Head-to-head comparison across 2benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
DeepSeek V4 Flash Base
31
GPT-5.5
93
Verified leaderboard positions: DeepSeek V4 Flash Base unranked · GPT-5.5 #3
Pick GPT-5.5 if you want the stronger benchmark profile. DeepSeek V4 Flash Base only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.
Reasoning
+40.3 difference
Knowledge
+14.2 difference
DeepSeek V4 Flash Base
GPT-5.5
$null / $null
$5 / $30
N/A
N/A
N/A
N/A
1M
1M
Pick GPT-5.5 if you want the stronger benchmark profile. DeepSeek V4 Flash Base only becomes the better choice if you would rather avoid the extra latency and token burn of a reasoning model.
GPT-5.5 is clearly ahead on the provisional aggregate, 93 to 31. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5's sharpest advantage is in reasoning, where it averages 85 against 44.7.
GPT-5.5 is the reasoning model in the pair, while DeepSeek V4 Flash Base 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-5.5 is ahead on BenchLM's provisional leaderboard, 93 to 31.
GPT-5.5 has the edge for knowledge tasks in this comparison, averaging 66.4 versus 52.2. DeepSeek V4 Flash Base stays close enough that the answer can still flip depending on your workload.
GPT-5.5 has the edge for reasoning in this comparison, averaging 85 versus 44.7. DeepSeek V4 Flash Base stays close enough that the answer can still flip depending on your workload.
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