Prices → Compare → GPT-5.6 Terra vs Gemini 3.7 Flash
GPT-5.6 Terra vs Gemini 3.7 Flash: API cost compared
GPT-5.6 Terra lists at $1.000 in / $6.000 out per 1M tokens. Gemini 3.7 Flash lists at $0.750 in / $3.750. Sticker price only tells you so much — below is what each actually costs across eight production workloads.
Side by side
| GPT-5.6 Terra | Gemini 3.7 Flash | |
|---|---|---|
| Provider | OpenAI | |
| Input per 1M | $1.000 | $0.750 |
| Output per 1M | $6.000 | $3.750 |
| Cached input per 1M | $0.100 | not published |
| Context window | 400k | 1M |
| Blended per 1M (3:1) | $2.250 | $1.500 |
Monthly cost by workload
Caching applied at each workload's typical hit rate. This is where the two models actually separate.
| Workload | GPT-5.6 Terra | Gemini 3.7 Flash | Cheaper | Difference |
|---|---|---|---|---|
| Customer support chatbot | $146.40 | $133.12 | Gemini 3.7 Flash | $13.28 (9%) |
| RAG document Q&A | $196.00 | $165.00 | Gemini 3.7 Flash | $31.00 (16%) |
| Coding agent | $104.50 | $120.00 | GPT-5.6 Terra | $15.50 (13%) |
| Bulk summarization | $1,386 | $1,050 | Gemini 3.7 Flash | $336.00 (24%) |
| Structured data extraction | $1,870 | $1,781 | Gemini 3.7 Flash | $88.75 (5%) |
| Long-form content generation | $254.60 | $165.00 | Gemini 3.7 Flash | $89.60 (35%) |
| Email triage agent | $432.50 | $487.50 | GPT-5.6 Terra | $55.00 (11%) |
| Translation pipeline | $1,645 | $1,069 | Gemini 3.7 Flash | $576.00 (35%) |
How to read this
Gemini 3.7 Flash is cheaper on the majority of these workloads, but "majority" is not the decision. The output:input price ratio is 6.0 for GPT-5.6 Terra and 5.0 for Gemini 3.7 Flash. If your traffic is output-heavy — long-form drafting, translation — the model with the lower output price wins regardless of what the input price suggests. If you are input-heavy — RAG, bulk summarization, agents re-reading a codebase — the cached input rate matters more than either headline number.
Cost is also not the only axis. This site does not benchmark quality, latency, or rate limits, and a model that is 3x cheaper but needs two attempts per task is not cheaper. Use these numbers to size a bill, then validate on your own evals.
Run your own numbers
Cost calculator
Enter your own numbers, or start from a workload preset. Costs are monthly and update as you type.
| Model | In /1M | Out /1M | Monthly | vs best |
|---|