LIVE INTELLIGENCE · part of the Xentir AI Index

Claude Sonnet 5 vs Grok 4.5

Claude Sonnet 5 · Anthropic, released 2026-06-30
Grok 4.5 · xAI, released 2026-07-08

“Epoch AI, 'AI Benchmarking Hub'. Published online at epoch.ai. Retrieved from 'https://epoch.ai/benchmarks' [online resource].” · epoch.ai/benchmarks · Licensed CC BY 4.0 · data last verified 2026-07-26 · Methodology · Data Sources

Head-to-head

Measured on 5 of 9 tracked benchmarks for both models — Grok 4.5 leads on 5.

Benchmark	Claude Sonnet 5	Grok 4.5	Leads
Epoch Capabilities Index (ECI)	153.5	153.6	Grok 4.5
SWE-bench Verified	Not measured	Not measured	Not measured on both
GPQA Diamond	0.905 (xhigh)	0.934 (high)	Grok 4.5
MATH Level 5	Not measured	Not measured	Not measured on both
OTIS Mock AIME 2024-2025	0.947 (xhigh)	0.978 (high)	Grok 4.5
FrontierMath	Not measured	Not measured	Not measured on both
FrontierMath Tier 4	Not measured	Not measured	Not measured on both
SimpleQA Verified	0.250 (xhigh)	0.535 (high)	Grok 4.5
Chess Puzzles	0.350 (xhigh)	0.360 (high)	Grok 4.5

Benchmark results measure specific tasks and should not be treated as a universal measure of model quality. A model with no row here for a benchmark has not been measured on it — that is left blank, never estimated.

Full profiles

Claude Sonnet 5 → · Grok 4.5 → · the full AI Model Rankings table