gpt-oss-120b is an open-weight, 117B-parameter Mixture-of-Experts (MoE) language model from OpenAI designed for high-reasoning, agentic, and general-purpose production use cases. It activates 5.1B parameters per forward pass and is optimize…
Model details →OpenAI: gpt-oss-120b (free) vs Z.ai: GLM 5.2 (free)
OpenAI: gpt-oss-120b (free) wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
GLM 5.2 is a large-scale reasoning model from Z.ai. It supports text input and output with a 1M-token context window, and is suited for long-horizon agent workflows, project-level software engineering,...
Model details →Side-by-side comparison
| Capability | OpenAI: gpt-oss-120b (free) | Z.ai: GLM 5.2 (free) | Winner |
|---|---|---|---|
| Context window Maximum number of input tokens the model can attend to in a single request. | 131K | 128K | 🏆 OpenAI: gpt-oss-120b (free) |
| Input price (per 1M) Cost per million input tokens billed by the provider. | $0.00 | $0.00 | Tie |
| Output price (per 1M) Cost per million output tokens billed by the provider. | $0.00 | $0.00 | Tie |
| Tool / function calling First-class support for emitting structured tool calls. | Yes | — | 🏆 OpenAI: gpt-oss-120b (free) |
| Vision input Accepts image inputs alongside text. | — | — | Tie |
| Reasoning mode Internal chain-of-thought / extended-thinking support. | Yes | Yes | Tie |
Frequently asked questions
Is OpenAI: gpt-oss-120b (free) better than Z.ai: GLM 5.2 (free)?
OpenAI: gpt-oss-120b (free) wins on 2 of 6 axes — pricing and capability skew in its favour for most workloads.
What's the price difference between OpenAI: gpt-oss-120b (free) and Z.ai: GLM 5.2 (free)?
Input: $0.00 vs $0.00 per 1M tokens. Output: $0.00 vs $0.00 per 1M tokens.
What context windows do OpenAI: gpt-oss-120b (free) and Z.ai: GLM 5.2 (free) support?
OpenAI: gpt-oss-120b (free) supports up to 131K tokens. Z.ai: GLM 5.2 (free) supports up to 128K tokens.
Do both OpenAI: gpt-oss-120b (free) and Z.ai: GLM 5.2 (free) support tool calling?
OpenAI: gpt-oss-120b (free): yes. Z.ai: GLM 5.2 (free): not advertised.