Model comparison
GPT-5.3 Codex vs Grok-3 mini
GPT-5.3 Codex is the stronger model overall, scoring 45.5 to 41.0 on the Noometry Index.
Last verified . 2 shared benchmarks.
Summary
- They share 2 benchmarks with published results for both. GPT-5.3 Codex scores higher in 1 category and Grok-3 mini in 0 categories; one gap is clear of the uncertainty.
- The widest gap is in coding, where GPT-5.3 Codex leads 48.5 to 40.4.
- The biggest single-benchmark swing is WeirdML: 79.3% for GPT-5.3 Codex and 42.6% for Grok-3 mini.
Side by side
| GPT-5.3 Codex | Grok-3 mini | |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 45.5 | 41.0 |
| Released | 2026-02-05 | 2025-04-09 |
| Weights | Proprietary | Proprietary |
| Context window | 400K | — |
| Max output | 128K | — |
| Input $ / M tokens | $1.75 | — |
| Output $ / M tokens | $14 | — |
| Results tracked | 8 | 35 |
Sponsored placements are available on pages like this one. Advertise on Noometry
Category by category
Coding GPT-5.3 Codex leads
GPT-5.3 Codex: 48.5 (#51), Grok-3 mini: 40.4 (#126)
| Benchmark | GPT-5.3 Codex | Grok-3 mini |
|---|---|---|
| WeirdML | 79.3% | 42.6% |
| SWE-bench Verified | 74.8% | — |
| Aider Polyglot | — | 49.3% |
| LMArena WebDev | 1408 | — |
| LMArena Coding | — | 1380 |
| ALE-Bench | 1,655 | — |
Agentic & Tool Use Not comparable
GPT-5.3 Codex: 47.8 (#9), Grok-3 mini: —
| Benchmark | GPT-5.3 Codex | Grok-3 mini |
|---|---|---|
| Terminal-Bench | 78.4% | — |
| METR Time Horizons | 74.5% | — |
| Vending-Bench 2 | 5,940 | — |
Reasoning Not comparable
GPT-5.3 Codex: —, Grok-3 mini: 13.8 (#323)
| Benchmark | GPT-5.3 Codex | Grok-3 mini |
|---|---|---|
| Epoch Capabilities Index | 156.84 | 140.35 |
| ARC-AGI-2 | — | 0.4% |
| Kagi LLM Benchmark | — | 61.3% |
| ARC-AGI-1 | — | 16.5% |
| LMArena Hard Prompts | — | 1374 |
Math Not comparable
GPT-5.3 Codex: —, Grok-3 mini: 40.3 (#78)
| Benchmark | GPT-5.3 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-5.3 Codex: —, Grok-3 mini: 46.3 (#75)
| Benchmark | GPT-5.3 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-5.3 Codex: —, Grok-3 mini: 48.3 (#141)
| Benchmark | GPT-5.3 Codex | Grok-3 mini |
|---|---|---|
| LMArena Non-English | — | 1352 |
| LMArena Chinese | — | 1387 |
| LMArena French | — | 1357 |
| LMArena German | — | 1350 |
| LMArena Japanese | — | 1343 |
| LMArena Korean | — | 1336 |
| LMArena Russian | — | 1352 |
| LMArena Spanish | — | 1379 |
Instruction Following Not comparable
GPT-5.3 Codex: —, Grok-3 mini: 78.7 (#8)
| Benchmark | GPT-5.3 Codex | Grok-3 mini |
|---|---|---|
| IFEval | — | 95.1% |
| LMArena Instruction Following | — | 1356 |
Long Context Not comparable
GPT-5.3 Codex: —, Grok-3 mini: 41.0 (#142)
| Benchmark | GPT-5.3 Codex | Grok-3 mini |
|---|---|---|
| Fiction.LiveBench | — | 66.7% |
| LMArena Longer Query | — | 1372 |
Writing & Preference Not comparable
GPT-5.3 Codex: —, Grok-3 mini: 52.7 (#163)
| Benchmark | GPT-5.3 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-5.3 Codex better than Grok-3 mini?
GPT-5.3 Codex is the stronger model overall, scoring 45.5 to 41.0 on the Noometry Index.
Is GPT-5.3 Codex or Grok-3 mini better for coding?
GPT-5.3 Codex scores higher on coding benchmarks: 48.5 versus 40.4 in the Noometry coding category.
How many benchmarks do GPT-5.3 Codex and Grok-3 mini share?
2 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Grok-3 mini has 35.