Model comparison
Claude Sonnet 5.5 vs Grok 3
Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 39.6 on the Noometry Index.
Last verified . 2 shared benchmarks.
Summary
- They share 2 benchmarks with published results for both. Claude Sonnet 5.5 scores higher in 5 categories and Grok 3 in 0 categories; 5 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Sonnet 5.5 leads 88.7 to 36.2.
- The biggest single-benchmark swing is OTIS Mock AIME 2024-2025: 100% for Claude Sonnet 5.5 and 55.6% for Grok 3.
Side by side
| Claude Sonnet 5.5 | Grok 3 | |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 60.5 | 39.6 |
| Released | 2026-09-28 | 2025-04-09 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | — |
| Max output | 128K | — |
| Input $ / M tokens | $2 | — |
| Output $ / M tokens | $10 | — |
| Results tracked | 16 | 40 |
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Category by category
Coding Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 65.5 (#6), Grok 3: 41.5 (#113)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| FrontierCode | 52.1% | — |
| Aider Polyglot | — | 53.3% |
| CursorBench | 55.5% | — |
| LMArena WebDev | 1699 | — |
| FrontierSWE | 61.9% | — |
| SciCode | 61% | — |
| WeirdML | — | 37.2% |
| LMArena Coding | — | 1432 |
| ALE-Bench | 1,819 | — |
Agentic & Tool Use Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 44.9 (#14), Grok 3: 30.2 (#69)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| APEX-Agents | 75.5% | — |
| BALROG | — | 29.5% |
Reasoning Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 52.4 (#29), Grok 3: 13.8 (#322)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| ARC-AGI-2 | — | 0% |
| SimpleBench | — | 36.1% |
| Kagi LLM Benchmark | — | 61.3% |
| ARC-AGI-1 | — | 5.5% |
| CritPt | 31.4% | — |
| LMArena Hard Prompts | — | 1433 |
| Mystery Game Puzzles | 65% | — |
| Epoch Capabilities Index | — | 138.34 |
Math Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 88.7 (#4), Grok 3: 36.2 (#122)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| OTIS Mock AIME 2024-2025 | 100% | 55.6% |
| FrontierMath (Tiers 1-3) | 88.8% | — |
| FrontierMath Tier 4 | 80.5% | — |
| ProofBench | 100% | — |
| Omni-MATH | — | 46.4% |
| LMArena Math | — | 1390 |
| MATH Level 5 | — | 88.7% |
| FrontierMath (Feb 2025 set) | — | 3.8% |
| FrontierMath Tier 4 (v1) | — | 0% |
Knowledge Claude Sonnet 5.5 leads
Claude Sonnet 5.5: 66.0 (#11), Grok 3: 46.0 (#76)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| GPQA Diamond | 95.6% | 75.8% |
| SimpleQA Verified | 46.5% | — |
| MMLU-Pro | — | 78.8% |
| Confabulations | — | 14.2% |
| Vectara Hallucination Rate | — | 5.8% |
| GPQA (HELM) | — | 65% |
| LMArena Expert | — | 1420 |
Multimodal Not comparable
Claude Sonnet 5.5: 53.2 (#5), Grok 3: —
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| Furniture Assembly | 75% | — |
Multilingual Not comparable
Claude Sonnet 5.5: —, Grok 3: 52.5 (#81)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| LMArena Non-English | — | 1411 |
| LMArena Chinese | — | 1448 |
| LMArena French | — | 1460 |
| LMArena German | — | 1431 |
| LMArena Japanese | — | 1389 |
| LMArena Korean | — | 1374 |
| LMArena Russian | — | 1416 |
| LMArena Spanish | — | 1417 |
Instruction Following Not comparable
Claude Sonnet 5.5: —, Grok 3: 75.2 (#69)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| IFEval | — | 88.4% |
| LMArena Instruction Following | — | 1409 |
Long Context Not comparable
Claude Sonnet 5.5: —, Grok 3: 38.7 (#187)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| Fiction.LiveBench | — | 58.3% |
| LMArena Longer Query | — | 1439 |
Writing & Preference Not comparable
Claude Sonnet 5.5: —, Grok 3: 56.0 (#136)
| Benchmark | Claude Sonnet 5.5 | Grok 3 |
|---|---|---|
| LMArena Text | — | 1426 |
| LMArena Creative Writing | — | 1414 |
| Short-Story Creative Writing | — | 76.4% |
| EQ-Bench Creative Writing | — | 1186 |
| WildBench | — | 84.9% |
| LMArena Multi-Turn | — | 1424 |
Frequently asked questions
Is Claude Sonnet 5.5 better than Grok 3?
Claude Sonnet 5.5 is the stronger model overall, scoring 60.5 to 39.6 on the Noometry Index.
Is Claude Sonnet 5.5 or Grok 3 better for coding?
Claude Sonnet 5.5 scores higher on coding benchmarks: 65.5 versus 41.5 in the Noometry coding category.
How many benchmarks do Claude Sonnet 5.5 and Grok 3 share?
2 benchmarks have published results for both models. Claude Sonnet 5.5 has 16 scored results on Noometry and Grok 3 has 40.