GPT-5.6 Terra vs Sonar Pro
Side-by-side specs, pricing and capabilities. Both models run on Clade under one subscription, so you can switch between them in the same conversation.
GPT-5.6 Terra comes from OpenAI and Sonar Pro from Perplexity. The practical difference for most people is context, price, and which input types each one accepts.
GPT-5.6 Terra holds more in a single conversation — 1.1M tokens against 128K — which matters for long documents and large codebases.
GPT-5.6 Terra is the cheaper of the two on input tokens at $2.00 / 1M tokens.
| Specification | GPT-5.6 Terra | Sonar Pro |
|---|---|---|
| Provider | OpenAI | Perplexity |
| Model ID | gpt-5.6-terra | sonar-pro |
| Context window | 1.1M | 128K |
| Max output | 128K | — |
| Input price | $2.00 / 1M tokens | $3.00 / 1M tokens |
| Output price | $12.00 / 1M tokens | $15.00 / 1M tokens |
| Knowledge cutoff | — | — |
| Input types | image, text | text, image, file |
| Output types | image, text | text |
| Plan | Premium | Premium |
Which should you use?
Pick GPT-5.6 Terra when…
- You need the larger context window — 1.1M against 128K.
- Cost matters: input runs at $2.00 / 1M tokens versus $3.00 / 1M tokens.
- You want longer single responses — up to 128K output tokens.
Related comparisons
Try both on Clade
You do not have to choose. One Clade subscription gives you GPT-5.6 Terra, Sonar Pro, and every other model on the platform.