Performance Benchmarks for gpt-5.1-codex

Analyze how gpt-5.1-codex stacks up against other frontier models in terms of cost-to-performance and raw intelligence (LMArena Elo).

2026 Performance Summary

🚀 Intelligence (Elo): 1336
💰 API Cost (Input): $0.00000125 / 1M tokens
⚡ API Cost (Output): $0.00001 / 1M tokens
⏱️ Real-world Throughput: 53 tokens/s

Analysis: While gpt-5.1-codex is a capable model, it is currently outperformed in efficiency by mimo-v2.5-pro. mimo-v2.5-pro sits higher on the Pareto line, offering approximately 131 points more intelligence (Elo) for a comparable or lower API cost.

Highly Recommended Alternatives

Frontier Model	LMArena Elo	API Cost (1M)	Throughput
mimo-v2.5-pro	1467	$4.35e-7	50
gemini-3.5-flash-lite	1459	$3e-7	70
hy3	1453	$1.32e-7	74
gemma-4-31b	1451	$1e-7	145.5
qwen3-235b-a22b-instruct-2507	1423	$9e-8	50

*These models represent the Pareto Frontier (optimal cost-to-performance).*