Claude Opus 4.6 vs Grok 4.1 Fast

Across our 12-test suite: Claude Opus 4.6 wins 4 tests, Grok 4.1 Fast wins 3, and they tie on 5. Detailed breakdown (scores are from our 1–5 scale):

• Opus wins: creative_problem_solving 5 vs 4 (Opus tied for 1st of 54), tool_calling 5 vs 4 (Opus tied for 1st of 54; Grok ranks 18/54), agentic_planning 5 vs 4 (Opus tied for 1st of 54; Grok rank 16/54), safety_calibration 5 vs 1 (Opus tied for 1st; Grok ranks 32/55). High safety_calibration (5) means Opus refused/handled harmful prompts more correctly in our tests. Tool_calling 5 indicates better function selection and sequencing in our scenarios.
• Grok wins: structured_output 5 vs 4 (Grok tied for 1st of 54; Opus rank 26/54), constrained_rewriting 4 vs 3 (Grok rank 6/53; Opus rank 31/53), classification 4 vs 3 (Grok tied for 1st of 53; Opus rank 31/53). That translates to stronger JSON/schema compliance, tighter compression into hard limits, and more reliable routing/class labels in our evaluations.
• Ties (both score 5): strategic_analysis, faithfulness, long_context, persona_consistency, multilingual — both models are top-tier here (Opus and Grok share top ranks on strategic analysis and long context; both tie for 1st on faithfulness and persona). Specifically, Opus scores 78.7% on SWE-bench Verified (Epoch AI) and 94.4% on AIME 2025 in our data — the SWE-bench result is a supplementary third-party datapoint (Epoch AI) showing Opus's strength on code/issue resolution tasks. In short: Opus dominates safety and agentic/tool workflows; Grok leads on structured outputs, constrained rewriting, and classification; for many general reasoning and long-context tasks they perform similarly.

Price per 1k tokens (mTok): Claude Opus 4.6 charges $5 input / $25 output; Grok 4.1 Fast charges $0.20 input / $0.50 output (price ratio 50x). At 1M tokens (1,000 mTok) with a 50/50 input/output split: Opus ≈ $15,000 (500 mTok input = $2,500; 500 mTok output = $12,500) vs Grok ≈ $350 (500 mTok input = $100; 500 mTok output = $250). At 10M tokens: Opus ≈ $150,000 vs Grok ≈ $3,500. At 100M tokens: Opus ≈ $1,500,000 vs Grok ≈ $35,000. High-volume apps (customer support, large-scale retrieval, SaaS with millions of monthly tokens) will see substantial savings with Grok; teams that need Opus's higher-scoring safety, tool-calling, and agentic planning should budget for an order-of-magnitude higher spend.

Choose Claude Opus 4.6 if you need: agentic planning, reliable tool calling, strict safety calibration, or top coding/long-workflow performance (Opus: tool_calling 5/5, safety_calibration 5/5, SWE-bench Verified 78.7% (Epoch AI)). Choose Grok 4.1 Fast if you need: the lowest cost at scale and best-in-class structured output and classification (Grok: structured_output 5/5, classification 4/5) — ideal for high-volume customer support or structured pipelines where token costs dominate. If budget allows and safety/tool orchestration matter, pay for Opus; if token spend is the limiting factor, Grok delivers similar long-context and persona results at far lower cost.