Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Sonnet 5
94
GPT-5.3 Codex
85
Pick Claude Sonnet 5 if you want the stronger benchmark profile. GPT-5.3 Codex only becomes the better choice if you want the cheaper token bill.
Agentic
+10.3 difference
Coding
+0.1 difference
Claude Sonnet 5
GPT-5.3 Codex
$3 / $15
$1.75 / $14
N/A
79 t/s
N/A
88.26s
1M
400K
Pick Claude Sonnet 5 if you want the stronger benchmark profile. GPT-5.3 Codex only becomes the better choice if you want the cheaper token bill.
Claude Sonnet 5 is clearly ahead on the provisional aggregate, 94 to 85. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
Claude Sonnet 5's sharpest advantage is in agentic, where it averages 81.8 against 71.5. The single biggest benchmark swing on the page is OSWorld-Verified, 81.2% to 64.7%.
Claude Sonnet 5 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $1.75 input / $14.00 output per 1M tokens for GPT-5.3 Codex. Claude Sonnet 5 gives you the larger context window at 1M, compared with 400K for GPT-5.3 Codex.
Claude Sonnet 5 is ahead on BenchLM's provisional leaderboard, 94 to 85. The biggest single separator in this matchup is OSWorld-Verified, where the scores are 81.2% and 64.7%.
Claude Sonnet 5 has the edge for coding in this comparison, averaging 63.2 versus 63.1. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.
Claude Sonnet 5 has the edge for agentic tasks in this comparison, averaging 81.8 versus 71.5. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.
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