Claude Fable 5.1 vs GPT-5.6 Sol

Side-by-side pricing per provider, context window, benchmark scores and speed, all on one OpenAI-compatible API.

Metric
Claude Fable 5.1Anthropicanthropic/claude-fable-5.1
GPT-5.6 SolOpenAIopenai/gpt-5.6-sol
Creator
Anthropic
OpenAI
Released
Sep 1, 2026
Jul 9, 2026
Context window
1M
1.05M (best)
Max output
128K
128K
Input / 1MLowest provider price
$10.00
$4.00 (best)
Output / 1MLowest provider price
$50.00
$20.00 (best)
Providers
1
1
IntelligenceArtificial Analysis index
51.2 (best)
42.3
CodingArtificial Analysis index
79.1 (best)
77.2
LatencyMedian time to first token
—
5.7s
ThroughputMedian tokens per second
—
<1 t/s
Accepts
Text, Image, Files
Text, Image
Produces
Text
Text
Tool calling
Yes
Yes
Structured output
Yes
Yes
Reasoning
Yes
Yes

Claude Fable 5.1 vs GPT-5.6 Sol: summary

Claude Fable 5.1 and GPT-5.6 Sol are both available through FastRouter's OpenAI-compatible API, so switching between them is a change of model id, not a new integration.

Claude Fable 5.1, from Anthropic, has a 1,000,000-token context window, costs $10.00/1M input and $50.00/1M output tokens and scores 51.2 on the Artificial Analysis Intelligence Index.

GPT-5.6 Sol, from OpenAI, has a 1,050,000-token context window, costs $4.00/1M input and $20.00/1M output tokens and scores 42.3 on the Artificial Analysis Intelligence Index.

GPT-5.6 Sol is the cheapest on input, 2.5× cheaper than the next model, GPT-5.6 Sol has the largest context window, Claude Fable 5.1 scores highest for intelligence and Claude Fable 5.1 leads on coding.

Switch with one line

client = OpenAI(base_url="https://api.fastrouter.ai/api/v1", api_key="<FASTROUTER_API_KEY>") client.chat.completions.create(model="anthropic/claude-fable-5.1", messages=[...]) # or client.chat.completions.create(model="openai/gpt-5.6-sol", messages=[...])
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Benchmark scores sourced from ArtificialAnalysis