Claude Fable 5.1
The successor to Claude Fable 5, positioned above the Opus tier for demanding reasoning and long-horizon agentic work, with thinking always on and adjusted per task.
Key Specifications
- Context window
- 1M tokens
- Max output
- 128K tokens
- Knowledge cutoff
- web search available
- Released
- Inputs
- Text, image
- Capabilities Show details
- Reasoning Thinks before it answers, always on or as a switchable mode. Function calling Connect to external tools, APIs, and systems. Structured output Return responses in structured formats like JSON. Web search Search the web for up-to-date information. Code execution Write and execute code in a sandboxed environment. File upload Process uploaded documents, spreadsheets, and other files. MCP Connect to services via Model Context Protocol.
Hosted API pricing
| Provider | Input / 1M tokens | Output / 1M tokens | Cached input / 1M | Cost at 10M in + 2M out | |
|---|---|---|---|---|---|
|
Anthropic
Creator
|
$10.00 | $50.00 | $0.25 | $200.00 | View |
DigitalOcean
|
$10.00 | $50.00 | $0.25 | $200.00 | View |
Heads up: Base-tier, on-demand rates per 1M tokens; cached, batch and long-context tiers excluded. A provider may serve a shorter context or a quantized build than the creator's release. Verify before provisioning. More on how we price.
Similarly priced models
The models nearest Claude Fable 5.1 by blended rate, each at its own cheapest provider.
| Model | Blended / 1M | Input / 1M | Output / 1M | Context | Cutoff | vs Claude Fable 5.1 |
|---|---|---|---|---|---|---|
|
Claude Opus 4.7
Anthropic
|
$8.3333 | $5.00 | $25.00 | 1M | Jan 2026 | −50% |
|
Claude Opus 4.8
Anthropic
|
$8.3333 | $5.00 | $25.00 | 1M | Jan 2026 | −50% |
|
Claude Opus 5
Anthropic
|
$8.3333 | $5.00 | $25.00 | 1M | May 2026 | −50% |
GPT-5.5
OpenAI
|
$9.1667 | $5.00 | $30.00 | 1M | Dec 2025 | −45% |
|
Claude Fable 5
Anthropic
|
$16.6667 | $10.00 | $50.00 | 1M | Jan 2026 | 0% |
|
Claude Fable 5.1
This model
Anthropic
|
$16.6667 | $10.00 | $50.00 | 1M | Jun 2026 | |
|
o3-pro
OpenAI
|
$30.00 | $20.00 | $80.00 | 200K | Jun 2024 | +80% |
|
GPT-5 Pro
OpenAI
|
$32.50 | $15.00 | $120.00 | 400K | Sep 2024 | +95% |
|
GPT-5.2 Pro
OpenAI
|
$45.50 | $21.00 | $168.00 | 400K | Aug 2025 | +173% |
|
GPT-5.4 Pro
OpenAI
|
$55.00 | $30.00 | $180.00 | 1M | Aug 2025 | +230% |
|
GPT-5.5 Pro
OpenAI
|
$55.00 | $30.00 | $180.00 | 1M | Dec 2025 | +230% |
Prices are USD per 1M tokens at each model's cheapest listed provider. Blended is the cost of 10M input plus 2M output tokens, spread over the 12M.
Frequently Asked Questions
What is Claude Fable 5.1 good for?
Long-horizon agent work and hard reasoning, plus multistep research and document, spreadsheet and slide tasks. Thinking is always on and its depth is steered by an effort setting. It sits at the top of Anthropic's price range, above Opus 5.
When is Claude Fable 5.1 not a good fit?
Audio or video input, and closed weights, so no self-hosting. Cost-sensitive or high-volume work too, and Anthropic rates its latency the slowest of the current lineup and says its safety classifiers can decline requests, so plan for refusals and a fallback model.
What is the cheapest way to run Claude Fable 5.1?
The cheapest hosted rate is $10.00 / $50.00 per 1M tokens via Anthropic.
How does Claude Fable 5.1 compare with Claude Fable 5?
Anthropic says Claude Fable 5.1 extends Claude Fable 5 with stronger long-running agentic coding, multistep research, and document, spreadsheet and slide work. It adds per-message effort and readable progress updates between tool calls, and forced tool use now returns an error. Same price, 1M-token context and text and image input. Claude Fable 5.1 came out 3 months later and has a newer knowledge cutoff (June 2026 against January 2026).
Can I self-host Claude Fable 5.1?
No. Anthropic does not publish the weights; Claude Fable 5.1 is available only through hosted APIs.
More from Anthropic
| Model | Context | Input / 1M | Output / 1M |
|---|---|---|---|
|
Claude Fable 5
|
1M | $10.00 | $50.00 |
|
Claude Opus 5
|
1M | $5.00 | $25.00 |
|
Claude Opus 4.7
|
1M | $5.00 | $25.00 |
|
Claude Opus 4.8
|
1M | $5.00 | $25.00 |
|
Claude Opus 4.6
|
1M | $5.00 | $25.00 |
|
Claude Opus 4.5
|
200K | $5.00 | $25.00 |
|
Claude Sonnet 4.6
|
1M | $3.00 | $15.00 |
|
Claude Sonnet 4
|
200K | $3.00 | $15.00 |