Claude Opus 4.6 vs GPT-5.6 Terra
Anthropic against OpenAI, costed on the same three workloads. GPT-5.6 Terra is cheaper on all three workloads.
Monthly bill, side by side
| Workload | Claude Opus 4.6 | GPT-5.6 Terra | Difference |
|---|---|---|---|
| Support chatbot 2,500 six-turn conversations a day |
$20,138 | $8,865 | $11,273 (2.3×) |
| Document summariser 1,000 single-shot summaries a day |
$2,430 | $1,020 | $1,410 (2.4×) |
| Coding agent 200 twelve-turn sessions a day |
$14,040 | $5,976 | $8,064 (2.3×) |
No prompt caching and no batch discount on either side, so the comparison is like for like. Both figures assume 30 days a month.
The rate cards
| Claude Opus 4.6 | GPT-5.6 Terra | |
|---|---|---|
| Input, per 1M tokens | $5 | $2 |
| Output, per 1M tokens | $25 | $12 |
| Cached input | $0.5 | $0.2 |
| Context window | 1M | 1.05M |
| Maximum output | 128K | 128K |
| Reasoning model | yes | yes |
| Vision | yes | yes |
Run this comparison on your own numbers
Full detail: Claude Opus 4.6 pricing · GPT-5.6 Terra pricing