Claude Fable 5 vs Claude Sonnet 4.5
Claude Fable 5 (Anthropic) and Claude Sonnet 4.5 (Anthropic) compared on benchmarks, pricing, context window, and use-case rankings.
- Claude Fable 5 leads on overall intelligence (ECI 163 vs 147).
- Claude Sonnet 4.5 is cheaper on input tokens — $3.00 vs $10.00 per 1M.
- Claude Fable 5 ranks higher for coding (96th vs 26th percentile).
| Attribute | Claude Fable 5 | Claude Sonnet 4.5 |
|---|---|---|
| Scores | ||
| Intelligence (ECI) | 163 | 147 |
| Coding | 96 | 26 |
| Math | 96 | 41 |
| Reasoning & Knowledge | 89 | 23 |
| Agentic & Tools | 96 | 17 |
| Specifications | ||
| Developer | Anthropic | Anthropic |
| Family | Claude | Claude |
| Released | Jun 9, 2026 | Sep 29, 2025 |
| Parameters | — | — |
| Availability | API access | API access |
| Context window | 1M | 1M |
| Price — $/M input | $10.00 | $3.00 |
| Price — $/M output | $50.00 | $15.00 |
| Inputs | text, image, file | text, image, file |
| Outputs | text | text |
| Benchmarks | ||
| AIME 2024/2025 | 100% | 78% |
| APEX | 45% | — |
| ARC-AGI | 99% | 64% |
| ARC-AGI-2 | 89% | 14% |
| GPQA Diamond | 86% | 82% |
| Humanity's Last Exam | 56% | 14% |
| SciCode | 61% | — |
| SimpleBench | 82% | 54% |
| SimpleQA Verified | 71% | 31% |
| WebDev Arena | 1626 | 1391 |
| WeirdML | 92% | 48% |
| τ²-bench | 99% | — |
| FrontierMath | — | 15% |
| FrontierMath Tier 4 | — | 4% |
| GDPval (win/tie rate) | — | 50% |
| GSO (code optimization) | — | 15% |
| MATH Level 5 | — | 98% |
| METR task horizon | — | 2.0 h |
| SWE-bench Verified | — | 71% |
| Terminal-Bench | — | 47% |
Use-case scores are 0–100 percentile composites across each area’s benchmarks, ranked against every model from the past year. Highlighted cells lead each row. Open a model for the full picture.
Frequently asked questions
Is Claude Fable 5 better than Claude Sonnet 4.5?
On Epoch AI's Capabilities Index, Claude Fable 5 scores higher (163) than Claude Sonnet 4.5 (147). The right pick depends on your task — compare their coding, math, and reasoning scores in the table above.
Which is cheaper, Claude Fable 5 or Claude Sonnet 4.5?
Claude Sonnet 4.5 is cheaper on input tokens at $3.00 per million, versus $10.00 (representative OpenRouter pricing).
Which has a larger context window, Claude Fable 5 or Claude Sonnet 4.5?
Claude Fable 5 supports up to 1M tokens, compared with 1M for the other.
Which is better for coding, Claude Fable 5 or Claude Sonnet 4.5?
Across coding benchmarks like SWE-bench Verified and Terminal-Bench, Claude Fable 5 ranks higher — 96th vs 26th percentile among the models tracked on Model Beat.
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Benchmarks & model data from Epoch AI (CC BY); pricing & specs from OpenRouter. ECI = Epoch Capabilities Index.