Claude Sonnet 5 vs Grok 4.6
Head-to-head technical comparison of intelligence, capabilities, and API pricing.
Which should you use?
Claude Sonnet 5 leads on the composite index by 1 points (94.8 vs 93.8).
Their Arena Elo differs by only 2 points, inside the confidence intervals the public board reports, so human preference does not separate them.
Pick Claude Sonnet 5 when
- Higher composite index — 94.8 against 93.8, a gap of 1 points.
- Stronger on MMLU-Pro: 94.6% against 93.1%.
Pick Grok 4.6 when
On these measures Grok 4.6 does not lead Claude Sonnet 5 anywhere, so pick it only for reasons outside this table — an existing integration, a region, or a contract.
Value per point of measured capability, at list input pricing: Claude Sonnet 5 $0.021 · Grok 4.6 $0.021 per index point. Run your own token mix through the token cost calculator — a comparison at list price ignores caching and batch discounts, which move real bills more than this gap does.
Where these numbers come from
Figures as of 2026-09-07. Arena Elo and pricing are read from the public board and each vendor's own pricing page; see the full leaderboard for all 34 models and which columns are measured rather than estimated, or the benchmark matrix for scores benchmark by benchmark.