Claude Fable 5.1 vs Claude Sonnet 5
Why this pair: Newest generally available Claude model versus the current Sonnet tier
Benchmark Performance
Available Benchmarks
Technical Differences
Side-by-Side Facts
| Field | Claude Fable 5.1 | Claude Sonnet 5 |
|---|---|---|
| Developer | Anthropic | Anthropic |
| Family | Claude 5 1 | Claude 5 |
| Model | Claude Fable 5.1 | Claude Sonnet 5 |
| Version | Claude Fable 5.1 | Claude Sonnet 5 |
| Lifecycle | active | active |
| Released | 2026-09-01 | 2026-06-30 |
| Knowledge cutoff | 2026-06-01 | Unknown |
| Input modalities | Text, Image | Text, Image |
| Output modalities | Text | Text |
| Context window | 1,000,000 | 1,000,000 |
| 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 | Unknown | Anthropic (Standard), Deepinfra (Standard), Openrouter (Standard) |
| Capabilities | chat, generation, reasoning, tools | chat, generation, reasoning, tools |
13 comparable fields · 4 material differences · Editorially curated pair passes the primary-source comparison gate
Claude Fable 5.1 Capabilities
Claude Sonnet 5 Capabilities
Internal Comparison Graph
Related Comparisons
| A | Pair | B | Context |
|---|---|---|---|
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Claude Fable 5.1Anthropic | vs | Claude Opus 5Anthropic | family variantsimage, text |
Claude Mythos 5.1Anthropic | vs | Claude Sonnet 5Anthropic | family variantsimage, text |
Claude Fable 5.1Anthropic | vs |  GPT-5.6 SolOpenAI | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs |  Gemini 3.1 ProGoogle DeepMind | cross-developer peerstext |
Claude Fable 5.1Anthropic | vs | Grok 4.6xAI | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs |  Kimi-K3Moonshot AI | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs |  DeepSeek-V4-Flash-Vision-ExpDeepSeek | cross-developer peersimage, text |
Claude Fable 5.1Anthropic | vs |  Hy4 previewTencent | cross-developer peerstext |
Claude Opus 4.8Anthropic | vs | Claude Sonnet 5Anthropic | family variantsimage, text |
Claude Opus 5Anthropic | vs | Claude Sonnet 5Anthropic | family variantsimage, text |
Claude Fable 5.1Anthropic | vs | Claude Haiku 4.5Anthropic | family variantsimage, text |
Primary Evidence
Sources and Freshness
Questions
Claude Fable 5.1 vs Claude Sonnet 5 FAQs
Is Claude Fable 5.1 or Claude Sonnet 5 better for coding?+
This comparison does not currently contain a protocol-matched coding benchmark for both Claude Fable 5.1 and Claude Sonnet 5, so Model Markets cannot name a coding leader from pricing, context size, or capability labels alone.
Which is cheaper, Claude Fable 5.1 or Claude Sonnet 5?+
Only Claude Sonnet 5 has a directly sourced input price: $2.00 per million tokens. Only Claude Sonnet 5 has a directly sourced output price: $10.00 per million tokens.
Which has a larger context window, Claude Fable 5.1 or Claude Sonnet 5?+
Neither model has a larger sourced context window in this comparison. Claude Fable 5.1 is 1,000,000 and Claude Sonnet 5 is 1,000,000.
Which performs better in benchmarks, Claude Fable 5.1 or Claude Sonnet 5?+
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 Claude Sonnet 5 be self-hosted?+
Both models have the same recorded self-hosting status: unsupported. Claude Fable 5.1 is not marked open weight; Claude Sonnet 5 is not marked open weight.
Can Claude Fable 5.1 and Claude Sonnet 5 understand images?+
Claude Fable 5.1 is documented with image input; Claude Sonnet 5 is documented with image input. This reflects supported input modalities, not vision quality.
Which can generate longer answers, Claude Fable 5.1 or Claude Sonnet 5?+
Neither has a larger sourced maximum output. Claude Fable 5.1 is 128,000 and Claude Sonnet 5 is 128,000.
Do Claude Fable 5.1 and Claude Sonnet 5 support reasoning and tool use?+
Claude Fable 5.1: reasoning, tool calling, and image input. Claude Sonnet 5: reasoning, tool calling, and image input. Feature support does not establish relative quality.
Which is available from more inference providers, Claude Fable 5.1 or Claude Sonnet 5?+
Claude Fable 5.1 has 0 sourced provider routes; Claude Sonnet 5 has 3, so Claude Sonnet 5 has broader tracked availability.
Which offers better value, Claude Fable 5.1 or Claude Sonnet 5?+
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.