LLM Reference

Claude Fable 5 vs Claude Opus 5

Claude Opus 5 and Claude Fable 5 are Anthropic's current premium decision pair. Anthropic recommends Opus 5 as the starting point for complex agentic coding and enterprise work, while it positions Fable 5 for workloads that need the highest available capability. Both have 1M-token context windows and 128K synchronous output, but Opus 5's standard Claude API price is $5/M input and $25/M output versus Fable 5 at $10/M and $50/M.

Choose Claude Opus 5 when you want the premium everyday route for complex coding, long-running agents, and enterprise analysis at half Fable 5's standard token price. Evaluate Claude Fable 5 when the highest available capability is worth the higher price and its access and safeguard profile fits the workload. Neither model is a universal winner: use setting-matched evaluations and test the provider route, latency, safety behavior, and task mix you actually plan to deploy.

Decision scorecard

Local evidence first
SignalClaude Fable 5Claude Opus 5
Best forreasoning-heavy apps, multimodal apps, and tool-calling agentsreasoning-heavy apps, multimodal apps, and tool-calling agents
Decision fitCoding, RAG, and AgentsCoding, RAG, and Agents
Context window1m1m
Cheapest output$50/1M tokens$25/1M tokens
Provider routes8 tracked7 tracked
Shared benchmarks0 shared0 shared

Decision tradeoffs

Choose Claude Fable 5 when...
  • Claude Fable 5 has broader tracked provider coverage for fallback and procurement flexibility.
  • Local decision data tags Claude Fable 5 for Coding, RAG, and Agents.
Choose Claude Opus 5 when...
  • Claude Opus 5 has the lower cheapest tracked output price at $25/1M tokens.
  • Claude Opus 5 uniquely exposes Code execution and Computer use in local model data.
  • Local decision data tags Claude Opus 5 for Coding, RAG, and Agents.

Monthly cost at traffic

Estimate token spend from the cheapest tracked input and output route or tier on this page.

Lower estimate Claude Opus 5

Claude Fable 5

$20,500

Cheapest tracked route/tier: Anthropic

Claude Opus 5

$10,250

Cheapest tracked route/tier: Anthropic

Estimated monthly gap: $10,250. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Fable 5 -> Claude Opus 5
  • Provider overlap exists on Anthropic, AWS Bedrock, and GCP Vertex AI; start route-level A/B tests there.
  • Claude Opus 5 is $25/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Claude Opus 5 adds Code execution and Computer use in local capability data.
Claude Opus 5 -> Claude Fable 5
  • Provider overlap exists on Anthropic, AWS Bedrock, and GCP Vertex AI; start route-level A/B tests there.
  • Claude Fable 5 is $25/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Check replacement coverage for Code execution and Computer use before moving production traffic.

Specs

Specification
Released2026-06-092026-07-24
Context window1m1m
Parameters
ArchitectureDecoder OnlyDecoder Only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
WeightsNot releasedNot released
CodeUnknownNot released
Commercial useCommercial use: conditionalCommercial use: conditional
Knowledge cutoff-2026-05

Pricing and availability

Pricing attributeClaude Fable 5Claude Opus 5
Input price$10/1M tokens$5/1M tokens
Output price$50/1M tokens$25/1M tokens
Providers

Capabilities

CapabilityClaude Fable 5Claude Opus 5
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionNoYes
IDE integrationNoNo
Computer useNoYes
Parallel agentsNoNo

Benchmarks

No shared benchmark scores are currently available for this pair.

Deep dive

Price is the clearest documented split. Anthropic lists Opus 5 at $5/M input and $25/M output, while Fable 5 is $10/M and $50/M. Both offer 50% Batch API rates and prompt-cache discounts, so the two-to-one base-price relationship remains relevant for long agent loops and large-context workloads.

Headline limits are tied: both models have 1M context and 128K synchronous output. Fable 5's value case is therefore Anthropic's highest-capability positioning, not a larger window. On Opus 5, the effort parameter controls thinking volume and token use across five levels, with high as the default; it does not reliably control visible response length.

The curated head-to-head suppresses SWE-bench Pro and SWE-bench Verified because the available rows use different evaluators, harnesses, and settings. Use each model's benchmark page for its source-specific evidence rather than inferring a winner from incompatible measurements.

Provider coverage should be checked per route. Opus 5 is seeded across Anthropic API, Bedrock, Google Cloud, Microsoft Foundry, OpenRouter, Vercel AI Gateway, and Databricks, with blank prices where the provider did not publish them. Fable 5 has its own access history and safeguard behavior, so teams should confirm live availability instead of assuming the two models are interchangeable.

FAQ

Which is cheaper, Claude Opus 5 or Fable 5?

Claude Opus 5 is half the standard Claude API price: $5/M input and $25/M output versus Fable 5 at $10/M and $50/M. Both have separate batch and prompt-caching discounts.

Which model has more context?

Neither. Claude Opus 5 and Fable 5 are both documented with 1M-token context windows and 128K synchronous output limits.

Is Fable 5 always better than Opus 5?

No universal ranking is supported. Anthropic positions Fable 5 for the highest available capability and Opus 5 for complex agentic coding and enterprise work at the lower Opus price. Evaluate the exact workload and effort setting.

Can I compare their SWE-bench rows directly?

No. The available Opus 5 and Fable 5 rows use different evaluators, harnesses, and settings, so this head-to-head omits them. Review each result with its source-specific methodology instead.

Continue comparing

Last reviewed: 2026-07-26. Data sourced from public model cards and provider documentation.