LLM Reference

Claude Fable 5 vs Claude Sonnet 4.6

Claude Fable 5 (2026) and Claude Sonnet 4.6 (2026) are frontier-tier reasoning models from Anthropic. Claude Fable 5 ships a 1m-token context window, while Claude Sonnet 4.6 ships a 1m-token context window. On SWE-bench Verified, Claude Fable 5 leads by 16.4 pts. On pricing, Claude Sonnet 4.6 costs $3/1M input tokens versus $10/1M for the alternative. This comparison covers specs, pricing, API access, capabilities, benchmarks, input and output token costs, and production fit for coding and agent workloads.

Claude Sonnet 4.6 is ~233% cheaper at $3/1M; pay for Claude Fable 5 only for vision-heavy evaluation.

Decision scorecard

Local evidence first
SignalClaude Fable 5Claude Sonnet 4.6
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$15/1M tokens
Provider routes4 tracked6 tracked
Shared benchmarksSWE-bench Verified leader1 rows

Decision tradeoffs

Choose Claude Fable 5 when...
  • Claude Fable 5 holds a shared-benchmark lead on SWE-bench Verified, ahead by 16.4 points.
  • Local decision data tags Claude Fable 5 for Coding, RAG, and Agents.
Choose Claude Sonnet 4.6 when...
  • Claude Sonnet 4.6 has the lower cheapest tracked output price at $15/1M tokens.
  • Claude Sonnet 4.6 has broader tracked provider coverage for fallback and procurement flexibility.
  • Claude Sonnet 4.6 uniquely exposes Code execution, Computer use, and Parallel agents in local model data.
  • Local decision data tags Claude Sonnet 4.6 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 Sonnet 4.6

Claude Fable 5

$20,500

Cheapest tracked route/tier: Anthropic

Claude Sonnet 4.6

$6,150

Cheapest tracked route/tier: OpenRouter

Estimated monthly gap: $14,350. Batch, cache, alternate speed tiers, and negotiated pricing are excluded from this local estimate.

Switch friction

Claude Fable 5 -> Claude Sonnet 4.6
  • Provider overlap exists on Anthropic, AWS Bedrock, and GCP Vertex AI; start route-level A/B tests there.
  • Claude Sonnet 4.6 is $35/1M tokens lower on cheapest tracked output pricing before cache, batch, or negotiated discounts.
  • Claude Sonnet 4.6 adds Code execution, Computer use, and Parallel agents in local capability data.
Claude Sonnet 4.6 -> 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 $35/1M tokens higher on cheapest tracked output pricing, so quality gains need to justify the spend.
  • Check replacement coverage for Code execution, Computer use, and Parallel agents before moving production traffic.

Specs

Specification
Released2026-06-092026-02-17
Context window1m1m
Parameters
Architecturedecoder onlydecoder only
LicenseProprietaryProprietary
OpennessProprietaryProprietary
Commercial useCommercial use with conditionsCommercial use with conditions
Knowledge cutoff-2025-12

Pricing and availability

Pricing attributeClaude Fable 5Claude Sonnet 4.6
Input price$10/1M tokens$3/1M tokens
Output price$50/1M tokens$15/1M tokens
Providers

Capabilities

CapabilityClaude Fable 5Claude Sonnet 4.6
VisionYesYes
MultimodalYesYes
ReasoningYesYes
Function callingYesYes
Tool useYesYes
Structured outputsYesYes
Code executionNoYes
IDE integrationNoNo
Computer useNoYes
Parallel agentsNoYes

Benchmarks

BenchmarkClaude Fable 5Claude Sonnet 4.6
SWE-bench Verified96.079.6

Deep dive

On shared benchmark coverage, SWE-bench Verified has Claude Fable 5 at 96 and Claude Sonnet 4.6 at 79.6, with Claude Fable 5 ahead by 16.4 points. The largest visible gap is 16.4 points on SWE-bench Verified, which matters most when that benchmark mirrors your workload. Treat isolated benchmark wins as directional, because provider routing, prompt style, and tool access can move real application results.

The capability footprint differs most on code execution: Claude Sonnet 4.6. Both models share vision, multimodal input, reasoning mode, and function calling, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.

For cost, Claude Fable 5 lists $10/1M input and $50/1M output tokens on the cheapest tracked provider, while Claude Sonnet 4.6 lists $3/1M input and $15/1M output tokens on the cheapest tracked provider. A 70/30 input-output blend puts Claude Sonnet 4.6 lower by about $15.40 per million blended tokens. Availability is 4 providers versus 6, so concentration risk also matters.

Choose Claude Fable 5 when vision-heavy evaluation are central to the workload. Choose Claude Sonnet 4.6 when coding workflow support, lower input-token cost, and broader provider choice are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship.

FAQ

Which has a larger context window, Claude Fable 5 or Claude Sonnet 4.6?

Claude Fable 5 supports 1m tokens, while Claude Sonnet 4.6 supports 1m tokens. That gap matters most for long documents, large codebases, retrieval-heavy agents, and conversations where earlier context must remain visible.

Which is cheaper, Claude Fable 5 or Claude Sonnet 4.6?

Claude Sonnet 4.6 is cheaper on tracked token pricing. Claude Fable 5 costs $10/1M input and $50/1M output tokens. Claude Sonnet 4.6 costs $3/1M input and $15/1M output tokens. Provider discounts or batch pricing can still change the final bill.

Is Claude Fable 5 or Claude Sonnet 4.6 open source?

Claude Fable 5 is listed under Proprietary. Claude Sonnet 4.6 is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.

Which is better for vision, Claude Fable 5 or Claude Sonnet 4.6?

Both Claude Fable 5 and Claude Sonnet 4.6 expose vision. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Which is better for multimodal input, Claude Fable 5 or Claude Sonnet 4.6?

Both Claude Fable 5 and Claude Sonnet 4.6 expose multimodal input. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface.

Where can I run Claude Fable 5 and Claude Sonnet 4.6?

Claude Fable 5 is available on Anthropic, AWS Bedrock, GCP Vertex AI, and Microsoft Foundry. Claude Sonnet 4.6 is available on OpenRouter, Anthropic, AWS Bedrock, GCP Vertex AI, and Microsoft Foundry. Provider coverage can affect latency, region availability, compliance posture, and fallback options.

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Last reviewed: 2026-06-09. Data sourced from public model cards and provider documentation.