Claude Fable 5 vs Qwen3.5 (397B-A17B)

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.	Qwen3.5 (397B-A17B) Alibaba's Apache-2.0 open-weight Qwen3.5 flagship MoE with very low active-parameter cost and broad multilingual coverage.
Category	model	model
Vendor type	commercial	open source
Pricing	usage	free
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	+ Permissive Apache 2.0 license + Only 17B active parameters, enabling comparatively cheap inference + First-class MCP and tool-calling support via Qwen-Agent + 201-language coverage for multilingual agents
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	− Long context beyond 262K requires YaRN extension rather than native support − Flagship commercial Qwen3-Max capabilities are not part of the open release
Used in stacks	0	0