GLM-5.1 vs GPT-5.2 Codex
GLM-5.1 (2026) and GPT-5.2 Codex (2025) are agentic coding models from Zhipu AI and OpenAI. GLM-5.1 ships a 200k-token context window, while GPT-5.2 Codex ships a not-yet-sourced context window. This comparison covers specs, pricing, capabilities, benchmarks, provider availability, and production fit. It focuses on practical selection signals rather than broad model-family marketing. The goal is to make the tradeoff clear before deeper testing.
GLM-5.1 is safer overall; choose GPT-5.2 Codex when coding workflow support matters.
Specs
| Released | 2026-03-27 | 2025-12-18 |
| Context window | 200k | — |
| Parameters | 744B total, 40-44B active | — |
| Architecture | mixture of experts | decoder only |
| License | Proprietary | Proprietary |
| Knowledge cutoff | - | - |
Pricing and availability
| GLM-5.1 | GPT-5.2 Codex | |
|---|---|---|
| Input price | $0.95/1M tokens | - |
| Output price | $3.15/1M tokens | - |
| Providers | - |
Capabilities
| GLM-5.1 | GPT-5.2 Codex | |
|---|---|---|
| Vision | ||
| Multimodal | ||
| Reasoning | ||
| Function calling | ||
| Tool use | ||
| Structured outputs | ||
| Code execution |
Benchmarks
No shared benchmark rows are currently sourced for this pair.
Deep dive
The capability footprint differs most on vision: GPT-5.2 Codex, multimodal input: GPT-5.2 Codex, and structured outputs: GLM-5.1. Both models share reasoning mode, function calling, tool use, and code execution, so the practical split is not just feature count. Use those differences to decide whether the page is about raw model quality, agentic coding support, multimodal ingestion, or predictable structured API behavior.
Pricing coverage is uneven: GLM-5.1 has $0.95/1M input tokens and GPT-5.2 Codex has no token price sourced yet. Provider availability is 2 tracked routes versus 0. Treat unknown pricing as an integration gap, then verify the route you will actually call before estimating production spend.
Choose GLM-5.1 when coding workflow support and broader provider choice are central to the workload. Choose GPT-5.2 Codex when coding workflow support are more important. For production, rerun your own prompts through the exact provider, region, and tool stack you plan to ship. This keeps the decision grounded in measurable tradeoffs instead of brand-level assumptions. It also helps separate model capability from provider packaging, which can change cost and latency. For teams standardizing a stack, that distinction is often the difference between a benchmark win and a reliable deployment.
FAQ
Is GLM-5.1 or GPT-5.2 Codex open source?
GLM-5.1 is listed under Proprietary. GPT-5.2 Codex is listed under Proprietary. License labels affect whether you can self-host, redistribute weights, or rely only on hosted APIs, so confirm the upstream license before deployment.
Which is better for vision, GLM-5.1 or GPT-5.2 Codex?
GPT-5.2 Codex has the clearer documented vision signal in this comparison. If vision is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for multimodal input, GLM-5.1 or GPT-5.2 Codex?
GPT-5.2 Codex has the clearer documented multimodal input signal in this comparison. If multimodal input is mission-critical, validate it against the provider endpoint because model-level support and API-level exposure can differ.
Which is better for reasoning mode, GLM-5.1 or GPT-5.2 Codex?
Both GLM-5.1 and GPT-5.2 Codex expose reasoning mode. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Which is better for function calling, GLM-5.1 or GPT-5.2 Codex?
Both GLM-5.1 and GPT-5.2 Codex expose function calling. The better choice depends on benchmark fit, context budget, pricing, and whether your provider route exposes the same capability surface. Use this as a quick comparison signal, then confirm the provider-specific limits before committing to production.
Where can I run GLM-5.1 and GPT-5.2 Codex?
GLM-5.1 is available on Z.ai and OpenRouter. GPT-5.2 Codex is available on the tracked providers still being sourced. Provider coverage can affect latency, region availability, compliance posture, and fallback options.
Continue comparing
Last reviewed: 2026-04-24. Data sourced from public model cards and provider documentation.