GPT-5 nano vs GLM-5.3: cost

For a typical support chatbot, GPT-5 nano is about 14.0× cheaper than GLM-5.3 ($28.14 vs $393 per month). Price is only one factor: test both on your own prompts before switching.

GPT-5 nano vs GLM-5.3: prices and limits
GPT-5 nanoGLM-5.3
Input /1M$0.05$1.40
Output /1M$0.40$4.40
Cached input /1M$0.005$0.26
Batch input /1M$0.025—
Batch output /1M$0.20—
Context window400,0001,000,000
Max input272,0001,000,000
Max output128,000128,000

Monthly cost by workload

Estimated monthly cost by workload (USD)
Scenario (per month)GPT-5 nanoGLM-5.3
Customer support chatbot
5,000 req/day · 1,200 in · 400 out · cache 60%
$28.14$393
RAG over documents
2,000 req/day · 8,000 in · 600 out · cache 30%
$31.92$666
Coding agent
1,500 req/day · 25,000 in · 2,000 out · cache 80%
$51.75$945
Deep reasoning
800 req/day · 3,000 in · 6,000 out · cache 20%
$60.55$718
Batch processing
50,000 req/day · 1,500 in · 150 out · batch
$101$4,140