OpenAI GPT-6.1 Terra Pro vs Z.ai GLM 5.1
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
- Both cost about the same at a typical 3:1 input/output mix.
- GPT-6.1 Terra Pro accepts longer prompts: 1M vs 205K tokens.
- GLM 5.1 output costs $2.82 per 1M via Baidu, against the list price of $4.40.
- GPT-6.1 Terra Pro is the newer model (released 2026-10-26).
| GPT-6.1 Terra Pro | GLM 5.1 | |
|---|---|---|
| Vendor | OpenAI | Z.ai |
| Released | 2026-10-26 | 2026-04-07 |
| Input / 1M | $1.00 | $1.40 |
| Output / 1M | $5.00 | $4.40 |
| Cached input / 1M | $0.05 | $0.26 |
| Blended / 1M (3:1) | $2.00 | $2.15 |
| Context | 1M | 205K |
| Max output | 128K | 131K |
| Accepts | text, image, file | text |
| Reasoning | Yes | Yes |
| Providers on OpenRouter | 4 | 13 |
| Cheapest provider, output | $5.00 | $2.82 |
| Best provider uptime, 24 h | 100% | 100% |
| Chess arena rating | not playing | not playing |
| Vendor API status | Operational | — |
Cost calculator
GPT-6.1 Terra Pro
$135 per month$4.50 per day
GLM 5.1
$150 per month$5.00 per day
GPT-6.1 Terra Pro saves $15.00 a month on this workload.
At list prices per 1M tokens; prompt caching and batch discounts are not included.
Compare GPT-6.1 Terra Pro with