Ask

GPT-5 Pro vs GLM-5.2

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

GPT-5 Pro Cost
$39.00
GLM-5.2 Cost
$2.28
GLM-5.2 is 94% cheaper
FeatureGPT-5 ProGLM-5.2
ProviderOpenAIZhipu AI
Input Price (1M)$15.00$1.40
Output Price (1M)$120.00$4.40
Context Window400,0001,000,000

Verdict

GPT-5 Pro costs $15.00 per 1M input tokens and $120.00 per 1M output tokens. GLM-5.2 costs $1.40 per 1M input tokens and $4.40 per 1M output tokens. GLM-5.2 is 91% cheaper on input tokens than GPT-5 Pro. For output tokens, GLM-5.2 is the more affordable option at $4.40/1M vs $120.00.

On context window, GLM-5.2 supports 1,000,000 tokens — meaning it can fit more conversation history, documents, or code in a single request. This matters for RAG pipelines, long document analysis, and agentic workflows where context builds up over many turns.

When to choose GPT-5 Pro

  • ✓ You are already integrated with OpenAI

When to choose GLM-5.2

  • ✓ You need the lowest input token cost ($ 1.40/1M)
  • ✓ Your workload is output-heavy — GLM-5.2 generates text cheaper
  • ✓ You need a larger context window (1,000,000 tokens)
  • ✓ You are already integrated with Zhipu AI

Use the calculator above to simulate your specific workload and find the exact break-even point. For most applications, the cheapest model is the one that minimises your total monthly bill given your input-to-output token ratio.

Frequently Asked Questions

Is GPT-5 Pro cheaper than GLM-5.2?

GLM-5.2 is cheaper on input tokens at $1.40/1M vs $15.00/1M for GPT-5 Pro — a 91% saving.

What is the context window of GPT-5 Pro vs GLM-5.2?

GPT-5 Pro has a 400,000-token context window. GLM-5.2 has a 1,000,000-token context window. GLM-5.2 supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: GPT-5 Pro or GLM-5.2?

The best choice depends on your use case. For cost efficiency on input tokens, GLM-5.2 is the cheaper option. For maximum context length, GLM-5.2 supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.