AI model comparison

Claude Fable 5.1 vs GPT-5.6 Sol

Pricing, context window, benchmarks, and features compared side by side. Or skip the guesswork and send one prompt to both.

Claude Fable 5.1 improves on Claude Fable 5 across the board, with the biggest gains in agentic coding, long-running agentic workflows, and knowledge work: long code refactors, front-end and visual

Input / 1M
$10
Output / 1M
$50
Context
1M

GPT-5.6 Sol is the flagship model in OpenAI's GPT-5.6 series.

Input / 1M
$2
Output / 1M
$10
Context
1.05M

At a glance

Quick verdict

How the two models stack up on the things people ask about most.

Lower price

openai logo

GPT-5.6 Sol

5.0x cheaper for a typical chat

Higher intelligence score

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Claude Fable 5.1

53.4 vs 47 on Artificial Analysis

Larger context window

openai logo

GPT-5.6 Sol

1.05M vs 1M tokens

Newer release

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Claude Fable 5.1

Released September 1, 2026

Benchmarks

Benchmark scores

Independent scores from Artificial Analysis. Higher is better.

Intelligence index

anthropic logoClaude Fable 5.153.4
openai logoGPT-5.6 Sol47

Coding index

anthropic logoClaude Fable 5.181.6
openai logoGPT-5.6 Sol77.4

Agentic index

anthropic logoClaude Fable 5.157.9
openai logoGPT-5.6 Sol50.2

Pricing

Claude Fable 5.1 vs GPT-5.6 Sol API pricing

Per-token API rates. Cheaper option highlighted.

Metricanthropic logoClaude Fable 5.1openai logoGPT-5.6 Sol
Input tokensPer 1M tokens$10$2
Output tokensPer 1M tokens$50$10
Cached input (read)Per 1M tokens$0.25$0.20
Cache writePer 1M tokens$12.50$2.50
Long-context pricingPer 1M tokens, for very long promptsSame rate at any length$4 in / $15 out above 272K
Web searchPer request$0.01$0.01

What it costs in practice

Estimated cost per 1,000 requests at standard rates. Coding and long-document figures also show the cost when the input is already cached.

Chat message

2K in, 500 out

anthropic logoClaude Fable 5.1$45
openai logoGPT-5.6 Sol$9

Coding task

30K in, 4K out

anthropic logoClaude Fable 5.1$500$207.50 cached
openai logoGPT-5.6 Sol$100$46 cached

Long document summary

150K in, 2K out

anthropic logoClaude Fable 5.1$1600$137.50 cached
openai logoGPT-5.6 Sol$320$50 cached

Specs

Context window and capabilities

How much each model can read, how much it can write, and what it accepts as input.

Metricanthropic logoClaude Fable 5.1openai logoGPT-5.6 Sol
Context window1M tokens1.05M tokens
Max output128K tokens128K tokens
Input typesFile, Image, TextFile, Image, Text
Output typesTextText
Reasoning effort levelsMax, Extra high, High, Medium, LowMax, Extra high, High, Medium, Low, None
Default reasoning effortHighMedium
Release dateSeptember 1, 2026July 9, 2026

Features

Supported features

API features available for each model.

Metricanthropic logoClaude Fable 5.1openai logoGPT-5.6 Sol
Tool callingSupportedSupported
Structured outputsSupportedSupported
JSON modeSupportedSupported
ReasoningSupportedSupported
TemperatureNot supportedNot supported
Stop sequencesSupportedNot supported
Deterministic seedNot supportedSupported
Verbosity controlSupportedSupported

Our take

GPT-5.6 Sol is 5.0x cheaper for a typical chat. Claude Fable 5.1 scores higher on the Artificial Analysis Intelligence Index (53.4 vs 47). GPT-5.6 Sol has the larger context window (1.05M vs 1M tokens). The right pick depends on your workload, so the quickest way to settle it is to send the same prompt to both and compare.

FAQ

Frequently asked questions

Is Claude Fable 5.1 or GPT-5.6 Sol cheaper?

GPT-5.6 Sol is cheaper for a typical chat (2K input tokens and 500 output tokens). GPT-5.6 Sol costs $2 per 1M input tokens and $10 per 1M output tokens, while Claude Fable 5.1 costs $10 per 1M input tokens and $50 per 1M output tokens.

Which has a bigger context window, Claude Fable 5.1 or GPT-5.6 Sol?

GPT-5.6 Sol supports up to 1.05M tokens of context, compared with 1M for Claude Fable 5.1.

Is Claude Fable 5.1 smarter than GPT-5.6 Sol?

On the Artificial Analysis Intelligence Index, Claude Fable 5.1 scores 53.4 and GPT-5.6 Sol scores 47, putting Claude Fable 5.1 ahead. Benchmarks don't capture everything, so the best test is running your own prompts through both.

Can I use Claude Fable 5.1 and GPT-5.6 Sol at the same time?

Yes. Shortcut Chat sends one prompt to multiple models at once, so you can see Claude Fable 5.1 and GPT-5.6 Sol answer side by side and keep the better response.

anthropic logoopenai logo

Why choose? Ask both.

Send one prompt to Claude Fable 5.1 and GPT-5.6 Sol at the same time. Compare the answers side by side and keep the best one.