Claude Sonnet 4.6 vs GPT-5.3 Codex — Who Actually Wins? Real Benchmark Data (2026)

head to head

Claude Sonnet 4.6 vs GPT-5.3 Codex

4 shared benchmarks

1

wins

0

ties

3

wins

89.9%

GPQA Diamond

91.5%

72.5%

OSWorld

64.0%

79.6%

SWE-bench Verified

80.0%

59.1%

Terminal-Bench 2.0

77.3%