Model comparison
GPT-5-Codex vs Grok-3 mini
Grok-3 mini is the stronger model overall, scoring 41.2 to 37.9 on the Noometry Index.
Last verified . 2 shared benchmarks.
Summary
- They share 2 benchmarks with published results for both. GPT-5-Codex scores higher in 2 categories and Grok-3 mini in 0 categories; 2 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5-Codex leads 30.9 to 13.6.
- The biggest single-benchmark swing is WeirdML: 54.5% for GPT-5-Codex and 42.6% for Grok-3 mini.
Side by side
| GPT-5-Codex | Grok-3 mini | |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 37.9 | 41.2 |
| Released | 2025-09-15 | 2025-04-09 |
| Weights | Proprietary | Proprietary |
| Context window | 400K | — |
| Max output | 128K | — |
| Input $ / M tokens | $1.25 | — |
| Output $ / M tokens | $10 | — |
| Results tracked | 3 | 35 |
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Category by category
Coding GPT-5-Codex leads
GPT-5-Codex: 42.4 (#103), Grok-3 mini: 40.8 (#131)
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| WeirdML | 54.5% | 42.6% |
| Aider Polyglot | — | 49.3% |
| LMArena Coding | — | 1379 |
Agentic & Tool Use Not comparable
GPT-5-Codex: 31.0 (#72), Grok-3 mini: —
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| Terminal-Bench | 44.3% | — |
Reasoning GPT-5-Codex leads
GPT-5-Codex: 30.9 (#83), Grok-3 mini: 13.6 (#334)
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| Kagi LLM Benchmark | 70.3% | 61.3% |
| ARC-AGI-2 | — | 0.4% |
| ARC-AGI-1 | — | 16.5% |
| LMArena Hard Prompts | — | 1375 |
| Epoch Capabilities Index | — | 140.35 |
Math Not comparable
GPT-5-Codex: —, Grok-3 mini: 42.1 (#85)
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| OTIS Mock AIME 2024-2025 | — | 77.8% |
| Omni-MATH | — | 31.8% |
| LMArena Math | — | 1386 |
| MATH Level 5 | — | 90.9% |
| FrontierMath (Feb 2025 set) | — | 5.9% |
Knowledge Not comparable
GPT-5-Codex: —, Grok-3 mini: 46.4 (#81)
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| GPQA Diamond | — | 76.3% |
| MMLU-Pro | — | 79.9% |
| Confabulations | — | 10.8% |
| GPQA (HELM) | — | 67.5% |
| LMArena Expert | — | 1395 |
Multilingual Not comparable
GPT-5-Codex: —, Grok-3 mini: 48.1 (#145)
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| LMArena Non-English | — | 1352 |
| LMArena Chinese | — | 1387 |
| LMArena French | — | 1357 |
| LMArena German | — | 1349 |
| LMArena Japanese | — | 1342 |
| LMArena Korean | — | 1335 |
| LMArena Russian | — | 1353 |
| LMArena Spanish | — | 1381 |
Instruction Following Not comparable
GPT-5-Codex: —, Grok-3 mini: 78.5 (#9)
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| IFEval | — | 95.1% |
| LMArena Instruction Following | — | 1357 |
Long Context Not comparable
GPT-5-Codex: —, Grok-3 mini: 41.0 (#147)
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| Fiction.LiveBench | — | 66.7% |
| LMArena Longer Query | — | 1372 |
Writing & Preference Not comparable
GPT-5-Codex: —, Grok-3 mini: 52.5 (#169)
| Benchmark | GPT-5-Codex | Grok-3 mini |
|---|---|---|
| LMArena Text | — | 1370 |
| LMArena Creative Writing | — | 1342 |
| Short-Story Creative Writing | — | 73.5% |
| WildBench | — | 65.1% |
| LMArena Multi-Turn | — | 1355 |
Frequently asked questions
Is GPT-5-Codex better than Grok-3 mini?
Grok-3 mini is the stronger model overall, scoring 41.2 to 37.9 on the Noometry Index.
Is GPT-5-Codex or Grok-3 mini better for coding?
GPT-5-Codex scores higher on coding benchmarks: 42.4 versus 40.8 in the Noometry coding category.
How many benchmarks do GPT-5-Codex and Grok-3 mini share?
2 benchmarks have published results for both models. GPT-5-Codex has 3 scored results on Noometry and Grok-3 mini has 35.