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Anthropic · Claude
No. 01
Claude Fable 5
Anthropic's most capable model — the reliability frontier for the hardest agentic work.
Field notes
- Context window
- 1Mtokens
- Max output
- 128Ktokens
- Input price
- $10/ 1M tokens
- Output price
- $50/ 1M tokens
- Cached input
- $1/ 1M tokens
- Modalities
- Text, Image, Pdf
- Knowledge cutoff
- Feb 2026
- Released
- Jun 2026
- Approx. speed
- —
Overview
What this model is
Claude Fable 5 is Anthropic's most capable widely-released model and the current reliability frontier for the hardest long-horizon agentic tasks. It sustains multi-hour autonomous coding sessions without derailing, corrupting a codebase, or looping, and holds coherence across its full million-token context. It is the model practitioners reach for when a complex agentic job absolutely must complete correctly.
Strengths
- Best-in-class long-horizon agentic reliability
- Elite real-world coding and multi-file refactoring
- Sustained coherence over a 1M-token context
- Exceptional instruction following and tool use
- Strong scientific and graduate-level reasoning
Trade-offs
- Highest price in the Claude lineup
- Slower than smaller Claude models
- No audio or video input
- Output capped at 128K tokens
- Overkill for routine or high-volume workloads
Best for
- Autonomous multi-hour coding agents
- Large-scale codebase migrations and refactors
- Complex multi-step research and analysis
- High-stakes agentic workflows
- Hard reasoning and planning problems
Not ideal for
- High-volume cheap classification
- Latency-critical realtime chat
- Simple one-shot tasks where cost matters
Capabilities
Capability profile
Normalized 0–100 scores, comparable across the whole catalog.
- Reasoning
- 97
- Coding
- 98
- Math
- 94
- Writing
- 95
- Knowledge
- 94
- Speed
- 45
- Agentic
- 98
- Vision
- 89
- Multilingual
- 92
- Long Context
- 96
Benchmarks
How it scores
Public benchmark results, with independent third-party results where available. Bars normalize percentages to 100 and Elo ratings to a 1500 ceiling.
Independent index
Artificial Analysis Intelligence Index
Composite of ~9–10 independent evals · Artificial Analysis
60/ 100
BenchmarkResult
Artificial Analysis Intelligence Indexindependent
GeneralArtificial Analysis
60%
SWE-bench Verifiedindependent
CodingSWE-bench
95%
SWE-bench Proindependent
CodingSWE-bench Pro
80%
τ-benchindependent
Agenticτ-bench
89.2%
LiveBenchindependent
GeneralLiveBench
78.3%
GPQA Diamondindependent
ReasoningIndependent aggregators
94.1%
Terminal-Bench Hardindependent
AgenticArtificial Analysis
62.9%
LMArena Eloindependent
GeneralLMArena
1525Elo