# Claude Opus 4.8 vs Grok 4.20

> Side-by-side benchmark comparison for Claude Opus 4.8 and Grok 4.20 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-opus-4-8-vs-grok-4-20-beta
- Last updated: October 10, 2026

- Shared sourced benchmarks: 14
- HTML indexing: indexable
- Ranking lane: BenchAlign v5.8

## Quick Verdict

Claude Opus 4.8 leads by point estimate. Conditional score ranges do not establish rank confidence. Choose using the category evidence and your own workload tests.

## Summary

- Claude Opus 4.8 has the higher overall point estimate 69.12 to 57.33. Conditional score ranges do not establish rank confidence.
- The clearest category separation is in coding, where the averages are 60.8 for Claude Opus 4.8 and 22.3 for Grok 4.20.
- The biggest single benchmark swing is Gert Labs in Agentic, with scores of 72.97% and 38.36%.
- 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 Opus 4.8 | Grok 4.20 |
|----------|----------|----------|
| Creator | Anthropic | xAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M | 2M |
| Overall Score | 69.12 | 57.33 |
| Benchmarks Covered | 40 | 23 |
| Pricing (input/output) | $5.00 / $25.00 | $1.25 / $2.50 |

## Category Breakdown

### Agentic

- Winner: Claude Opus 4.8
- Claude Opus 4.8 public-lane score: 61.6 (Supported · #20/123)
- Grok 4.20 public-lane score: 24.4 (Supported · #98/123)

| Benchmark | Claude Opus 4.8 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 21.1% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 74.6% | Coming soon | Coming soon |
| BrowseComp | 84.3% | Coming soon | Coming soon |
| DeepSearchQA | 93.1% | 62.8% | Claude Opus 4.8 |
| OSWorld-Verified | 83.4% | Coming soon | Coming soon |
| Finance Agent v2 | 53.9% | Coming soon | Coming soon |
| MCP Atlas | 82.2% | Coming soon | Coming soon |
| Toolathlon | 59.9% | Coming soon | Coming soon |
| Gert Labs | 72.97% | 38.36% | Claude Opus 4.8 |
| ResearchClawBench | 21.1% | Coming soon | Coming soon |
| OSWorld 2.0 | 20.6% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 71.9% | 44.2% | Claude Opus 4.8 |
| Terminal-Bench 2.0 | Coming soon | 47.1% | Coming soon |

### Coding

- Winner: Claude Opus 4.8
- Claude Opus 4.8 public-lane score: 60.8 (Supported · #19/146)
- Grok 4.20 public-lane score: 22.3 (Supported · #114/146)

| Benchmark | Claude Opus 4.8 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 88.6% | 76.7% | Claude Opus 4.8 |
| SWE-bench Pro | 69.2% | 51.8% | Claude Opus 4.8 |
| SWE Multilingual | 84.4% | Coming soon | Coming soon |
| SWE Multimodal | 38.4% | Coming soon | Coming soon |
| Terminal-Bench 2.1 | 74.6% | Coming soon | Coming soon |
| cursorBench31 | 58.4% | Coming soon | Coming soon |
| CursorBench 3.2 | 62.3% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | 46.5% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 87.8% | 84.3% | Claude Opus 4.8 |
| SWE-bench (Vals) | 88.6% | 72.2% | Claude Opus 4.8 |
| PostTrainBench v1.1 | 32.9% | Coming soon | Coming soon |
| LiveCodeBench Pro | Coming soon | 74.2% | Coming soon |
| Vibe Code Bench | Coming soon | 4.06% | Coming soon |

### Reasoning

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: 62.9 (#24/28)
- Grok 4.20 public-lane score: 44.9 (Unranked · 2 rankable rows)

| Benchmark | Claude Opus 4.8 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | 72.1% | 53.3% | Claude Opus 4.8 |
| ARC-AGI-3 | 1.5% | 0.1% | Claude Opus 4.8 |
| ARC-AGI-1 | 92.50% | Coming soon | Coming soon |

### Multimodal & Grounded

- Winner: Directional only
- Claude Opus 4.8 public-lane score: 91.2 (#5/54)
- Grok 4.20 public-lane score: 53.4 (#47/54)

| Benchmark | Claude Opus 4.8 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| OfficeQA Pro | 66.2% | Coming soon | Coming soon |
| ScreenSpot Pro | 87.9% | Coming soon | Coming soon |
| CharXiv | 89.9% | 60.9% | Claude Opus 4.8 |
| CharXiv w/o tools | 80.5% | Coming soon | Coming soon |
| MMMU-Pro | Coming soon | 75.2% | Coming soon |
| ERQA | Coming soon | 54.1% | Coming soon |
| SimpleVQA | Coming soon | 57.4% | Coming soon |
| MedXpertQA (MM) | Coming soon | 65.8% | Coming soon |

### Knowledge

- Winner: Claude Opus 4.8
- Claude Opus 4.8 public-lane score: 70.7 (Supported · #14/177)
- Grok 4.20 public-lane score: 53.1 (Supported · #66/177)

| Benchmark | Claude Opus 4.8 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| GPQA | 93.6% | Coming soon | Coming soon |
| GPQA-D | 93.6% | 88.5% | Claude Opus 4.8 |
| HLE | 57.9% | Coming soon | Coming soon |
| HLE w/o tools | 49.8% | 31.6% | Claude Opus 4.8 |
| GPQA Diamond (Vals) | 92.4% | 88.6% | Claude Opus 4.8 |
| MMLU-Pro (Vals) | 89.6% | 86.3% | Claude Opus 4.8 |
| HealthBench Hard | Coming soon | 20.3% | Coming soon |
| MedXpertQA (Text) | Coming soon | 50.2% | Coming soon |

### Multilingual

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: Coming soon
- Grok 4.20 public-lane score: Coming soon

| Benchmark | Claude Opus 4.8 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| INCLUDE | 87.6% | Coming soon | Coming soon |

### Instruction Following

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: 75.4 (#61/127)
- Grok 4.20 public-lane score: Coming soon

### Mathematics

- Winner: Not comparable
- Claude Opus 4.8 public-lane score: 65.7 (#2/7)
- Grok 4.20 public-lane score: Coming soon

| Benchmark | Claude Opus 4.8 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| USAMO 2026 | 96.7% | Coming soon | Coming soon |
| FrontierMath v2 (Tiers 1-3) | 47.241% | Coming soon | Coming soon |
| FrontierMath v2 (Tier 4) | 31.250% | Coming soon | Coming soon |

## FAQ

### Which is better overall, Claude Opus 4.8 or Grok 4.20?

Claude Opus 4.8 has the higher overall point estimate. Conditional score ranges do not establish rank confidence.

### Where is the biggest gap between Claude Opus 4.8 and Grok 4.20?

The widest category gap is in coding, where the averages are 60.8 for Claude Opus 4.8 and 22.3 for Grok 4.20.

### How many benchmarks does Claude Opus 4.8 cover on BenchLM?

Claude Opus 4.8 currently has 40 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 Opus 4.8 vs Grok 4.20 Multi-agent](/compare/claude-opus-4-8-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)
- [Claude Opus 4.8 vs Claude Opus 5.5](/compare/claude-opus-4-8-vs-claude-opus-5-5)
- [Grok 4.20 vs Claude Opus 5.5](/compare/claude-opus-5-5-vs-grok-4-20-beta)

## Explore More

- [Claude Opus 4.8 profile](/models/claude-opus-4-8)
- [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)