Claude Sonnet 4.6 vs Grok Code Fast 1

Summary of our 12-test comparison (scores are from our testing):

• Wins for Claude Sonnet 4.6 (in our testing): strategic_analysis 5 vs 3 (Sonnet ranks tied 1st of 54; Grok ranks 36/54). Creative_problem_solving 5 vs 3 (Sonnet tied 1st of 54; Grok rank 30/54). Tool_calling 5 vs 4 (Sonnet tied for 1st of 54 with 16 others; Grok rank 18/54). Faithfulness 5 vs 4 (Sonnet tied for 1st of 55; Grok rank 34/55). Long_context 5 vs 4 (Sonnet tied for 1st of 55; Grok rank 38/55). Safety_calibration 5 vs 2 (Sonnet tied for 1st of 55; Grok rank 12/55). Persona_consistency 5 vs 4 (Sonnet tied for 1st of 53; Grok rank 38/53). Multilingual 5 vs 4 (Sonnet tied for 1st of 55; Grok rank 36/55).
• Ties (both models): structured_output 4/4 (both rank ~26/54), constrained_rewriting 3/3 (both rank 31/53), classification 4/4 (both tied for 1st of 53), agentic_planning 5/5 (both tied for 1st of 54). Interpretation for real tasks: Sonnet’s advantages matter when you need safe refusals and high faithfulness (reduces hallucination risk in customer-facing flows), robust tool calling and long-context handling (large codebases, multi-file agent workflows), and stronger multilingual and creative problem solving. Grok matches Sonnet on classification and agentic planning, and ties on structured output and constrained rewriting, so for routing/tagging, decomposing goals, or strict output formats Grok is sufficient. No benchmark in our 12-test suite shows Grok strictly outperforming Sonnet. External benchmarks: beyond our internal suite, Sonnet scores 75.2% on SWE-bench Verified and ranks 4 of 12 (Epoch AI), and 85.8% on AIME 2025, rank 10 of 23 (Epoch AI) — these external results support Sonnet’s coding and math strengths relative to other models on those third-party tests.

Prices from the payload: Claude Sonnet 4.6 input $3/mTok and output $15/mTok; Grok Code Fast 1 input $0.2/mTok and output $1.5/mTok (mTok = 1,000 tokens). Using a 50/50 input/output split as an example: per 1M tokens (500k input + 500k output) Sonnet costs $9,000 (3500 + 15500 = $1,500 + $7,500), Grok costs $850 (0.2500 + 1.5500 = $100 + $750). At 10M tokens those totals scale to $90,000 vs $8,500; at 100M tokens, $900,000 vs $85,000. Who should care: enterprise projects with large-volume inference or chatbots will feel Sonnet’s cost quickly and should budget accordingly; small teams, prototypes, or high-throughput services that need cost-efficient inference should prefer Grok for its ~10× lower per-token bill.

Choose Claude Sonnet 4.6 if you need top-tier safety, faithfulness, tool calling, and long-context performance for professional coding, end-to-end agent workflows, or multilingual customer-facing apps and you can absorb higher inference costs. Choose Grok Code Fast 1 if you need a much lower per-token price, faster/economic experimentation, visible reasoning tokens for developer steering, or high-throughput non-production services where the ~10× cost gap matters.