Head-to-head comparison across 4benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
Claude Sonnet 4.5
68
GPT-5.2
83
Pick GPT-5.2 if you want the stronger benchmark profile. Claude Sonnet 4.5 only becomes the better choice if coding is the priority or you would rather avoid the extra latency and token burn of a reasoning model.
Agentic
+0.1 difference
Coding
+12.5 difference
Reasoning
+39.3 difference
Knowledge
+9.0 difference
Claude Sonnet 4.5
GPT-5.2
$3 / $15
$2 / $8
N/A
73 t/s
N/A
130.34s
200K
400K
Pick GPT-5.2 if you want the stronger benchmark profile. Claude Sonnet 4.5 only becomes the better choice if coding is the priority or you would rather avoid the extra latency and token burn of a reasoning model.
GPT-5.2 is clearly ahead on the provisional aggregate, 83 to 68. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.2's sharpest advantage is in reasoning, where it averages 52.9 against 13.6. The single biggest benchmark swing on the page is ARC-AGI-2, 13.6% to 52.9%. Claude Sonnet 4.5 does hit back in coding, so the answer changes if that is the part of the workload you care about most.
Claude Sonnet 4.5 is also the more expensive model on tokens at $3.00 input / $15.00 output per 1M tokens, versus $2.00 input / $8.00 output per 1M tokens for GPT-5.2. GPT-5.2 is the reasoning model in the pair, while Claude Sonnet 4.5 is not. That usually helps on harder chain-of-thought-heavy tests, but it can also mean more latency and more token spend in real use. GPT-5.2 gives you the larger context window at 400K, compared with 200K for Claude Sonnet 4.5.
GPT-5.2 is ahead on BenchLM's provisional leaderboard, 83 to 68. The biggest single separator in this matchup is ARC-AGI-2, where the scores are 13.6% and 52.9%.
GPT-5.2 has the edge for knowledge tasks in this comparison, averaging 92.4 versus 83.4. Inside this category, GPQA is the benchmark that creates the most daylight between them.
Claude Sonnet 4.5 has the edge for coding in this comparison, averaging 77.2 versus 64.7. Inside this category, SWE-bench Verified is the benchmark that creates the most daylight between them.
GPT-5.2 has the edge for reasoning in this comparison, averaging 52.9 versus 13.6. Inside this category, ARC-AGI-2 is the benchmark that creates the most daylight between them.
Claude Sonnet 4.5 has the edge for agentic tasks in this comparison, averaging 55.3 versus 55.2. Inside this category, OSWorld-Verified is the benchmark that creates the most daylight between them.
For engineers, researchers, and the plain curious — a weekly brief on new models, ranking shifts, and pricing changes.
Free. No spam. Unsubscribe anytime.