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AnthropicReleased on Sep 1, 2026

Claude Fable 5.1: API Pricing, Context Window & Benchmarks

Claude Fable 5.1 is a language model from Anthropic, released in September 2026, with multimodal input, a 1M-token context window, and pricing from $10.00/M input, $0.250/M cached input, $50.00/M output.

Claude Fable 5.1 is Anthropic's generally available, production-safeguarded deployment of the same underlying weights as Claude Mythos 5.1 (trusted-access only via CVP/LSVP; not cataloged here). It targets demanding reasoning and

Input
TextImage
Output
Text

Claude Fable 5.1 benchmarks

Capability tiers

Standing within each category, adjusted for leaderboard depth.

Real tasks performance

High-confidence performance for Claude Fable 5.1 across real-world prompt categories. Only 95% intervals at most 4 points wide are shown.

Performance by conversation depth

How Claude Fable 5.1 holds up as conversations get longer.

Quality Tracker

Claude Fable 5.1 Performance Across Datasets

Scores sourced from the model's scorecard, paper, or official blog posts

LLM Stats Logollm-stats.com - Tue Sep 01 2026
Notice missing or incorrect data?

Claude Fable 5.1 pricing

Providers

Claude Fable 5.1 starts at $10.00 per million input tokens and $50.00 per million output tokens via Anthropic. Reused prompt prefixes cost $0.250 per million cached input tokens.

ProviderInput $/MCached input $/MOutput $/MContext in / outTTFT p95 sOutput p5 c/sModalities in / out
Anthropic logoAnthropic
$10.00$0.250$50.001.0M/128.0K
/

Cached input is the discounted price for prompt tokens served from a provider cache. TTFT is time to first token. Output is characters per second; p5 is the sustained floor exceeded by 95% of observed requests.

Claude Fable 5.1 context window

Input and output token limits for Claude Fable 5.1, plus how it ranks on long-context understanding.

InputOutput
1Mtokens
128Ktokens
1.5k pages of text
1M
8K128K1M

Claude Fable 5.1 API

POST/v1/chat/completions

Run a request to see the response

Use it in your code

Billed at $10.00 input / $0.25 cached input / $50.00 output per 1M tokens through the LLM Stats gateway.

from openai import OpenAI

client = OpenAI(
    api_key="YOUR_API_KEY",
    base_url="https://gateway.llm-stats.com/v1"
)

response = client.chat.completions.create(
    model="claude-fable-5-1",
    messages=[
        {"role": "user", "content": "What is machine learning?"}
    ]
)

print(response.choices[0].message.content)

Need an API key? Create one above in the playground, or read the API documentation.

Claude Fable 5.1 latency

Claude Fable 5.1 time to first token, sustained output throughput, and failed-request rate from live API traffic over the trailing 7 days.

Claude Fable 5.1 examples

Recent arena outputs from Claude Fable 5.1, picked from the highest-ranked matchups.

Claude Fable 5.1 license

Claude Fable 5.1 is a proprietary model available under its provider's product and API terms.

License
Proprietary
Hosted access

Proprietary license - usage restrictions apply

Claude Fable 5.1 resources

Official sources for Claude Fable 5.1: api documentation, official playground, paper or system card, official launch post.

Claude Fable 5.1 vs other models

The most-compared alternatives to Claude Fable 5.1 are Claude Mythos Preview, Kimi K3, GLM-5.3-Flash. Open any pair side-by-side for benchmarks, pricing, context, and latency.

Models like Claude Fable 5.1

Models ranked just above and below Claude Fable 5.1 by LLM Stats score.

 

Claude Mythos Preview

Score pending
 

Kimi K3

Score pending
 

GLM-5.3-Flash

Score pending
 

GPT-5.6 Sol

Score pending
 

DeepSeek-V4-Pro-0813

Score pending
 

Gemini 3.7 Flash

Score pending

FAQ

Common questions about Claude Fable 5.1.

When was Claude Fable 5.1 released?

Claude Fable 5.1 was released on September 1, 2026 by Anthropic. This is the official Claude Fable 5.1 release date tracked on LLM Stats.

How much does Claude Fable 5.1 cost?

Claude Fable 5.1 costs $10.00 per million input tokens, $0.25 per million cached input tokens, $50.00 per million output tokens through the LLM Stats API, which works with any OpenAI-compatible SDK. Across tracked providers, the lowest price is $10.00 per million input tokens via Anthropic. That provider charges $0.25 per million cached input tokens.

Is Claude Fable 5.1 available via API?

Yes. Claude Fable 5.1 is available through the LLM Stats API and works with any OpenAI-compatible SDK — point your client at the gateway base URL and pass the model name. It is served by 1 provider tracked on LLM Stats.

Who created Claude Fable 5.1?

Claude Fable 5.1 was created by Anthropic.

What is the license for Claude Fable 5.1?

Claude Fable 5.1 is released under the Proprietary license.

Is Claude Fable 5.1 multimodal?

Yes, Claude Fable 5.1 is multimodal and can accept both text and images as input.

Where can I use Claude Fable 5.1?

Claude Fable 5.1 is available through 1 provider including Anthropic.

Where is the Claude Fable 5.1 paper or technical report?

Claude Fable 5.1 has a paper or technical report available at https://www.anthropic.com/claude-fable-5-1-mythos-5-1-system-card. Use that source for architecture, training, release and evaluation details.

What models should I compare Claude Fable 5.1 against?

Common Claude Fable 5.1 comparisons include Claude Fable 5.1 vs Claude Mythos Preview, Claude Fable 5.1 vs Kimi K3, Claude Fable 5.1 vs GLM-5.3-Flash. Compare them side by side for benchmark scores, pricing, context window, latency and API availability.