Claude Fable 5.1
by Anthropictext+image+file->text4 endpoints
Neura Intelligence Index
96.6/ 100
Rank
#4—
Confidence
lowBenchmarks
1(3% coverage)
Overview
Claude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors, front-end and visual code generation, and finance and analysis tasks in particular. It also tends to be more concise than Fable 5 in its plans and summaries. We recommend testing it as a direct upgrade wherever you use Fable 5 today, and alongside Opus 5 on reasoning-heavy tasks.
Capabilities
Text generation
Image understanding
Tool use / Function calling
Structured output
Extended reasoning
Prompt caching
Long context
File input
Stop sequences
Modalities
Input
TextImageFile
Output
Text
Technical Specifications
Context Window
1M tokens
Max Output
128K tokens
Tokenizer
Claude
Content Moderation
Enabled
Uptime (24h)
9975.8%
Country
🇺🇸US
Release Date
September 1, 20262w
Supported Parameters
include_reasoningmax_completion_tokensmax_tokensreasoningreasoning_effortresponse_formatstopstructured_outputstoolsverbosity
Performance Over Time
Pricing
Per 1M tokens
Input$10.00
Output$50.00
Cache read$0.25
Cache write$12.50
Added
September 1, 2026
Last synced 9/16/2026