Claude Fable 5.1 — Specifications
Compiled by Mustafa Ihsan from the vendor’s published documentation · Last updated
| Desenvolvedor | Anthropic |
|---|---|
| Tipo | Raciocínio / agente |
| Modalidade | Texto, visão |
| Parâmetros | Não divulgado |
| Janela de contexto | 1 milhão |
| Saída máxima | 128K |
| Licença | Proprietário |
| Pesos abertos | Não |
| Lançado | 2026-09 |
| Preço da entrada | $10.00 /1M |
| Preço da saída | $50.00 /1M |
| Provedores de API | Anthropic API, AWS, Google Cloud, Microsoft Azure |
Benchmarks
| Anthropic-reported | Terminal-Bench 4.0 55.8%; GDPval-AA v2 1853 Elo; OSWorld 2.0 (partial) 77.9%; Humanity's Last Exam 60.9% (no tools), 65.0% (with tools); CursorBench 3.2.0 73.4%; AutomationBench 31.4%. Cache reads $0.25 per 1M tokens. |
|---|
What is Claude Fable 5.1?
Claude Fable 5.1 is Anthropic’s most capable generally available model, released on 1 September 2026 as an update to Claude Fable 5. De acordo com Anthropic, it is aimed at demanding reasoning and long-running agentic work: coding, multistep research, and document, spreadsheet and slide tasks. Claude Mythos 5.1 is the same model with different safeguards, offered only to organisations in Anthropic’s verification programmes.
API pricing is the same as Fable 5: $10 per million input tokens and $50 per million output tokens. Cache reads fell 75% to $0.25 per million, which Anthropic estimates makes typical workloads about 25% cheaper. It has a 1M-token context window and up to 128K output tokens, and runs on the Claude API as claude-fable-5-1 and on AWS, Google Cloud and Microsoft Azure.
For most work Anthropic now recommends starting with the cheaper Claude Opus 5.5 ($4 / $20) and moving to Fable 5.1 only when that falls short. Launch details are in our Fable 5.1 release story, and the Calculadora de custos de API de IA compares monthly costs.
Claude Fable 5.1 pricing: API cost per 1M tokens
| Entrada (por 1 milhão de tokens) | $10.00 |
|---|---|
| Saída (por 1 milhão de tokens) | $50.00 |
| Razão saída/entrada | 5× |
| Misturada (4:1 entrada:saída) | $18.00 por 1 milhão de tokens |
What Claude Fable 5.1 costs per month
Gasto mensal real com uma proporção de entrada para saída de 4:1 — a razão efetivamente gerada por cargas de trabalho típicas de chat ou RAG.
| Carga de trabalho | Tokens/mês | Custo por mês |
|---|---|---|
| Projeto paralelo | 1 milhão de tokens de entrada / 0,25 milhão de tokens de saída | $23 |
| Equipe pequena | 20 milhões de tokens de entrada / 5 milhões de tokens de saída | $450 |
| Produção | 200 milhões de tokens de entrada / 50 milhões de tokens de saída | $4,500 |
Calcule seus próprios números na Calculadora de custos de API de IA.
Cheaper alternatives to Claude Fable 5.1
| Modelo | Custo médio ponderado por US$ 1 milhão | Você economiza |
|---|---|---|
| Mistral 7B aberta | $0.0220 | 100% mais barato |
| Llama 3.1 8B aberta | $0.0220 | 100% mais barato |
| Mistral NeMo 12B aberta | $0.0240 | 100% mais barato |
Perguntas frequentes
How much does Claude Fable 5.1 cost per 1M tokens?
Claude Fable 5.1 costs $10.00 per 1M input tokens and $50.00 per 1M output tokens. At a typical 4:1 input-to-output mix that blends to about $18.00 per 1M tokens.
How much does Claude Fable 5.1 cost per month?
A small-team workload of 20M input and 5M output tokens a month costs about $450 on Claude Fable 5.1. A side project (1M in / 0.25M out) costs roughly $22.50.
What is a cheaper alternative to Claude Fable 5.1?
Mistral 7B is the strongest cheaper option in our database at $0.0220 per 1M blended — about 100% less than Claude Fable 5.1. It is also open-weight, so self-hosting is an option.
Can I run Claude Fable 5.1 locally?
No. Claude Fable 5.1 is a closed, API-only model — the weights are not released, so it cannot be self-hosted.
Why does Claude Fable 5.1 charge more for output than input?
Output tokens are generated one at a time and cannot be batched the way a prompt can, so they cost the provider more to serve. Claude Fable 5.1 charges 5× more for output, which is why prompt-heavy workloads are far cheaper to run than generation-heavy ones.
Veja todos os modelos Claude com preços comparados lado a lado: Preços da API Claude.
Os preços correspondem às tarifas listadas oficialmente para a API principal do modelo e são revisados conforme os provedores os atualizam. Descontos por volume, processamento em lote ou entradas em cache não estão incluídos. Compare todos os modelos lado a lado na Banco de dados de modelos de IA ou o Ranking de LLMs.