GPT-5.3 Codex vs Gemini 3 Flash — Who Actually Wins? Real Benchmark Data (2026)

head to head

GPT-5.3 Codex vs Gemini 3 Flash

2 shared benchmarks

2

wins

0

ties

0

wins

91.5%

GPQA Diamond

90.4%

80.0%

SWE-bench Verified

78.0%