Claude Fable 5.1 vs Sonar Reasoning Pro
At a Glance
| Compare | Claude Fable 5.1Anthropic |  Sonar Reasoning ProPerplexity |
|---|---|---|
| Intelligence, Cost, and Efficiency | ||
| IntelligenceHigher is better · MM Intelligence v2.5 | #1 of 4699.0 score · 3/3 sources · complete | UnrankedNot in the 46-model eligible cohort |
| CostLower is better · Published-token output estimate | #43 of 44$0.824 per LiveBench case | UnrankedNot in the 44-model eligible cohort |
| EfficiencyHigher is better · MM Efficiency v1.5 | #22 of 3851.7 score · 3/3 sources · complete | UnrankedNot in the 38-model eligible cohort |
| Pricing and Limits | ||
| Input priceFrom · USD / 1M tokens | $10.00Anthropic ↗ · Sep 3, 2026 | $2.00Openrouter ↗ · Sep 22, 2026 |
| Output priceFrom · USD / 1M tokens | $50.00Anthropic ↗ · Sep 3, 2026 | $8.00Openrouter ↗ · Sep 22, 2026 |
| Context windowMaximum documented tokens | 1,000K | 128K |
| Model facts checked | Sep 2, 2026View model evidence → | Aug 29, 2026View model evidence → |
Token prices are the lowest available sourced USD rates; input and output may use different providers. Cost ranking estimates output spend on LiveBench, not a full request bill. Ranking methodology →
Available Benchmarks
Side-by-Side Facts
| Field | Claude Fable 5.1 | Sonar Reasoning Pro |
|---|---|---|
| Developer | Anthropic | Perplexity |
| Family | Claude 5 1 | Sonar |
| Model | Claude Fable 5.1 | Sonar Reasoning Pro |
| Version | Claude Fable 5.1 | Sonar Reasoning Pro |
| Lifecycle | active | active |
| Released | 2026-09-01 | Unknown |
| Knowledge cutoff | 2026-06-01 | Unknown |
| Input modalities | Text, Image | Text |
| Output modalities | Text | Text |
| Context window | 1,000K | 128K |
| Total parameters | Unknown | Unknown |
| Active parameters | Unknown | Unknown |
| License | Unknown | Unknown |
| Open weights | No | No |
| API available | Yes | Yes |
| Self-hostable | No | No |
| Provider access | Anthropic (Standard) | Openrouter (Standard), Perplexity (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, citations, reasoning, search |
Claude Fable 5.1 Capabilities
Sonar Reasoning Pro Capabilities
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Primary Evidence
Sources and Freshness
Questions
Claude Fable 5.1 vs Sonar Reasoning Pro FAQs
Is Claude Fable 5.1 or Sonar Reasoning Pro better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Fable 5.1 and Sonar Reasoning Pro, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Fable 5.1 or Sonar Reasoning Pro?+
Claude Fable 5.1 is $10.00 and Sonar Reasoning Pro is $2.00 per million tokens, so Sonar Reasoning Pro is cheaper on this metric. Claude Fable 5.1 is $50.00 and Sonar Reasoning Pro is $8.00 per million tokens, so Sonar Reasoning Pro is cheaper on this metric.
Which has a larger context window, Claude Fable 5.1 or Sonar Reasoning Pro?+
Claude Fable 5.1 has the larger sourced context window. Claude Fable 5.1 supports 1,000K and Sonar Reasoning Pro supports 128K.
Which performs better in benchmarks, Claude Fable 5.1 or Sonar Reasoning Pro?+
There is no overall benchmark winner: At least two independently verified, protocol-matched benchmarks are required for an overall winner.
Can Claude Fable 5.1 or Sonar Reasoning Pro be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Fable 5.1 is not marked open weight; Sonar Reasoning Pro is not marked open weight.
Can Claude Fable 5.1 and Sonar Reasoning Pro understand images?+
Claude Fable 5.1 is documented with image input; Sonar Reasoning Pro is not documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Fable 5.1 or Sonar Reasoning Pro?+
Neither has a larger sourced maximum output. Claude Fable 5.1 is 128K and Sonar Reasoning Pro is —.
Do Claude Fable 5.1 and Sonar Reasoning Pro support reasoning and tool use?+
Claude Fable 5.1: reasoning, tool calling, and image input. Sonar Reasoning Pro: reasoning. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Fable 5.1 or Sonar Reasoning Pro?+
Claude Fable 5.1 has 1 sourced provider route; Sonar Reasoning Pro has 2, so Sonar Reasoning Pro has broader tracked availability.
Which offers better value, Claude Fable 5.1 or Sonar Reasoning Pro?+
There is no universal value winner. Compare the input and output prices above with the matched benchmark result for your workload: cheaper tokens can be offset by different quality, token usage, latency, or provider availability.