Claude Fable 5 vs DeepSeek V4

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.	DeepSeek V4 DeepSeek's V4 generation of open-weight MoE models with 1M-token context and agent-focused reasoning modes.
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	+ MIT-licensed open weights for both Pro and Flash variants + 1M-token context window + Selectable reasoning effort modes (non-think plus two thinking modes) + Sparse MoE design keeps activated parameters low relative to total size
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	− Branded as a preview release on deepseek.com as of June 2026 − V4-Pro's scale makes self-hosting impractical without large GPU clusters
Used in stacks	0	0