GPT-5.1 Codex Mini: benchmark results
OpenAI's compact Codex-specialized GPT-5.1 tier. Provider: OpenAI. Released 2025-11-19. Access: API.
Unified ELO 1600 ± 1, rank #266 of 1392 rated models, from 23 benchmark results.
Strongest benchmark results
| Benchmark | Score | Metric | Percentile |
|---|---|---|---|
| SnakeBench | 36.5 | TrueSkill Rating | 99.1 |
| LM Market Cap LMC Score | 87.8 | LMC Score (0-100) | 86.5 |
| AI Chess Leaderboard (Reasoning) | 952 | Elo | 76.2 |
| Terminal-Bench 2.0 | 61.6 | Accuracy (%) | 75 |
| BenchmarkList ECI | 129.34 | Capability Index (ECI) | 73.4 |
| AI Chess Leaderboard (Continuation) | 811 | Elo | 72.7 |
| BenchTable | 56.5 | Total Score (%) | 65.1 |
| Design Arena (Game Dev) | 1122 | Elo | 32.5 |
| Design Arena (Website) | 1126 | Elo | 30.1 |
| Design Arena (UI Components) | 1103 | Elo | 27.9 |
| Design Arena (Data Viz) | 1116 | Elo | 26.6 |
| Design Arena (ASCII Art) | 1128 | Elo | 20.7 |
Interactive version: theaggregate.ai/model?slug=gpt-5-1-codex-mini · How It Works · Data refreshed daily, snapshot 2026-09-05.