Head-to-head comparison across 1benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GPT-5.5
89
Grok Code Fast 1
42
Verified leaderboard positions: GPT-5.5 #2 · Grok Code Fast 1 unranked
Pick GPT-5.5 if you want the stronger benchmark profile. Grok Code Fast 1 only becomes the better choice if coding is the priority or you want the cheaper token bill.
Coding
+12.2 difference
GPT-5.5
Grok Code Fast 1
$5 / $30
$0.2 / $1.5
N/A
172 t/s
N/A
2.81s
1M
256K
Pick GPT-5.5 if you want the stronger benchmark profile. Grok Code Fast 1 only becomes the better choice if coding is the priority or you want the cheaper token bill.
GPT-5.5 is clearly ahead on the provisional aggregate, 89 to 42. The gap is large enough that you do not need to squint at the spreadsheet to see the difference.
GPT-5.5 is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $0.20 input / $1.50 output per 1M tokens for Grok Code Fast 1. That is roughly 20.0x on output cost alone. GPT-5.5 is the reasoning model in the pair, while Grok Code Fast 1 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 gives you the larger context window at 1M, compared with 256K for Grok Code Fast 1.
GPT-5.5 is ahead on BenchLM's provisional leaderboard, 89 to 42.
Grok Code Fast 1 has the edge for coding in this comparison, averaging 70.8 versus 58.6. GPT-5.5 stays close enough that the answer can still flip depending on your workload.
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