Model comparison
gpt-oss-120b vs GLM-4.5-Air
- Input
- $0.039 / 1M tokens
- Output
- $0.18 / 1M tokens
- Context
- 131K
- Released
- 2025-08-05
- Input
- $0.20
- Output
- $1.10
- Context
- 128K
- Released
- 2025-07-28
Gpt-oss-120b scores higher on 3 of the 3 benchmarks both models report; gpt-oss-120b is cheaper on input tokens ($0 vs $0.2 per 1M, 5.1×); gpt-oss-120b has the larger context window (131K vs 128K).
Specs and pricing side by side
| Spec | gpt-oss-120b | GLM-4.5-Air |
|---|---|---|
| Maker | OpenAI | Z.ai (Zhipu / GLM) |
| Released | 2025-08-05 | 2025-07-28 |
| Context window | 131K | 128K |
| Max output | 131K | 96K |
| Input price | $0.039 / 1M tokens | $0.20 |
| Output price | $0.18 / 1M tokens | $1.10 |
| Parameters | 116.8B total / 5.1B active (MoE) | 106B total · 12B active |
| License | Apache 2.0 | MIT |
| Weights | Open weights | Open weightssame |
| Modalities | Text | Textsame |
| Knowledge cutoff | June 2024 | Not disclosed |
Benchmarks both models report
| Benchmark | gpt-oss-120b | GLM-4.5-Air |
|---|---|---|
| GPQA Diamond | 80.1% | 71.72% |
| AIME 2024 | 96.6% | 89.4% |
| SWE-bench Verified | 62.4% | 57.6% |
Scores are as published by each maker or its cited source; harness, reasoning effort and date can differ between rows, so treat small gaps as ties. Sources are listed on each model page.
Which one should you pick?
Pick gpt-oss-120b if…
- You care about GPQA Diamond, AIME 2024, SWE-bench Verified (it scores higher on 3 shared benchmarks).
- Cost matters: input tokens cost 5.1× less ($0 vs $0.2 per 1M).
- You need the longer context (131K vs 128K).
- Your use case is: on-premise / private reasoning assistants where data cannot leave the org.
Pick GLM-4.5-Air if…
- Your use case is: agentic coding assistants and autonomous coding agents that call tools over long horizons.
FAQ
Which is better, gpt-oss-120b or GLM-4.5-Air?
Gpt-oss-120b scores higher on 3 of the 3 benchmarks both models report; gpt-oss-120b is cheaper on input tokens ($0 vs $0.2 per 1M, 5.1×); gpt-oss-120b has the larger context window (131K vs 128K). The better pick depends on whether you value benchmark scores, price per token, context length or openness for your workload.
How much cheaper is gpt-oss-120b?
gpt-oss-120b: $0.039 / 1M tokens input, $0.18 / 1M tokens output. GLM-4.5-Air: $0.20 input, $1.10 output (list API prices as published by each maker).
What are the context windows of gpt-oss-120b and GLM-4.5-Air?
gpt-oss-120b offers 131K with up to 131K output; GLM-4.5-Air offers 128K with up to 96K output.
Is gpt-oss-120b newer than GLM-4.5-Air?
gpt-oss-120b was released 2025-08-05; GLM-4.5-Air was released 2025-07-28.