0

GLM 5 vs GPT-5.5

Head to head on 20 shared benchmarks, with price, context window, and release dates.

Benchmark scores

61

evals · sort by any column, ⤢ to expand fullscreen

Model
GPT-5.5

OpenAI

68.4%1844elo78.251.7%76.8%13.7%46.1%84.7%82.5%81.1%73.0%87.7%96.3%87.7%92.8%47.3%75.0%49.2%69.8%69.3%86.2%54.2%12.9%36.2%86.0%90.0%100.0%-1315elo34.0%51.8%-5.7%44.8%24.9%1769elo15.1%51.8%---2.1%49.1%86.9%88.6%68.8%78.7%45.3%100.0%50.0%51.5%4.2---58.6%75.7%-83.4%57.4%68.1%61.9%
GLM 5

Zai

62.9%1598elo70.916.4%66.6%7.6%55.2%71.2%73.6%67.9%55.3%77.5%83.5%69.1%65.2%38.3%70.0%39.4%23.4%97.4%-------7.9%---24.7%------97.982.7%48395-----------73.369.7%72.8%--61.12---56.4%
2 / 2 models
AttributeGLM 5

Zai

GPT-5.5

OpenAI

DescriptionGLM-5 is an AI model from Zai, released with open weights.GPT-5.5 is an AI model from OpenAI.
FamilyGlmGPT
Params--
Open weightsopenclosed
Licensemitproprietary
Released11 Feb 202623 Apr 2026
Context204,8001,050,000
Input $/1M$1.00$5.00
Output $/1M$3.20$30.00
Cache read $/1M$0.120$0.500
Cache write $/1M--
Speed0 tok/s0 tok/s
Latency0.00 s0.00 s
Modalitiestextfile, image, text
Providers--
PublisherZaiOpenAI
Reported scores

FAQ

Is GLM 5 or GPT-5.5 better?
Across the 20 benchmarks both models report on Sophon, GPT-5.5 leads on 18 of them. Which one is "better" depends on the benchmark - the table above shows every shared score.
How do GLM 5 and GPT-5.5 compare on GPQA Diamond?
GLM 5 scores 66.6% and GPT-5.5 scores 76.8% on GPQA Diamond.
Which is cheaper, GLM 5 or GPT-5.5?
GLM 5 is cheaper at $3.20 per million output tokens against $30.00 for GPT-5.5 - about 9.4x.
When were GLM 5 and GPT-5.5 released?
GLM 5 was released 11 Feb 2026 by Zai. GPT-5.5 was released 23 Apr 2026 by OpenAI.

Comparing something else? Build your own side-by-side.