Model comparison

GPT-5.5 vs Claude Fable 5

Compare GPT-5.5 vs Claude Fable 5 API pricing: input/output token costs, cache pricing, context windows, workload estimates, and routing fit.

GPT-5.5

openai · gpt-5.5

Input
$5
Output
$30
Context
1.1M

Claude Fable 5

anthropic · claude-fable-5

Input
$10
Output
$50
Context
1M

Quick take

GPT-5.5 has the lower input price at $5 per 1M input tokens. GPT-5.5 is cheaper for the example blended workload below. GPT-5.5 has the larger context window at 1.1M tokens.

Choose GPT-5.5 if...

  • GPT-5.5 is the better default for cost-sensitive traffic and repeated high-volume calls.
  • GPT-5.5 is safer for long documents, repository analysis, and RAG prompts because it has the larger context window.

Choose Claude Fable 5 if...

  • Claude Fable 5 is a reasonable pick when its provider, latency, or integration path fits your stack better.

Example workload cost

Estimates use input tokens plus 20% output tokens. They exclude provider discounts, cache hits, and tool/search surcharges.

Workload GPT-5.5 Claude Fable 5 Cheaper
1M input + 200K output $11.00 $20.00 GPT-5.5
10M input + 2M output $110.00 $200.00 GPT-5.5
100M input + 20M output $1,100.00 $2,000.00 GPT-5.5

Context, output, and capability fit

GPT-5.5 provides the larger context window. Check max output separately when the task needs long reports, code generation, or full-document rewrites.

GPT-5.5 max output
128K
Claude Fable 5 max output
128K
GPT-5.5 features
prompt caching, function calling, vision
Claude Fable 5 features
prompt caching, function calling, vision

Risk notes for GPT-5.5

  • High output price: cap max tokens for verbose generation workloads.

Risk notes for Claude Fable 5

  • High output price: cap max tokens for verbose generation workloads.

Routing tags

frontierreasoningcodingagentslong-contextmultimodalcache-friendlyragpremiummythos-class

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