Model comparison
Claude Opus 5 vs Grok 4.5
Claude Opus 5 is the stronger model overall, scoring 67.8 to 55.0 on the Noometry Index. Grok 4.5 costs 3.3× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.
Last verified . 49 shared benchmarks.
Summary
- They share 49 benchmarks with published results for both. Claude Opus 5 scores higher in 10 categories and Grok 4.5 in 0 categories; 10 gaps are clear of the uncertainty.
- The widest gap is in math, where Claude Opus 5 leads 86.2 to 60.9.
- The biggest single-benchmark swing is ProofBench: 99% for Claude Opus 5 and 31% for Grok 4.5.
- Grok 4.5 is cheaper at $2 / $6 per million input/output tokens, against $5 / $25 for Claude Opus 5.
- Claude Opus 5 accepts more context: 1M tokens versus 500K.
Side by side
| Claude Opus 5 | Grok 4.5 | |
|---|---|---|
| Provider | Anthropic | xAI |
| Noometry Index | 67.8 | 55.0 |
| Released | 2026-07-24 | 2026-07-08 |
| Weights | Proprietary | Proprietary |
| Context window | 1M | 500K |
| Max output | 128K | 500K |
| Input $ / M tokens | $5 | $2 |
| Output $ / M tokens | $25 | $6 |
| Results tracked | 57 | 52 |
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Category by category
Coding Claude Opus 5 leads
Claude Opus 5: 67.5 (#5), Grok 4.5: 52.2 (#35)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| DeepSWE | 73.6% | 53.8% |
| FrontierCode | 53.4% | 42.4% |
| LMArena WebDev | 1691 | 1553 |
| SciCode | 56.4% | 54.1% |
| WeirdML | 91.8% | 46.4% |
| LMArena Coding | 1534 | 1474 |
| ALE-Bench | 2,165 | 1,309 |
| CursorBench | 46.6% | — |
| FrontierSWE | 52% | — |
Agentic & Tool Use Claude Opus 5 leads
Claude Opus 5: 55.6 (#1), Grok 4.5: 44.4 (#17)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| APEX-Agents | 65.8% | 56.2% |
| τ²-bench Banking | 48.7% | 47.9% |
| PostTrainBench | 35% | 23.4% |
| GBAEval | 79.6% | 65.4% |
| GDP.pdf | 24% | 14% |
| Vending-Bench 2 | 11,182 | 3,887 |
| OSWorld 2.0 | 31.4% | — |
| BALROG | 63.4% | — |
| LMArena Search | — | 1213 |
Reasoning Claude Opus 5 leads
Claude Opus 5: 77.2 (#4), Grok 4.5: 56.1 (#25)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| ARC-AGI-2 | 90.4% | 52.6% |
| SimpleBench | 80.6% | 70% |
| NYT Connections (extended) | 94.3% | 79.9% |
| ARC-AGI-1 | 97.5% | 87.2% |
| CritPt | 29.1% | 15.4% |
| Chess Puzzles | 42% | 36% |
| LMArena Hard Prompts | 1526 | 1462 |
| DTBench | 97.9% | 96.5% |
| LMCA | 64.5% | 45.2% |
| Epoch Capabilities Index | 162.78 | 153.92 |
| Kagi LLM Benchmark | — | 83.5% |
| EBR-Bench | 45.7% | — |
| Mystery Game Puzzles | 59% | — |
| Surface Evolver Bench | — | 74.4% |
| Bench to the Future 3 | 0.12 | — |
Math Claude Opus 5 leads
Claude Opus 5: 86.2 (#8), Grok 4.5: 60.9 (#35)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| FrontierMath (Tiers 1-3) | 85.6% | 57.2% |
| FrontierMath Tier 4 | 73.2% | 24.4% |
| OTIS Mock AIME 2024-2025 | 98.9% | 97.8% |
| ProofBench | 99% | 31% |
| LMArena Math | 1531 | 1459 |
Knowledge Claude Opus 5 leads
Claude Opus 5: 66.8 (#9), Grok 4.5: 62.3 (#24)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| GPQA Diamond | 93.9% | 93.4% |
| SimpleQA Verified | 59.9% | 48.3% |
| LMArena Expert | 1557 | 1466 |
Multimodal Claude Opus 5 leads
Claude Opus 5: 50.8 (#8), Grok 4.5: 37.6 (#72)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| LMArena Vision | 1319 | 1288 |
| Blueprint-Bench 2 | 30.4% | 27.3% |
| Furniture Assembly | 60.8% | 22.5% |
| LMArena Document | 1516 | 1452 |
Multilingual Claude Opus 5 leads
Claude Opus 5: 58.8 (#4), Grok 4.5: 54.4 (#42)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| LMArena Non-English | 1501 | 1440 |
| LMArena Chinese | 1574 | 1496 |
| LMArena French | 1519 | 1456 |
| LMArena German | 1524 | 1446 |
| LMArena Japanese | 1516 | 1428 |
| LMArena Korean | 1521 | 1404 |
| LMArena Russian | 1507 | 1448 |
| LMArena Spanish | 1519 | 1450 |
Instruction Following Claude Opus 5 leads
Claude Opus 5: 79.2 (#7), Grok 4.5: 76.0 (#48)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| LMArena Instruction Following | 1517 | 1446 |
Long Context Claude Opus 5 leads
Claude Opus 5: 46.5 (#21), Grok 4.5: 44.8 (#56)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| LMArena Longer Query | 1515 | 1463 |
Writing & Preference Claude Opus 5 leads
Claude Opus 5: 79.2 (#1), Grok 4.5: 65.8 (#42)
| Benchmark | Claude Opus 5 | Grok 4.5 |
|---|---|---|
| LMArena Text | 1507 | 1448 |
| LMArena Creative Writing | 1491 | 1442 |
| EQ-Bench Creative Writing | 2133 | 1579 |
| LMArena Multi-Turn | 1499 | 1456 |
| EQ-Bench 4 | 1385 | — |
Frequently asked questions
Is Claude Opus 5 better than Grok 4.5?
Claude Opus 5 is the stronger model overall, scoring 67.8 to 55.0 on the Noometry Index. Grok 4.5 costs 3.3× less per token, which makes it the better buy when Claude Opus 5's lead doesn't matter for your workload.
Which is cheaper, Claude Opus 5 or Grok 4.5?
Grok 4.5 is cheaper. It lists at $2 per million input tokens and $6 per million output tokens; Claude Opus 5 lists at $5 and $25.
Is Claude Opus 5 or Grok 4.5 better for coding?
Claude Opus 5 scores higher on coding benchmarks: 67.5 versus 52.2 in the Noometry coding category.
Which has the bigger context window?
Claude Opus 5 does, with 1M tokens against 500K.
How many benchmarks do Claude Opus 5 and Grok 4.5 share?
49 benchmarks have published results for both models. Claude Opus 5 has 57 scored results on Noometry and Grok 4.5 has 52.