# Claude Fable 5 vs Claude Opus 4.8 (2026): Benchmarks, Price & Verdict | Alher Tech

> Claude Fable 5 vs Claude Opus 4.8: head-to-head 2026 comparison across Arena Elo, MMLU, GPQA, HumanEval, context window and pricing. Verdict + use cases.

- Canonical page: https://alhertech.com/en/ai-comparison/claude-fable-5-vs-claude-opus-4-8/
- Site: Alher Tech (custom software, AI agents and SEO engineering, https://alhertech.com/)
- Contact: https://alhertech.com/en/contact/

---

|  | Claude Fable 5 | Claude Opus 4.8 |
| --- | --- | --- |
| arenaElo | 1492 | 1435 |
| humanEval | 98 | 94.5 |
| sweBench | 77 | 67 |
| mmlu | 95.1 | 93 |
| gpqa | 92 | 67.5 |
| aime | 94 | 90 |
| Price in/out ($/M) | $10 / $50 | $5 / $25 |

## Our verdict

Fable 5 is the most capable model Anthropic ships (stronger long-horizon autonomous agents and frontier reasoning), but it costs $10 / $50 per M tokens, uses a new tokenizer that counts ~30% more tokens, has thinking always on, and requires 30-day data retention. Opus 4.8 stays the pragmatic default at $5 / $25 with the familiar request surface. Reach for Fable 5 on your hardest agentic and research work; keep Opus 4.8 for the high-volume bulk of production traffic.

[Claude Fable 5](https://alhertech.com/en/ai-comparison/claude-fable-5/) · [Claude Opus 4.8](https://alhertech.com/en/ai-comparison/claude-opus-4-8/) · [All AI model comparisons](https://alhertech.com/en/ai-comparison/)