AnthropicTextVision

claude-fable-5.1

claude-fable-5.1 is Anthropic's model at $10.00 input and $50.00 output per million tokens, with a 1000K context window. On a typical 3:1 input-to-output mix that blends to roughly $20.00 per million tokens, placing it in the premium band of the 89 models tracked here — cheaper than 0% of them.

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MODEL OVERVIEW

Context window1000K

Input price$10 / 1M

Output price$50 / 1M

Output speed66 tok/s

Quality score97

Data updatedUpdated Sep 2026

Price verified2026-09-16 · Official

Price noteCache hits are $0.25 / 1M tokens — 0.025x base input, against the 0.1x every other Claude model uses. Batch is 50% off ($5 / $25)

By price, claude-fable-5.1 ranks 85th cheapest of 89 on input and 86th on output. Its quality score of 97 ranks 3rd of 89, and on value (quality score ÷ output price) it ranks 77th of 89. Its blended rate sits 548% above the catalog average.

In real billing terms: a support chatbot handling 50,000 turns a month (2,000 input / 500 output tokens each) costs about $2,250 per month on claude-fable-5.1, while a RAG workload of 20,000 queries (8,000 input / 800 output tokens each) runs about $2,400. Because output is priced 5.0× input here, long-generation tasks scale cost fastest — cap output length before you optimise anything else.

A 1000K context window holds roughly 1,333 pages of A4 text (at ~750 tokens per page), ranking 31st of 89 here. That is enough to drop in an entire technical manual or several source files at once, which suits long-document summarization and codebase-wide analysis. Output runs at about 66 tok/s (64th fastest of 89), acceptable interactively, though long responses will feel slow.

We track 12 Anthropic models, and claude-fable-5.1's blended rate sits 110% above that provider's average. If your task tolerates a little less headroom, GLM-5.3 (Zhipu) blends about 89% cheaper at a quality score of 94, and is worth benchmarking first. Going the other way, gpt-5.6-sol scores 98 on quality for about 60% less.

The closest model in Anthropic's line-up is claude-fable-5 ($10.00 input / $50.00 output, quality 96). Against it, claude-fable-5.1 scores 1 point higher on quality, runs 6 tok/s faster (about 10%), has a 49K smaller context window. When two models sit this close on price, the deciding factor is usually the quality ceiling — run both against your real prompts before picking.

Estimated monthly cost

Monthly API spend across four common workloads, next to the cheapest model we track.

Workload	Usage assumption	This model	Cheapest model
Support chatbot	2,000 input / 500 output tokens per turn, 50,000 turns per month	$2,250	$3.00
RAG document Q&A	8,000 input / 800 output tokens per query, 20,000 queries per month	$2,400	$3.84
Coding assistant	12,000 input / 2,000 output tokens per request, 10,000 requests per month	$2,200	$3.20
Batch summarization	4,000 input / 400 output tokens per item, 200,000 items per month	$12,000	$19

Derived directly from the rates on this page. Excludes prompt caching, batch discounts and free tiers.

How it compares

The alternatives worth benchmarking alongside it, from the same dataset.

Model	Provider	Blended /1M	Quality	Price delta
claude-fable-5.1	Anthropic	$20.00	97	—
GLM-5.3Cheaper option	Zhipu	$2.15	94	-89%
gpt-5.6-solHigher quality	OpenAI	$8.00	98	-60%
claude-fable-5Same provider	Anthropic	$20.00	96	+0%
qwen3.5Best value overall	Alibaba	$0.11	91	-99%

Best for

CodingReasoningLong Context

Modalities

TextVision

Where it fits — and where it doesn't

Good fit

Coding: writing, refactoring and debugging across multi-file project context.
Reasoning: multi-step decomposition, planning and tasks that need rigorous inference.
Long documents: a 1000K window ingests a full contract, paper or large codebase in one pass.
Multimodal input: handles images, screenshots and scanned documents directly.

Poor fit

High-frequency batch jobs: at $20.00 blended per million tokens, bills scale quickly at volume.

Frequently asked questions

How much does the claude-fable-5.1 API cost?

claude-fable-5.1 costs $10.00 per million input tokens and $50.00 per million output tokens. On a 3:1 input-to-output mix that blends to about $20.00 per million tokens.

What does claude-fable-5.1 cost per month?

It depends on volume. Using the four worked scenarios on this page: a support chatbot runs about $2,250/month, RAG document Q&A about $2,400/month, a coding assistant about $2,200/month, and batch summarization about $12,000/month. Plug your own token counts into the cost calculator for a tailored figure.

How large is the claude-fable-5.1 context window?

1000K tokens — roughly 1,333 pages of A4 text at ~750 tokens per page, ranking 31st of the 89 models tracked here.

claude-fable-5.1 or GLM-5.3 — which is better value?

GLM-5.3 blends to about $2.15 per million tokens versus $20.00 for claude-fable-5.1 — roughly 89% cheaper — at a quality score of 94 against 97. If that quality gap does not show up on your task, take the cheaper one; if it does, stay with claude-fable-5.1. Benchmark both on your own data before deciding.

What is claude-fable-5.1 best suited for?

Tagged use cases: coding, reasoning, long-context. Coding: writing, refactoring and debugging across multi-file project context. Less suitable: High-frequency batch jobs: at $20.00 blended per million tokens, bills scale quickly at volume.

How current is this claude-fable-5.1 pricing?

Pricing here was last verified on 2026-09-16 against official documentation. llmprice.app runs a daily collection job, but providers can change rates between runs — confirm against Anthropic's official pricing page before you commit.