# Claude Fable 5 vs Claude Opus 4.8

> Side-by-side benchmark comparison for Claude Fable 5 and Claude Opus 4.8 across agentic, coding, multimodal, knowledge, reasoning, multilingual, and math tasks.

- Canonical page: https://benchlm.ai/compare/claude-fable-vs-claude-opus-4-8
- Last updated: September 4, 2026

- Shared sourced benchmarks: 15
- HTML indexing: indexable
- Ranking lane: BenchAlign v5

## Quick Verdict

Pick Claude Fable 5 if you want the stronger benchmark profile. Claude Opus 4.8 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 72.3.
- The clearest category separation is in multimodal & grounded, where the averages are 62.5 for Claude Fable 5 and 87.8 for Claude Opus 4.8.
- The biggest single benchmark swing is Terminal-Bench 3.0 in Agentic, with scores of 34.0% and 21.1%.
- Claude Opus 4.8 is the cheaper option on output tokens, which matters if you expect large responses or heavy interactive use.

## Model Snapshot

| Property | Claude Fable 5 | Claude Opus 4.8 |
|----------|----------|----------|
| Creator | Anthropic | Anthropic |
| Type | Proprietary | Proprietary |
| Reasoning | Reasoning | Reasoning |
| Context | 1M+ | 1M |
| Overall Score | 80.9 | 72.3 |
| Benchmarks Covered | 18 | 38 |
| Pricing (input/output) | $10.00 / $50.00 | $5.00 / $25.00 |

## Category Breakdown

### Agentic

- Winner: Claude Fable 5
- Claude Fable 5 public-lane score: 74.8 (Supported · #3/151)
- Claude Opus 4.8 public-lane score: 63.2 (Supported · #16/151)

| Benchmark | Claude Fable 5 | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| Terminal-Bench 3.0 | 34.0% | 21.1% | Claude Fable 5 |
| Terminal-Bench 2.0 | 84.3% | 74.6% | Claude Fable 5 |
| OSWorld-Verified | 85% | 83.4% | Claude Fable 5 |
| Terminal-Bench 2.1 (Vals) | 80.5% | 71.9% | Claude Fable 5 |
| BrowseComp | Coming soon | 84.3% | Coming soon |
| DeepSearchQA | Coming soon | 93.1% | Coming soon |
| Finance Agent v2 | Coming soon | 53.9% | Coming soon |
| MCP Atlas | Coming soon | 82.2% | Coming soon |
| Toolathlon | Coming soon | 59.9% | Coming soon |
| Gert Labs | Coming soon | 72.97% | Coming soon |
| ResearchClawBench | Coming soon | 21.1% | Coming soon |
| OSWorld 2.0 | Coming soon | 20.6% | Coming soon |

### Coding

- Winner: Claude Fable 5
- Claude Fable 5 public-lane score: 76.9 (Supported · #2/183)
- Claude Opus 4.8 public-lane score: 66.5 (Supported · #12/183)

| Benchmark | Claude Fable 5 | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| SWE-bench Verified | 95% | 88.6% | Claude Fable 5 |
| SWE-bench Pro | 80% | 69.2% | Claude Fable 5 |
| FrontierSWE v2 | 48.0% | Coming soon | Coming soon |
| FrontierCode 1.1 Main | 53.5% | 46.5% | Claude Fable 5 |
| Terminal-Bench 2.0 | 84.3% | 74.6% | Claude Fable 5 |
| cursorBench31 | 70.6% | 58.4% | Claude Fable 5 |
| cursorBench32 | 70.5% | 62.3% | Claude Fable 5 |
| VulcanBench v3 | 89.5% | Coming soon | Coming soon |
| LiveCodeBench (Vals) | 89.8% | 87.8% | Claude Fable 5 |
| SWE-bench (Vals) | 95.0% | 88.6% | Claude Fable 5 |
| SWE Multilingual | Coming soon | 84.4% | Coming soon |
| SWE Multimodal | Coming soon | 38.4% | Coming soon |

### Multimodal & Grounded

- Winner: Coming soon
- Claude Fable 5 public-lane score: 62.5 (Unranked · 2 rankable rows)
- Claude Opus 4.8 public-lane score: 87.8 (#3/48)

| Benchmark | Claude Fable 5 | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| Blueprint-Bench 2 | 38.6% | Coming soon | Coming soon |
| OfficeQA Pro | 57.9% | 66.2% | Claude Opus 4.8 |
| ScreenSpot Pro | Coming soon | 87.9% | Coming soon |
| CharXiv | Coming soon | 89.9% | Coming soon |
| CharXiv w/o tools | Coming soon | 80.5% | Coming soon |

### Reasoning

- Winner: Coming soon
- Claude Fable 5 public-lane score: 76.2 (#11/22)
- Claude Opus 4.8 public-lane score: 55.1 (#20/22)

| Benchmark | Claude Fable 5 | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| ARC-AGI-2 | Coming soon | 72.1% | Coming soon |
| ARC-AGI-3 | Coming soon | 1.5% | Coming soon |

### Knowledge

- Winner: Claude Fable 5
- Claude Fable 5 public-lane score: 83.5 (Supported · #2/181)
- Claude Opus 4.8 public-lane score: 71.7 (Supported · #9/181)

| Benchmark | Claude Fable 5 | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| GPQA Diamond (Vals) | 93.2% | 92.4% | Claude Fable 5 |
| MMLU-Pro (Vals) | 91.5% | 89.6% | Claude Fable 5 |
| GPQA | Coming soon | 93.6% | Coming soon |
| GPQA-D | Coming soon | 93.6% | Coming soon |
| HLE | Coming soon | 57.9% | Coming soon |
| HLE w/o tools | Coming soon | 49.8% | Coming soon |

### Instruction Following

- Winner: Coming soon
- Claude Fable 5 public-lane score: 78.3 (#54/120)
- Claude Opus 4.8 public-lane score: 75.2 (#59/120)

### Multilingual

- Winner: Coming soon
- Claude Fable 5 public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: Coming soon

| Benchmark | Claude Fable 5 | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| INCLUDE | Coming soon | 87.6% | Coming soon |

### Mathematics

- Winner: Coming soon
- Claude Fable 5 public-lane score: Coming soon
- Claude Opus 4.8 public-lane score: 65.4 (#2/7)

| Benchmark | Claude Fable 5 | Claude Opus 4.8 | Winner |
|-----------|-----------|-----------|--------|
| USAMO 2026 | Coming soon | 96.7% | Coming soon |
| FrontierMath v2 (Tiers 1-3) | Coming soon | 47.241% | Coming soon |
| FrontierMath v2 (Tier 4) | Coming soon | 31.250% | Coming soon |

## FAQ

### Which is better overall, Claude Fable 5 or Claude Opus 4.8?

Claude Fable 5 is ahead overall on BenchLM right now.

### Where is the biggest gap between Claude Fable 5 and Claude Opus 4.8?

The widest category gap is in multimodal & grounded, where the averages are 62.5 for Claude Fable 5 and 87.8 for Claude Opus 4.8.

### 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 Claude Opus 4.8 cover on BenchLM?

Claude Opus 4.8 currently has 38 sourced benchmark scores on BenchLM.

## Related Comparisons

- [Claude Fable 5 vs Claude Fable 5.1](/compare/claude-fable-vs-claude-fable-5-1)
- [Claude Opus 4.8 vs Claude Fable 5.1](/compare/claude-fable-5-1-vs-claude-opus-4-8)
- [Claude Fable 5 vs GPT-6 Astra](/compare/claude-fable-vs-gpt-6-astra)
- [Claude Opus 4.8 vs GPT-6 Astra](/compare/claude-opus-4-8-vs-gpt-6-astra)

## Explore More

- [Claude Fable 5 profile](/models/claude-fable)
- [Claude Opus 4.8 profile](/models/claude-opus-4-8)
- [Compare Pricing](/llm-pricing)
- [Alternative Finder](/tools/alternative-finder)
- [LLM Selector](/tools/llm-selector)
- [Overall Rankings](/best/overall)