Claude Fable 5.2 — Specifications
Compiled by Mustafa Ihsan from the vendor’s published documentation · Last updated
| Developer | Anthropic |
|---|---|
| Type | Reasoning / agentic |
| Modality | Text, vision |
| Parameters | Undisclosed |
| Context window | 1M |
| Max output | 128K |
| License | Proprietary |
| Open weights | No |
| Released | 2026-11 |
| Input price | $8.00 /1M |
| Output price | $40.00 /1M |
| API providers | Anthropic API, AWS, Google Cloud, Microsoft Azure |
Benchmarks
| Anthropic-reported | Terminal-Bench-Science 0.1 74.6%; FrontierCode 2.0 49.1% (xhigh effort); FrontierSWE v2 69.9%. Cache reads $0.20 per 1M tokens; fast mode $16 / $80. |
|---|
What is Claude Fable 5.2?
Claude Fable 5.2 is Anthropic’s most capable widely available model, released on 9 November 2026 together with Claude Mythos 5.2 (Anthropic’s announcement). Anthropic’s model documentation positions it for demanding reasoning and long-horizon agentic work, such as agent sessions that run for hours and research carried through to a finished document or spreadsheet. Mythos 5.2 shares its specifications and price but is offered only to organisations in Anthropic’s verification programmes.
API pricing is $8 per million input tokens and $40 per million output tokens, down from $10 and $50 for Claude Fable 5.1. Cache reads cost $0.20 per million, batch requests are 50% off, and an optional fast mode, which Anthropic says generates tokens up to 2.5 times faster, costs $16 / $80. Standard outputs are up to 30% faster than Fable 5.1. The model has a 1M-token context window, up to 128K output tokens and thinking that is always on, and runs on the Claude API as claude-fable-5-2 and on AWS, Google Cloud and Microsoft Azure.
Anthropic still recommends the cheaper Claude Opus 5.5 ($4 / $20) as the starting point for most coding and knowledge work, moving to Fable 5.2 for the hardest tasks. Launch details are in our Fable 5.2 launch story, and the AI API cost calculator compares monthly costs across the models database.
Claude Fable 5.2 pricing: API cost per 1M tokens
| Input (per 1M tokens) | $8.00 |
|---|---|
| Output (per 1M tokens) | $40.00 |
| Output/input ratio | 5× |
| Blended (4:1 in:out) | $14.40 per 1M tokens |
What Claude Fable 5.2 costs per month
Real monthly spend at a 4:1 input-to-output mix — the ratio a typical chat or RAG workload actually produces.
| Workload | Tokens / month | Cost / month |
|---|---|---|
| Side project | 1M in / 0.25M out | $18 |
| Small team | 20M in / 5M out | $360 |
| Production | 200M in / 50M out | $3,600 |
Run your own numbers in the AI API cost calculator.
Cheaper alternatives to Claude Fable 5.2
| Model | Blended $/1M | You save |
|---|---|---|
| Llama 3.1 8B open | $0.0240 | 100% cheaper |
| Mistral NeMo 12B open | $0.0292 | 100% cheaper |
| Gemma 3 4B open | $0.0600 | 100% cheaper |
Frequently asked questions
How much does Claude Fable 5.2 cost per 1M tokens?
Claude Fable 5.2 costs $8.00 per 1M input tokens and $40.00 per 1M output tokens. At a typical 4:1 input-to-output mix that blends to about $14.40 per 1M tokens.
How much does Claude Fable 5.2 cost per month?
A small-team workload of 20M input and 5M output tokens a month costs about $360 on Claude Fable 5.2. A side project (1M in / 0.25M out) costs roughly $18.00.
What is a cheaper alternative to Claude Fable 5.2?
Llama 3.1 8B is the strongest cheaper option in our database at $0.0240 per 1M blended — about 100% less than Claude Fable 5.2. It is also open-weight, so self-hosting is an option.
Can I run Claude Fable 5.2 locally?
No. Claude Fable 5.2 is a closed, API-only model — the weights are not released, so it cannot be self-hosted.
Why does Claude Fable 5.2 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 5.2 charges 5× more for output, which is why prompt-heavy workloads are far cheaper to run than generation-heavy ones.
See every Claude model priced side by side: Claude API pricing.
Prices are the published list rates for the model's primary API and are reviewed as providers change them. Volume, batch and cached-input discounts are not included. Compare every model side by side in the AI models database or the LLM leaderboard.