Model comparison
GPT-5.3 Codex vs Grok 4.6
Grok 4.6 is the stronger model overall, scoring 56.9 to 45.8 on the Noometry Index.
Last verified . 5 shared benchmarks.
Summary
- They share 5 benchmarks with published results for both. GPT-5.3 Codex scores higher in 1 category and Grok 4.6 in 1 category; 2 gaps are clear of the uncertainty.
- The widest gap is in coding, where Grok 4.6 leads 58.5 to 48.6.
- The biggest single-benchmark swing is WeirdML: 79.3% for GPT-5.3 Codex and 67.3% for Grok 4.6.
- Grok 4.6 is cheaper at $2 / $6 per million input/output tokens, against $1.75 / $14 for GPT-5.3 Codex.
- Grok 4.6 accepts more context: 500K tokens versus 400K.
Side by side
| GPT-5.3 Codex | Grok 4.6 | |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 45.8 | 56.9 |
| Released | 2026-02-05 | 2026-08-12 |
| Weights | Proprietary | Proprietary |
| Context window | 400K | 500K |
| Max output | 128K | 500K |
| Input $ / M tokens | $1.75 | $2 |
| Output $ / M tokens | $14 | $6 |
| Results tracked | 8 | 49 |
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Category by category
Coding Grok 4.6 leads
GPT-5.3 Codex: 48.6 (#56), Grok 4.6: 58.5 (#16)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| LMArena WebDev | 1409 | 1617 |
| WeirdML | 79.3% | 67.3% |
| ALE-Bench | 1,655 | 1,508 |
| SWE-bench Verified | 74.8% | — |
| DeepSWE | — | 67.5% |
| FrontierCode | — | 48% |
| CursorBench | — | 41.4% |
| FrontierSWE | — | 25.3% |
| SciCode | — | 56.5% |
| LMArena Coding | — | 1465 |
Agentic & Tool Use GPT-5.3 Codex leads
GPT-5.3 Codex: 48.0 (#9), Grok 4.6: 39.4 (#27)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| Vending-Bench 2 | 5,940 | 9,047 |
| Terminal-Bench | 78.4% | — |
| APEX-Agents | — | 65.3% |
| GDP.pdf | — | 17.2% |
| METR Time Horizons | 74.5% | — |
Reasoning Not comparable
GPT-5.3 Codex: —, Grok 4.6: 61.4 (#20)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| Epoch Capabilities Index | 156.77 | 156.44 |
| ARC-AGI-2 | — | 67.1% |
| SimpleBench | — | 75.9% |
| NYT Connections (extended) | — | 80% |
| ARC-AGI-1 | — | 87.5% |
| CritPt | — | 19.7% |
| Chess Puzzles | — | 40% |
| EBR-Bench | — | 30.5% |
| LMArena Hard Prompts | — | 1447 |
| Mystery Game Puzzles | — | 34% |
| DTBench | — | 97.3% |
| LMCA | — | 48.5% |
Math Not comparable
GPT-5.3 Codex: —, Grok 4.6: 67.0 (#24)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| FrontierMath (Tiers 1-3) | — | 66% |
| FrontierMath Tier 4 | — | 31.7% |
| OTIS Mock AIME 2024-2025 | — | 99.2% |
| ProofBench | — | 51% |
| LMArena Math | — | 1423 |
Knowledge Not comparable
GPT-5.3 Codex: —, Grok 4.6: 63.3 (#20)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| GPQA Diamond | — | 94% |
| SimpleQA Verified | — | 49.3% |
| LMArena Expert | — | 1467 |
Multimodal Not comparable
GPT-5.3 Codex: —, Grok 4.6: 43.6 (#23)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| LMArena Vision | — | 1263 |
| Blueprint-Bench 2 | — | 33.2% |
| Furniture Assembly | — | 40% |
| LMArena Document | — | 1452 |
Multilingual Not comparable
GPT-5.3 Codex: —, Grok 4.6: 53.0 (#74)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| LMArena Non-English | — | 1420 |
| LMArena Chinese | — | 1480 |
| LMArena French | — | 1461 |
| LMArena German | — | 1431 |
| LMArena Japanese | — | 1376 |
| LMArena Korean | — | 1397 |
| LMArena Russian | — | 1422 |
| LMArena Spanish | — | 1404 |
Instruction Following Not comparable
GPT-5.3 Codex: —, Grok 4.6: 75.4 (#63)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| LMArena Instruction Following | — | 1431 |
Long Context Not comparable
GPT-5.3 Codex: —, Grok 4.6: 44.5 (#66)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| LMArena Longer Query | — | 1454 |
Writing & Preference Not comparable
GPT-5.3 Codex: —, Grok 4.6: 62.3 (#80)
| Benchmark | GPT-5.3 Codex | Grok 4.6 |
|---|---|---|
| LMArena Text | — | 1428 |
| LMArena Creative Writing | — | 1428 |
| LMArena Multi-Turn | — | 1425 |
Frequently asked questions
Is GPT-5.3 Codex better than Grok 4.6?
Grok 4.6 is the stronger model overall, scoring 56.9 to 45.8 on the Noometry Index.
Which is cheaper, GPT-5.3 Codex or Grok 4.6?
Grok 4.6 is cheaper. It lists at $2 per million input tokens and $6 per million output tokens; GPT-5.3 Codex lists at $1.75 and $14.
Is GPT-5.3 Codex or Grok 4.6 better for coding?
Grok 4.6 scores higher on coding benchmarks: 58.5 versus 48.6 in the Noometry coding category.
Which has the bigger context window?
Grok 4.6 does, with 500K tokens against 400K.
How many benchmarks do GPT-5.3 Codex and Grok 4.6 share?
5 benchmarks have published results for both models. GPT-5.3 Codex has 8 scored results on Noometry and Grok 4.6 has 49.