Model comparison
GPT-5.3 Chat vs Grok 3
GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 39.9 on the Noometry Index.
Last verified . 18 shared benchmarks.
Summary
- They share 18 benchmarks with published results for both. GPT-5.3 Chat scores higher in 4 categories and Grok 3 in 4 categories; 6 gaps are clear of the uncertainty.
- The widest gap is in reasoning, where GPT-5.3 Chat leads 28.5 to 13.7.
Side by side
| GPT-5.3 Chat | Grok 3 | |
|---|---|---|
| Provider | OpenAI | xAI |
| Noometry Index | 42.8 | 39.9 |
| Released | 2026-03-03 | 2025-04-09 |
| Weights | Proprietary | Proprietary |
| Context window | 128K | — |
| Max output | 16K | — |
| Input $ / M tokens | $1.75 | — |
| Output $ / M tokens | $14 | — |
| Results tracked | 18 | 40 |
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Category by category
Coding Too close to call
GPT-5.3 Chat: 41.4 (#124), Grok 3: 41.9 (#115)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| LMArena Coding | 1408 | 1432 |
| Aider Polyglot | — | 53.3% |
| WeirdML | — | 37.2% |
Agentic & Tool Use Not comparable
GPT-5.3 Chat: —, Grok 3: 30.5 (#76)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| BALROG | — | 29.5% |
Reasoning GPT-5.3 Chat leads
GPT-5.3 Chat: 28.5 (#102), Grok 3: 13.7 (#333)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| LMArena Hard Prompts | 1399 | 1434 |
| ARC-AGI-2 | — | 0% |
| SimpleBench | — | 36.1% |
| Kagi LLM Benchmark | — | 61.3% |
| ARC-AGI-1 | — | 5.5% |
| Epoch Capabilities Index | — | 138.33 |
Math Too close to call
GPT-5.3 Chat: 38.2 (#142), Grok 3: 38.0 (#145)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| LMArena Math | 1389 | 1391 |
| OTIS Mock AIME 2024-2025 | — | 55.6% |
| Omni-MATH | — | 46.4% |
| MATH Level 5 | — | 88.7% |
| FrontierMath (Feb 2025 set) | — | 3.8% |
| FrontierMath Tier 4 (v1) | — | 0% |
Knowledge Grok 3 leads
GPT-5.3 Chat: 38.8 (#140), Grok 3: 46.2 (#82)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| LMArena Expert | 1397 | 1421 |
| GPQA Diamond | — | 75.8% |
| MMLU-Pro | — | 78.8% |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 5.8% |
| GPQA (HELM) | — | 65% |
Multilingual Grok 3 leads
GPT-5.3 Chat: 50.3 (#124), Grok 3: 52.3 (#87)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| LMArena Non-English | 1382 | 1410 |
| LMArena Chinese | 1432 | 1448 |
| LMArena French | 1397 | 1460 |
| LMArena German | 1384 | 1431 |
| LMArena Japanese | 1352 | 1387 |
| LMArena Korean | 1346 | 1373 |
| LMArena Russian | 1400 | 1416 |
| LMArena Spanish | 1371 | 1417 |
Instruction Following Grok 3 leads
GPT-5.3 Chat: 72.8 (#129), Grok 3: 75.0 (#73)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| LMArena Instruction Following | 1378 | 1409 |
| IFEval | — | 88.4% |
Long Context GPT-5.3 Chat leads
GPT-5.3 Chat: 42.6 (#120), Grok 3: 38.7 (#192)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| LMArena Longer Query | 1396 | 1439 |
| Fiction.LiveBench | — | 58.3% |
Writing & Preference GPT-5.3 Chat leads
GPT-5.3 Chat: 63.1 (#68), Grok 3: 55.8 (#141)
| Benchmark | GPT-5.3 Chat | Grok 3 |
|---|---|---|
| LMArena Text | 1389 | 1426 |
| LMArena Creative Writing | 1355 | 1414 |
| EQ-Bench Creative Writing | 1690 | 1186 |
| LMArena Multi-Turn | 1412 | 1425 |
| Short-Story Creative Writing | — | 76.4% |
| WildBench | — | 84.9% |
Frequently asked questions
Is GPT-5.3 Chat better than Grok 3?
GPT-5.3 Chat is the stronger model overall, scoring 42.8 to 39.9 on the Noometry Index.
Is GPT-5.3 Chat or Grok 3 better for coding?
They score almost the same on coding (41.4 vs 41.9); test both on your own repository before choosing.
How many benchmarks do GPT-5.3 Chat and Grok 3 share?
18 benchmarks have published results for both models. GPT-5.3 Chat has 18 scored results on Noometry and Grok 3 has 40.