Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-5.5 Pro
100
Qwen3.5-27B
65
Verified leaderboard positions: GPT-5.5 Pro unranked · Qwen3.5-27B #12
Pick GPT-5.5 Pro if you want the stronger benchmark profile. Qwen3.5-27B only becomes the better choice if knowledge is the priority or you want the cheaper token bill.
Agentic
+38.5 difference
Knowledge
+23.4 difference
GPT-5.5 Pro
Qwen3.5-27B
$30 / $180
$0 / $0
N/A
N/A
N/A
N/A
1M
262K
Pick GPT-5.5 Pro if you want the stronger benchmark profile. Qwen3.5-27B only becomes the better choice if knowledge is the priority or you want the cheaper token bill.
GPT-5.5 Pro is clearly ahead on the provisional aggregate, 100 to 65. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5 Pro's sharpest advantage is in agentic, where it averages 90.1 against 51.6. The single biggest benchmark swing on the page is BrowseComp, 90.1% to 61%. Qwen3.5-27B does hit back in knowledge, so the answer changes if that is the part of the workload you care about most.
GPT-5.5 Pro is also the more expensive model on tokens at $30.00 input / $180.00 output per 1M tokens, versus $0.00 input / $0.00 output per 1M tokens for Qwen3.5-27B. That is roughly Infinityx on output cost alone. GPT-5.5 Pro gives you the larger context window at 1M, compared with 262K for Qwen3.5-27B.
GPT-5.5 Pro is ahead on BenchLM's provisional leaderboard, 100 to 65. The biggest single separator in this matchup is BrowseComp, where the scores are 90.1% and 61%.
Qwen3.5-27B has the edge for knowledge tasks in this comparison, averaging 80.6 versus 57.2. GPT-5.5 Pro stays close enough that the answer can still flip depending on your workload.
GPT-5.5 Pro has the edge for agentic tasks in this comparison, averaging 90.1 versus 51.6. Inside this category, BrowseComp is the benchmark that creates the most daylight between them.
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