Claude Fable 5 vs Claude Opus 4.8: pricing, Quality, Value, and benchmarks

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Pricing, app access, and Conversation Value

• Humanity's Last Exam

  Normalized quality input

  53.3%

  Artificial Analysis Claude Fable 5 evaluation | Independent Fable 5 production-config result with adaptive reasoning, maximum effort, and Opus 4.8 fallback.

• AA-Omniscience

  AA-Omniscience Index

  40.1

  Artificial Analysis AA-Omniscience evaluation | Independent Artificial Analysis result for Claude Fable 5 (Adaptive Reasoning, Max Effort, Opus 4.8 Fallback). Display-only; this row does not affect Quality or Value scores.

• SWE-Bench Pro

  Normalized quality input

  80.0%

  Anthropic Claude Fable 5 and Mythos 5 system card | Anthropic vendor-reported Fable 5 result averaged over five trials. Use the Fable 5 SWE-Bench Pro column, not Mythos 5 or SWE-Bench Verified.

• Terminal-Bench 2.1

  Multi-file coding

  84.3%

  Anthropic Claude Fable 5 and Mythos 5 system card | Anthropic vendor-reported Fable 5 Terminal-Bench 2.1 result using mini-SWE-agent at high effort; 20.9% of trials fell back to Opus 4.8.

• Humanity's Last Exam

  Normalized quality input

  49.8%

  Anthropic Claude Opus 4.8 release page | Vendor-reported Anthropic Opus 4.8 HLE no-tools score. Do not replace with tools-enabled or adaptive-effort HLE variants.

• SWE-Bench Pro

  Software engineering task resolution

  69.2%

  Anthropic Claude Opus 4.8 release page | Vendor-reported Anthropic Opus 4.8 SWE-Bench Pro score. Do not substitute SWE-Bench Verified.

• AA-Omniscience

  AA-Omniscience Index

  27.4

  Artificial Analysis AA-Omniscience evaluation | Independent Artificial Analysis result for Claude Opus 4.8 (Adaptive Reasoning, Max Effort). Display-only; this row does not affect Quality or Value scores.

The most intelligent model in the current field, but its record capability comes with roster-leading token prices, quarter-rate token throughput, and safeguard-triggered Opus 4.8 fallback.

Claude Fable 5 is the most intelligent generally available model in the current field: its production configuration leads the independent Artificial Analysis Intelligence Index, while Anthropic reports 80.0% on SWE-Bench Pro and 84.3% on Terminal-Bench 2.1. Buy it selectively, not by default. At $10 per million input tokens and $50 per million output tokens, it is the most expensive model in the current PickAI roster, and its published input and output token-per-minute limits are only one quarter of Opus 4.x and Sonnet 5. Fable can also decline classifier-flagged requests involving cybersecurity, biology or chemistry, model distillation, or frontier-AI development; supported Claude clients may then serve the request with Opus 4.8. Anthropic says client users are notified and API responses identify the serving model or refusal, so production integrations should surface that metadata and never assume every Fable request was answered by Fable.

Claude Opus 4.8 is Anthropic's newest Opus model, strongest for coding, agentic tasks, and complex professional work where the vendor-reported benchmark evidence applies.

Released May 28, 2026, Claude Opus 4.8 is Anthropic's current flagship and its most capable publicly available model. It is best suited to complex agentic coding, legal and financial document analysis, deep multi-step reasoning, and long-running autonomous tasks. The meaningful upgrades over 4.7 are a dramatic improvement in mathematical reasoning, meaningfully better honesty (it flags its own mistakes rather than quietly moving on), and efficiency gains that mean it uses around 35% fewer output tokens to do the same work — so you actually get a little more for your money despite the unchanged rate card. The honest caveats: it is expensive at $25 per million output tokens, which adds up fast on any high-volume or long-session workflow. On claude.ai, users now have control over the amount of effort Claude puts into a task, but Pro plan rate limits are real and noticeable if you push it hard — heavy users will hit the ceiling. It is also slower than average at inference speed, so it thinks longer before responding. For chat, summarisation, and general Q&A, Sonnet 4.6 covers 90%+ of workloads at 40% lower per-token cost — most buyers do not need Opus for everyday tasks. AnthropicFinout Bottom line: Opus 4.8 is genuinely the best model for serious, sustained, complex work. It is overkill and quietly costly for anything routine — and if you hit the rate limits on a Pro plan, the frustration will feel disproportionate to what you are paying.