GPT-5.1 Codex Max vs Grok 4 Fast
Compare GPT-5.1 Codex Max and Grok 4 Fast side by side. See pricing, capabilities, context length, and performance. Use both on Krater.ai from $20/mo.
GPT-5.1 Codex Max vs Grok 4 Fast: strengths, best use cases and how to run both side by side. The live page adds context windows, token pricing and more comparisons once it loads.
Try both on Krater
Run GPT-5.1 Codex Max and Grok 4 Fast on the same prompt in the Krater Model Arena, then keep the winner in your workflow. One subscription covers both, from $20 a month.
Open Krater chat · GPT-5.1 Codex Max on Krater · Grok 4 Fast on Krater
How we compare models
Our tested head-to-heads run the same prompt set through both models in the Model Arena, then rank answers blind. Read the testing methodology, or browse every comparison.