Claude Fable 5 vs GPT-5.5

Pick two tools from the same category to compare side-by-side.

	Claude Fable 5 Anthropic's most capable widely released model, built for demanding reasoning and long-horizon agentic work.	GPT-5.5 OpenAI's flagship frontier model, positioned as a new class of intelligence for coding and professional work.
Category	model	model
Vendor type	commercial	commercial
Pricing	usage	usage
Strengths	+ Vendor-stated state-of-the-art on nearly all tested benchmarks, with the lead growing on longer, more complex tasks + 1M-token context window and up to 128k output tokens per request + Built for long-horizon autonomous agent work with memory tool, compaction, and programmatic tool calling + Server-side fallback parameter and fallback credit simplify refusal handling	+ OpenAI's recommended model for complex reasoning and coding + 1M-token context window with up to 128K output tokens + Generally available via the OpenAI API with listed pricing of $5 input / $30 output per million tokens
Tradeoffs	− Premium pricing: $10 per million input tokens and $50 per million output tokens − Safety classifiers can refuse requests (vendor says under 5% of sessions on average, sometimes catching harmless ones), so integrations must handle stop_reason refusal − 30-day data retention required; not available under zero data retention	− Most expensive tier in OpenAI's lineup; GPT-5.4 is positioned as the more affordable option for similar work − API-only commercial model; no open weights
Used in stacks	0	0