xAI's Opus-class flagship for frontier coding, agentic tool use, and knowledge work.
Previous-generation coding-optimized model for software engineering.
No shared demos for these models yet.
No captured outputs for these models yet.
Both Grok 4.5 and GPT 5.1 Codex are capable AI models. The best choice depends on your specific use case: consider pricing, context window, speed, and which capabilities (vision, reasoning, audio) you need.
Grok 4.5 has a lower blended cost. Grok 4.5: $2.00 input / $6.00 output. GPT 5.1 Codex: $1.25 input / $10.00 output.
Grok 4.5 has a larger context window: Grok 4.5 supports 500K tokens vs GPT 5.1 Codex at 400K tokens.
Yes, both Grok 4.5 and GPT 5.1 Codex support vision/image input.
Grok 4.5 and GPT 5.1 Codex have similar overall capabilities. The main differences lie in pricing, context window size, and provider-specific strengths. Use this comparison page to review all metrics side by side.
If cost is your priority, choose the cheaper option. If you need the highest intelligence for complex tasks, pick the higher-scoring model. For long documents or codebases, choose the larger context window. You can try both Grok 4.5 and GPT 5.1 Codex for free on idapt.app to see which performs better for your specific needs.