Claude Sonnet 4.6 vs Grok 4 for Persona Consistency

Persona Consistency demands that an AI maintain an assigned character, avoid accidental persona drift, and resist prompt-injection attempts. Key capabilities: robust refusal and safety behavior (to avoid taking on illicit/contradictory persona instructions), long-context handling (to remember persona state across lengthy interactions), tool orchestration (to call functions without leaking or switching persona), and structured output when personas require specific templates. In our dataset the primary measure for this task is the internal persona_consistency score — both Claude Sonnet 4.6 and Grok 4 score 5/5, tying on the core task. Use supporting metrics to differentiate: Sonnet 4.6 scores 5 on safety_calibration and tool_calling and provides a 1,000,000-token context window and broad parameter support (structured_outputs, tool_choice, tools, include_reasoning). Grok 4 scores 2 on safety_calibration, 4 on tool_calling, offers a 256,000-token context window, and unique file-input modality; it also has a quirk of using reasoning tokens. These secondary scores explain where each model will better sustain persona in realistic workflows.

1. Long multi-session roleplay with tool calls: Sonnet 4.6 (persona_consistency 5, tool_calling 5, safety_calibration 5, context_window 1,000,000) will keep persona across extremely long histories, refuse injection attempts, and sequence tools while preserving character. 2) Upload-and-edit persona-preserving documents: Grok 4 (persona_consistency 5, modality includes file inputs, constrained_rewriting 4) is ideal when you must maintain tone/character while editing or annotating uploaded files. 3) Agentic orchestration with sensitive policy constraints: Sonnet 4.6’s 5/5 safety_calibration vs Grok 4’s 2/5 indicates Sonnet will more reliably decline harmful persona switches or illicit instructions in our tests. 4) Compact persona-preserving rewrites under tight format limits: Grok 4’s higher constrained_rewriting (4 vs Sonnet’s 3) gives it an edge when strict compression plus persona fidelity matters. 5) Cost and throughput: both models share the same input/output per-mtok rates in the payload (input 3, output 15), so pick based on context, modality, and safety/tool needs rather than raw price.

For Persona Consistency, choose Claude Sonnet 4.6 if you need extreme long-context persona maintenance, stronger safety refusals, or top-tier tool orchestration (Sonnet: persona_consistency 5, safety_calibration 5, tool_calling 5, context_window 1,000,000). Choose Grok 4 if your workflow relies on native file inputs or constrained rewriting while still keeping persona (Grok: persona_consistency 5, modality includes files, constrained_rewriting 4, context_window 256,000). Both tie on the core persona task in our tests, so pick by these secondary trade-offs.