GLM 5.1 vs GPT 5.5 Pro
GLM 5.1 is cheaper on output tokens, while GPT 5.5 Pro offers a larger context window. Choose GLM 5.1 or GPT 5.5 Pro based on the trade-off between cost, context, and the benchmarks that matter for your use case.
| Spec | GLM 5.1 | GPT 5.5 Pro |
|---|---|---|
| Provider | Vercel AI Gateway | Vercel AI Gateway |
| Input / 1M tokens | $1.30 | $30.00 |
| Output / 1M tokens | $4.30 | $180.00 |
| Context window | 202K | 1M |
| Parameters | 754B | — |
| Open weights | No | No |
| Released | Apr 2026 | Apr 2026 |
FAQ
Pricing is indicative — confirm with the provider before production use. Highlighted values indicate the better figure for that row.