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GLM-5.3-Flash vs o3-mini

Detailed pricing comparison and cost analysis.

Updated September 2026

Cost Simulator

GLM-5.3-Flash Cost
$0.13
o3-mini Cost
$1.98
GLM-5.3-Flash is 94% cheaper
FeatureGLM-5.3-Flasho3-mini
ProviderZhipu AIOpenAI
Input Price (1M)$0.07$1.10
Output Price (1M)$0.25$4.40
Context Window1,000,000200,000

Verdict

GLM-5.3-Flash costs $0.07 per 1M input tokens and $0.25 per 1M output tokens. o3-mini costs $1.10 per 1M input tokens and $4.40 per 1M output tokens. GLM-5.3-Flash is 93% cheaper on input tokens than o3-mini. For output tokens, GLM-5.3-Flash is the more affordable option at $0.25/1M vs $4.40.

On context window, GLM-5.3-Flash 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 GLM-5.3-Flash

  • ✓ You need the lowest input token cost ($ 0.07/1M)
  • ✓ Your workload is output-heavy — GLM-5.3-Flash generates text cheaper
  • ✓ You need a larger context window (1,000,000 tokens)
  • ✓ You are already integrated with Zhipu AI

When to choose o3-mini

  • ✓ You are already integrated with OpenAI

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 GLM-5.3-Flash cheaper than o3-mini?

GLM-5.3-Flash is cheaper on input tokens at $0.07/1M vs $1.10/1M for o3-mini — a 93% saving.

What is the context window of GLM-5.3-Flash vs o3-mini?

GLM-5.3-Flash has a 1,000,000-token context window. o3-mini has a 200,000-token context window. GLM-5.3-Flash supports the larger context, suitable for longer documents and agentic workflows.

Which model is better: GLM-5.3-Flash or o3-mini?

The best choice depends on your use case. For cost efficiency on input tokens, GLM-5.3-Flash is the cheaper option. For maximum context length, GLM-5.3-Flash supports 1,000,000 tokens. Use the comparison table above to find the right fit for your workload.