# Claude Fable 5 vs Grok 4.20

> Side-by-side benchmark comparison for Claude Fable 5 and Grok 4.20 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

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

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

## Quick Verdict

Pick Claude Fable 5 if you want the stronger benchmark profile. Grok 4.20 only makes more sense when its price, context window, or workload-specific category wins matter more than the overall score.

## Summary

- Claude Fable 5 leads overall 80.9 to 67.01.
- The clearest category separation is in coding, where the averages are 76.9 for Claude Fable 5 and 28.2 for Grok 4.20.
- The biggest single benchmark swing is Terminal-Bench 2.0 in Agentic, with scores of 84.3% and 47.1%.
- 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 Fable 5 | Grok 4.20 |
|----------|----------|----------|
| Creator | Anthropic | xAI |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M+ | 2M |
| Overall Score | 80.9 | 67.01 |
| Benchmarks Covered | 18 | 23 |
| Pricing (input/output) | $10.00 / $50.00 | $2.00 / $6.00 |

## Category Breakdown

### Agentic

- Winner: Claude Fable 5
- Claude Fable 5 public-lane score: 74.8 (Supported · #3/151)
- Grok 4.20 public-lane score: 26.5 (Supported · #144/151)

| Benchmark | Claude Fable 5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 34.0% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 84.3% | 47.1% | Claude Fable 5 |
| OSWorld-Verified | 85% | Coming soon | Coming soon |
| Terminal-Bench 2.1 (Vals) | 80.5% | 44.2% | Claude Fable 5 |
| DeepSearchQA | Coming soon | 62.8% | Coming soon |
| Gert Labs | Coming soon | 38.36% | Coming soon |

### Coding

- Winner: Claude Fable 5
- Claude Fable 5 public-lane score: 76.9 (Supported · #2/183)
- Grok 4.20 public-lane score: 28.2 (Supported · #171/183)

| Benchmark | Claude Fable 5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 95% | 76.7% | Claude Fable 5 |
| SWE-bench Pro | 80% | 51.8% | Claude Fable 5 |
| FrontierSWE v2 | 48.0% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | 53.5% | Coming soon | Coming soon |
| Terminal-Bench 2.0 | 84.3% | Coming soon | Coming soon |
| cursorBench31 | 70.6% | Coming soon | Coming soon |
| cursorBench32 | 70.5% | Coming soon | Coming soon |
| VulcanBench v3 | 89.5% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 89.8% | 84.3% | Claude Fable 5 |
| SWE-bench (Vals) | 95.0% | 72.2% | Claude Fable 5 |
| LiveCodeBench Pro | Coming soon | 74.2% | Coming soon |
| Vibe Code Bench | Coming soon | 4.06% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Claude Fable 5 public-lane score: 62.5 (Unranked · 2 rankable rows)
- Grok 4.20 public-lane score: 34.6 (#43/48)

| Benchmark | Claude Fable 5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| Blueprint-Bench 2 | 38.6% | Coming soon | Coming soon |
| OfficeQA Pro | 57.9% | Coming soon | Coming soon |
| 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 Fable 5 public-lane score: 76.2 (#11/22)
- Grok 4.20 public-lane score: 34.2 (Unranked · 2 rankable rows)

| Benchmark | Claude Fable 5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | Coming soon | 53.3% | Coming soon |
| ARC-AGI-3 | Coming soon | 0.1% | Coming soon |

### Knowledge

- Winner: Claude Fable 5
- Claude Fable 5 public-lane score: 83.5 (Supported · #2/181)
- Grok 4.20 public-lane score: 48.7 (Supported · #97/181)

| Benchmark | Claude Fable 5 | Grok 4.20 | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 93.2% | 88.6% | Claude Fable 5 |
| MMLU-Pro (Vals) | 91.5% | 86.3% | Claude Fable 5 |
| 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 |

### Instruction Following

- Winner: Coming soon
- Claude Fable 5 public-lane score: 78.3 (#54/120)
- Grok 4.20 public-lane score: Coming soon

## FAQ

### Which is better overall, Claude Fable 5 or Grok 4.20?

Claude Fable 5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Fable 5 and Grok 4.20?

The widest category gap is in coding, where the averages are 76.9 for Claude Fable 5 and 28.2 for Grok 4.20.

### How many benchmarks does Claude Fable 5 cover on BenchLM?

Claude Fable 5 currently has 18 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 Fable 5 vs Claude Fable 5.1](/compare/claude-fable-vs-claude-fable-5-1)
- [Grok 4.20 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-grok-4-20-beta)
- [Claude Fable 5 vs Grok 4.20 Multi-agent](/compare/claude-fable-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 Fable 5 profile](/models/claude-fable)
- [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)