp8$0.08 in$0.28 out1M98.5% up
- Novitafp8$0.08 in$0.28 out1M99.4% up
- GMI Cloudfp8$0.09 in$0.30 out1M99.6% up
- Decartfp4$0.09 in$0.31 out1M99.9% up
- Inceptronfp8$0.10 in$0.55 out1M95.8% up
- DekaLLM$0.10 in$1.00 out1M96.8% up
- Near AIfp8$0.10 in$0.35 out1M99.9% up
- Phalanvfp4$0.11 in$0.38 out1M100% up
- Morphfp8$0.13 in$0.70 out1M94.5% up
- Basetenfp8$0.15 in$0.50 out1M99.2% up
- CoreWeavenvfp4$0.15 in$0.50 out1M99.2% up
- Crusoefp4$0.15 in$0.50 out1M99% up
- DigitalOcean$0.15 in$0.50 out1M100% up
- Fireworks$0.15 in$0.50 out1M99.7% up
- Friendli$0.15 in$0.50 out1M100% up
- Modalnvfp4$0.15 in$0.50 out1M100% up
- Parasailfp4$0.15 in$0.50 out1M99.7% up
- SiliconFlowfp8$0.15 in$0.50 out1M94.1% up
- Together$0.15 in$0.50 out1M100% up
- Venice$0.15 in$0.50 out1M99.9% up
- Z.aifp8$0.15 in$0.50 out1M100% up
- AtlasCloudfp8Degraded on OpenRouter when checked, 10 Oct 2026$0.15 in$0.50 out1M92.8% up
Per million tokens. Prices and uptime via OpenRouter, checked 10 Oct 2026.
Common questions
What is the difference between OpenAI Codex Mini and GLM 5.3 Flash?
OpenAI Codex Mini is developed by OpenAI while GLM 5.3 Flash is developed by Zhipu AI. OpenAI Codex Mini has a 200K token context window vs GLM 5.3 Flash's 1.3M. You can compare their actual outputs across 8 challenges on Rival to see how they differ in practice.
Which is better, OpenAI Codex Mini or GLM 5.3 Flash?
It depends on your use case. OpenAI Codex Mini and GLM 5.3 Flash each have strengths in different areas. Rival lets you compare their real outputs side-by-side across 8 challenges so you can judge which fits your needs best.
How much does OpenAI Codex Mini cost compared to GLM 5.3 Flash?
OpenAI Codex Mini costs $1.5/M input tokens and GLM 5.3 Flash costs $0.15/M input tokens. GLM 5.3 Flash is $1.35/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 GLM 5.3 Flash on Rival?
This page shows a side-by-side comparison of OpenAI Codex Mini and GLM 5.3 Flash 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 Step 5 PreviewLanded Oct 2026
- GLM 5.3 Flash vs Claude Haiku 5.5Landed Oct 2026
- OpenAI Codex Mini vs Ling 3.1 FlashLanded Oct 2026
- GLM 5.3 Flash vs Mistral Large 4Landed Oct 2026
- OpenAI Codex Mini vs GPT-6.1 SolLanded Sep 2026
- GLM 5.3 Flash vs Claude Sonnet 5.5Landed Sep 2026
- OpenAI Codex Mini vs Solar Mini 4Landed Sep 2026
- GLM 5.3 Flash vs Qwen3.8 Max PrimeLanded 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
- GLM 5.3 Flash vs GLM 5.3Same lab
- GLM 5.3 Flash vs GLM 5.3 FlashXSame lab
- OpenAI Codex Mini vs Llama 3 70BNew provider
- GLM 5.3 Flash vs Llama 3.1 405BNew provider
- GLM 5.3 Flash vs Llama 3.1 70B (Instruct)Same size
- GLM 5.3 Flash vs Llama 4 MaverickNew provider
