Claude Sonnet 4.6 vs Grok 3

Summary of our 12-test comparison (scores from our internal suite, plus external Epoch AI tests where available):

• Wins for Claude Sonnet 4.6 (in our testing): creative_problem_solving 5 vs 3 (Sonnet ranks tied for 1st of 54), tool_calling 5 vs 4 (Sonnet tied for 1st of 54 with 16 others) and safety_calibration 5 vs 2 (Sonnet tied for 1st of 55; Grok ranks 12 of 55). Those differences mean Sonnet is markedly better at generating non-obvious feasible ideas, selecting and sequencing functions with correct arguments, and refusing/allowing requests appropriately in safety-sensitive contexts.
• Win for Grok 3: structured_output 5 vs 4. Grok’s 5 in structured_output (tied for 1st of 54) indicates superior JSON/schema compliance and format adherence in our tests — useful when downstream parsers fail on malformed output.
• Ties (both models match in our testing): strategic_analysis (5/5), constrained_rewriting (3/3), faithfulness (5/5), classification (4/4), long_context (5/5), persona_consistency (5/5), agentic_planning (5/5) and multilingual (5/5). Practically, both models are equivalent for long-context retrieval (30K+ tokens), maintaining persona, classification, and goal decomposition.
• External benchmarks (Epoch AI): Claude Sonnet 4.6 scores 75.2% on SWE-bench Verified and 85.8% on AIME 2025 (Epoch AI); Grok 3 has no external scores in the payload. The SWE-bench 75.2% places Sonnet 4th of 12 on that external coding measure in our records, which supports the internal finding that Sonnet is strong on coding/tooling tasks. Overall: Sonnet’s clear advantages are tool calling and safety; Grok’s clear advantage is structured output. Many other dimensions are tied.

Both models use identical pricing in the payload: $3 per 1K input tokens and $15 per 1K output tokens. At scale that matters: 1M tokens = 1,000 mTok → $3,000 input or $15,000 output; split 50/50 input/output costs ~$9,000/month. At 10M tokens (10,000 mTok) it's $30,000 input or $150,000 output; 50/50 ≈ $90,000/month. At 100M tokens it's $300,000 input or $1,500,000 output; 50/50 ≈ $900,000/month. Because pricing is identical, choose on capability: teams doing heavy tool calling, safety-sensitive automation, or complex codebase work should prioritize Claude Sonnet 4.6; teams that require stricter schema/JSON compliance at high volume should consider Grok 3 but won’t gain a cost advantage.

Choose Claude Sonnet 4.6 if: you need best-in-class tool calling, safety-sensitive responses, creative problem solving, or strong coding performance (Claude wins tool_calling and safety_calibration and posts 75.2% on SWE-bench Verified, Epoch AI). Ideal for agentic workflows, complex tool chains, and production systems that require robust refusal behavior.
Choose Grok 3 if: your top requirement is exact JSON/schema compliance and structured outputs (structured_output 5 vs 4) or you prefer its text->text modality; Grok matches Sonnet on long-context, classification, multilingual, faithfulness, and agentic planning, so it’s a solid choice where schema adherence is the gating constraint.
Because both models have identical pricing ($3/1K in, $15/1K out), pick on capability and safety needs rather than cost.