Claude Sonnet vs GPT Terra
The workhorse tier, where most production traffic actually runs. Both inherit their family's million-token context and both take $2 per million input tokens, but Sonnet 5.5 is now the cheaper of the two on output, $10 against $12. Sonnet keeps Claude's habit of matching an existing codebase; Terra keeps OpenAI's ecosystem breadth. For most teams this is a coin flip decided by existing integrations.
| Claude Sonnet | GPT Terra | |
|---|---|---|
| Provider | Anthropic | OpenAI |
| Current release | Sonnet 5.5 | GPT-5.6 Terra |
| Tier | Balanced | Balanced |
| Context | 1M | 1M |
| Cost | Moderate | Moderate |
| Modalities | text, vision | text, vision |
| Open weights | No | No |
Cost is a tier, not a quote, providers change prices often. Check Anthropic and OpenAI before you commit. Last updated 2026-10-21.
Which one to pick
Claude SonnetAnthropic · Sonnet 5.5
The default for most work, reads code like a senior engineer at a fair price
Reach for it when- Code generation inside an established repo
- Long conditional instructions that must be followed exactly
GPT TerraOpenAI · GPT-5.6 Terra
Production workloads that need frontier-family quality without the flagship bill
Reach for it when- Mixed text, image and audio workloads
- You want one vendor for the whole OpenAI tier ladder