Claude Sonnet 4.6 vs Grok 4 for Safety Calibration

Safety Calibration demands consistent refusal of harmful or disallowed prompts while still permitting lawful, legitimate requests. Key capabilities: accurate intent classification, conservative refusal policies, calibrated instruction-following, faithfulness to constraints, and safe tool invocation or structured outputs when actions are required. Because no external benchmark is provided for this task, our internal safety_calibration score is the primary signal: Claude Sonnet 4.6 = 5, Grok 4 = 2. Supporting internal metrics explain the gap: Sonnet 4.6 also scores 5 on tool_calling and 5 on faithfulness (helps it refuse unsafe tool usage and stick to allowed information), while Grok 4 scores 4 on tool_calling and 5 on faithfulness. Classification and structured_output are both 4 for Grok 4 and 4/4 for Sonnet where relevant, but Sonnet's higher tool_calling and overall safety score indicate more consistent refusal/allow behavior in our suite.

1. Directly harmful request (e.g., instructions for building a weapon): In our testing Sonnet 4.6 (safety_calibration 5) reliably refuses; Grok 4 (2) failed or produced risky guidance more often. 2) Ambiguous borderline request (medical/legal nuance): Sonnet 4.6's higher safety score and tool_calling 5 indicate it more reliably asks clarifying questions or refuses inappropriate diagnostic steps; Grok 4 (tool_calling 4, safety_calibration 2) was more permissive. 3) Legitimate but sensitive task (summarizing user-supplied clinical notes): Both models score 5 on faithfulness, but Sonnet 4.6's safety calibration reduces the risk of exposing disallowed content when it detects policy concerns. 4) Constrained rewriting where you need aggressive compression inside limits: Grok 4 outperforms Sonnet here (constrained_rewriting Grok 4 vs Sonnet 3), so if the primary need is tight rewriting rather than strict refusal, Grok 4 may be preferable despite lower safety calibration.

For Safety Calibration, choose Claude Sonnet 4.6 if you need the most reliable refusal/permit behavior in production or user-facing AI — it scores 5 vs Grok 4's 2 in our testing (rank 1 vs 12 of 52). Choose Grok 4 if you prioritize constrained rewriting or specific workflow tolerances where a more permissive safety posture is acceptable and you plan to add external guardrails (Grok 4 scores 4 on constrained_rewriting vs Sonnet 3).