Claude Fable 5.1 — Specifications
Compiled by Mustafa Ihsan from the vendor’s published documentation · Last updated
| Desarrollador | Anthropic |
|---|---|
| Tipo | Razonamiento / agente |
| Modalidad | Texto, visión |
| Parámetros | No revelado |
| Ventana de contexto | 1 millón |
| Salida máxima | 128 K |
| Licencia | Propietario |
| Pesos abiertos | No |
| Lanzado | 2026-09 |
| Precio de entrada | $10.00 /1M |
| Precio de salida | $50.00 /1M |
| Proveedores 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. Según 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 costos de API de IA compares monthly costs.
Claude Fable 5.1 pricing: API cost per 1M tokens
| Entrada (por cada millón de tokens) | $10.00 |
|---|---|
| Salida (por cada millón de tokens) | $50.00 |
| Relación salida/entrada | 5× |
| Combinada (4:1 entrada:salida) | $18.00 por 1 millón de tokens |
What Claude Fable 5.1 costs per month
Gasto mensual real con una mezcla entrada:salida de 4:1, es decir, la proporción que realmente genera una carga de trabajo típica de chat o RAG.
| Carga de trabajo | Tokens/mes | Coste mensual |
|---|---|---|
| Proyecto secundario | 1 millón de tokens de entrada / 0,25 millones de tokens de salida | $23 |
| Pequeño equipo | 20 millones de tokens de entrada / 5 millones de tokens de salida | $450 |
| Producción | 200 millones de tokens de entrada / 50 millones de tokens de salida | $4,500 |
Calcule sus propios números en la Calculadora de costos de API de IA.
Cheaper alternatives to Claude Fable 5.1
| Modelo | Dólares por millón combinados | Usted ahorra |
|---|---|---|
| Mistral 7B abierta | $0.0220 | 100 % más barato |
| Llama 3.1 8B abierta | $0.0220 | 100 % más barato |
| Mistral NeMo 12B abierta | $0.0240 | 100 % más barato |
Preguntas frecuentes
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.
Vea todos los modelos Claude comparados lado a lado: Precios de la API de Claude.
Los precios corresponden a las tarifas oficiales publicadas para la API principal del modelo y se revisan periódicamente conforme los proveedores los actualicen. No incluyen descuentos por volumen, procesamiento por lotes ni entradas en caché. Compare todos los modelos uno al lado del otro en la Base de datos de modelos de IA o el Clasificación de modelos de lenguaje grande (LLM).