# Claude Sonnet 4.5 vs Grok 4.20

> Side-by-side benchmark comparison for Claude Sonnet 4.5 and Grok 4.20 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-sonnet-4-5-vs-grok-4-20-beta
- Last updated: September 10, 2026

- Shared sourced benchmarks: 4
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick Grok 4.20 if you want the stronger benchmark profile. Claude Sonnet 4.5 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Grok 4.20 leads overall 67.13 to 53.82.
- The clearest category separation is in coding, where the averages are 50.6 for Claude Sonnet 4.5 and 28.2 for Grok 4.20.
- The biggest single benchmark swing is ARC-AGI-2 in Reasoning, with scores of 13.6% and 53.3%.
- Grok 4.20 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.
- Grok 4.20 also has the larger context window at 2M.

## Model Snapshot

| Property | Claude Sonnet 4.5 | Grok 4.20 |
|----------|----------|----------|
| Creator | Anthropic | xAI |
| Type | Proprietary | Proprietary |
| Reasoning | Non-Reasoning | Reasoning |
| Context | 200K | 2M |
| Overall Score | 53.82 | 67.13 |
| Benchmarks Covered | 11 | 23 |
| Pricing (input/output) | $3.00 / $15.00 | $2.00 / $6.00 |

## Category Breakdown

### Agentic

- Winner: Coming soon
- Claude Sonnet 4.5 public-lane score: 44.2 (Estimated · #91/152)
- Grok 4.20 public-lane score: 26.7 (Supported · #145/152)

| Benchmark | Claude Sonnet 4.5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 2.0 | 50% | 47.1% | Claude Sonnet 4.5 |
| OSWorld-Verified | 61.4% | Coming soon | Coming soon |
| VITA-Bench | 17.0% | Coming soon | Coming soon |
| Gert Labs | 48.51% | 38.36% | Claude Sonnet 4.5 |
| JobBench | 27.7% | Coming soon | Coming soon |
| DeepSearchQA | Coming soon | 62.8% | Coming soon |
| Terminal-Bench 2.1 (Vals) | Coming soon | 44.2% | Coming soon |

### Coding

- Winner: Coming soon
- Claude Sonnet 4.5 public-lane score: 50.6 (Estimated · #54/151)
- Grok 4.20 public-lane score: 28.2 (Supported · #141/151)

| Benchmark | Claude Sonnet 4.5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 77.2% | 76.7% | Claude Sonnet 4.5 |
| LiveCodeBench Pro | Coming soon | 74.2% | Coming soon |
| SWE-bench Pro | Coming soon | 51.8% | Coming soon |
| Vibe Code Bench | Coming soon | 4.06% | Coming soon |
| LiveCodeBench (Vals) | Coming soon | 84.3% | Coming soon |
| SWE-bench (Vals) | Coming soon | 72.2% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Claude Sonnet 4.5 public-lane score: Coming soon
- Grok 4.20 public-lane score: 34.6 (#43/48)

| Benchmark | Claude Sonnet 4.5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| MMMU-Pro | Coming soon | 75.2% | Coming soon |
| CharXiv | Coming soon | 60.9% | Coming soon |
| ERQA | Coming soon | 54.1% | Coming soon |
| SimpleVQA | Coming soon | 57.4% | Coming soon |
| MedXpertQA (MM) | Coming soon | 65.8% | Coming soon |

### Reasoning

- Winner: Coming soon
- Claude Sonnet 4.5 public-lane score: 19.1 (Unranked · 1 rankable row)
- Grok 4.20 public-lane score: 34.2 (Unranked · 2 rankable rows)

| Benchmark | Claude Sonnet 4.5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 13.6% | 53.3% | Grok 4.20 |
| ARC-AGI-3 | Coming soon | 0.1% | Coming soon |

### Knowledge

- Winner: Coming soon
- Claude Sonnet 4.5 public-lane score: 51.2 (Estimated · #73/183)
- Grok 4.20 public-lane score: 49.4 (Supported · #85/183)

| Benchmark | Claude Sonnet 4.5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 83.4% | Coming soon | Coming soon |
| GPQA-D | Coming soon | 88.5% | Coming soon |
| HLE w/o tools | Coming soon | 31.6% | Coming soon |
| HealthBench Hard | Coming soon | 20.3% | Coming soon |
| MedXpertQA (Text) | Coming soon | 50.2% | Coming soon |
| GPQA Diamond (Vals) | Coming soon | 88.6% | Coming soon |
| MMLU-Pro (Vals) | Coming soon | 86.3% | Coming soon |

### Mathematics

- Winner: Coming soon
- Claude Sonnet 4.5 public-lane score: 34.8 (Unranked · 2 rankable rows)
- Grok 4.20 public-lane score: Coming soon

| Benchmark | Claude Sonnet 4.5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| AIME 2025 | 87% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 13.495% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 4.167% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Claude Sonnet 4.5 or Grok 4.20?

Grok 4.20 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Sonnet 4.5 and Grok 4.20?

The widest category gap is in coding, where the averages are 50.6 for Claude Sonnet 4.5 and 28.2 for Grok 4.20.

### How many benchmarks does Claude Sonnet 4.5 cover on BenchLM?

Claude Sonnet 4.5 currently has 11 sourced benchmark scores on BenchLM.

### How many benchmarks does Grok 4.20 cover on BenchLM?

Grok 4.20 currently has 23 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Sonnet 4.5 vs Claude Sonnet 4.5 Thinking](/compare/claude-sonnet-4-5-vs-claude-sonnet-4-5-thinking)
- [Grok 4.20 vs Claude Sonnet 4.5 Thinking](/compare/claude-sonnet-4-5-thinking-vs-grok-4-20-beta)
- [Claude Sonnet 4.5 vs Grok 4.20 Multi-agent](/compare/claude-sonnet-4-5-vs-grok-4-20-multi-agent-beta)
- [Grok 4.20 vs Grok 4.20 Multi-agent](/compare/grok-4-20-beta-vs-grok-4-20-multi-agent-beta)

## Explore More

- [Claude Sonnet 4.5 profile](/models/claude-sonnet-4-5)
- [Grok 4.20 profile](/models/grok-4-20-beta)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)