Head-to-head comparison across 4benchmark categories. Overall scores shown here use BenchLM's provisional ranking lane.
GLM-5
67
GPT-5.5
89
Verified leaderboard positions: GLM-5 #14 · GPT-5.5 #2
Pick GPT-5.5 if you want the stronger benchmark profile. GLM-5 only becomes the better choice if coding is the priority or you want the cheaper token bill.
Agentic
+25.6 difference
Coding
+4.6 difference
Reasoning
+24.2 difference
Knowledge
+4.3 difference
GLM-5
GPT-5.5
$1 / $3.2
$5 / $30
74 t/s
N/A
1.64s
N/A
200K
1M
Pick GPT-5.5 if you want the stronger benchmark profile. GLM-5 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 67. 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 agentic, where it averages 81.8 against 56.2. The single biggest benchmark swing on the page is Terminal-Bench 2.0, 56.2% to 82.7%. GLM-5 does hit back in coding, so the answer changes if that is the part of the workload you care about most.
GPT-5.5 is also the more expensive model on tokens at $5.00 input / $30.00 output per 1M tokens, versus $1.00 input / $3.20 output per 1M tokens for GLM-5. That is roughly 9.4x on output cost alone. GPT-5.5 is the reasoning model in the pair, while GLM-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-5.5 gives you the larger context window at 1M, compared with 200K for GLM-5.
GPT-5.5 is ahead on BenchLM's provisional leaderboard, 89 to 67. The biggest single separator in this matchup is Terminal-Bench 2.0, where the scores are 56.2% and 82.7%.
GLM-5 has the edge for knowledge tasks in this comparison, averaging 70.7 versus 66.4. Inside this category, GPQA is the benchmark that creates the most daylight between them.
GLM-5 has the edge for coding in this comparison, averaging 63.2 versus 58.6. Inside this category, SWE-bench Pro is the benchmark that creates the most daylight between them.
GPT-5.5 has the edge for reasoning in this comparison, averaging 85 versus 60.8. GLM-5 stays close enough that the answer can still flip depending on your workload.
GPT-5.5 has the edge for agentic tasks in this comparison, averaging 81.8 versus 56.2. Inside this category, MCP Atlas is the benchmark that creates the most daylight between them.
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