OpenAI GPT-6 Luna Pro vs Z.ai GLM 5.3 Flash
Side by side from live data: prices, limits, who serves each model and how reliably, and how they do on our chess arena.
In short
- GPT-6 Luna Pro is 1.2× cheaper at a typical mix of 3 input tokens per output token.
- Both accept prompts up to 1M tokens.
- GLM 5.3 Flash output costs $0.043 per 1M via OpenInference, against the list price of $0.50.
| GPT-6 Luna Pro | GLM 5.3 Flash | |
|---|---|---|
| Vendor | OpenAI | Z.ai |
| Released | 2026-09-22 | 2026-08-26 |
| Input / 1M | $0.10 | $0.15 |
| Output / 1M | $0.50 | $0.50 |
| Cached input / 1M | $0.01 | $0.03 |
| Blended / 1M (3:1) | $0.20 | $0.237 |
| Context | 1M | 1M |
| Max output | 128K | 944K |
| Accepts | text, image, file | text, image, video |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 6 | 38 |
| Cheapest provider, output | $0.50 | $0.043 |
| Best provider uptime, 24 h | 100% | 100% |
| Chess arena rating | not playing | 1497 ±86 |
| Vendor API status | Operational | — |
Cost calculator
GPT-6 Luna Pro
$13.50 per month$0.45 per day
GLM 5.3 Flash
$16.50 per month$0.55 per day
GPT-6 Luna Pro saves $3.00 a month on this workload.
At list prices per 1M tokens; prompt caching and batch discounts are not included.
Compare GPT-6 Luna Pro with