GPT-6.1 Terra vs Gemini 3.8 Flash
GPT-6.1 Terra costs $1.00 / $5.00 and Gemini 3.8 Flash costs $0.75 / $3.75 per million input / output tokens. At a typical 3:1 mix, Gemini 3.8 Flash is 1.3× cheaper than GPT-6.1 Terra. Gemini 3.8 Flash's price is promotional: $0.75 / $3.75 until 31 Dec 2026, then $1.50 / $7.50.
Input
$1.00
per 1M
Output
$5.00
per 1M
Cached
$0.050
1.05M context
Input
$0.75
per 1M
Output
$3.75
per 1M
Cached
$0.075
1M context
Side by side
✓ marks the cheaper price, larger context window, bigger discount or higher score.
| Detail | GPT-6.1 Terra | Gemini 3.8 Flash |
|---|---|---|
| Price per 1M tokens | ||
| Input | $1.00 | $0.75Lowest |
| Output | $5.00 | $3.75Lowest |
| Blended (3 in : 1 out) | $2.00 | $1.50Lowest |
| Cached input | $0.050Lowest | $0.075 |
| Batch or off-peak discount | 50% (batch) | 50% (batch) |
| Long prompts | Over 272K: 2× in, 1.5× out | Same rate at any length |
| Limits and model | ||
| Context window | 1.05MLargest | 1M |
| Capability score Epoch AI index | 168Highest | 158 |
| Arena text score 25 Sep 2026 | — | 1492 |
| Released | 26 Oct 2026 | 2 Sep 2026 |
| Open weights | No | No |
| Status | Current | Current |
| Checked | ||
| Price checked | 2 Nov 2026 OpenAI pricing | 6 Nov 2026 Gemini API pricing |
Monthly cost on three workloads
List prices, no batch discount. The cached share applies where a model has a cache rate.
| Workload | GPT-6.1 Terra | Gemini 3.8 Flash | Difference |
|---|---|---|---|
| Customer chat assistant50,000 conversations a month, about 2,000 tokens in and 400 out each; 50% cachedPrice this workload in the calculator | $153 | $116Lower | $36.25 |
| Document Q&A (RAG)20,000 questions a month over retrieved documents, 12,000 in and 600 out; 30% cachedPrice this workload in the calculator | $232 | $176Lower | $55.20 |
| Coding agent400 tasks a month, 40 steps each with a growing context; 85% cachedPrice this workload in the calculator | $184 | $162Lower | $22.19 |
How they differ
- Gemini 3.8 Flash is cheaper on input ($0.75 vs $1).
- Gemini 3.8 Flash is cheaper on output ($3.75 vs $5), which matters most for long answers and reasoning models.
- GPT-6.1 Terra accepts longer prompts (1.05M vs 1M tokens).
- Cached input is cheaper on GPT-6.1 Terra ($0.05 vs $0.075), which favours agents and chat apps that resend the same context.
- On Epoch AI’s Capabilities Index, GPT-6.1 Terra scores clearly higher (168 vs 158), beyond the margin of error.
Recent changes
All changes- OpenAI launched GPT-6.1 Terra at $1 / $5 per 1M tokens, with cached input at $0.05: half the price of GPT-6.1 Sol.
- GPT-6.1 Sol replaced GPT-6 Sol at the same $2 / $10 per 1M tokens, with cached input cut from $0.20 to $0.10.
- OpenAI launched GPT-6 Sol at $2 / $10 and GPT-6 Luna at $0.10 / $0.50.
- OpenAI launched GPT-6 Astra at $10 / $50, its most expensive standard model.
- Google launched Gemini 3.8 Flash at $0.75 / $3.75 until 31 December, then $1.50 / $7.50.
Related comparisons
Compare up to four
GPT-6.1 Terra vs Claude Sonnet 5.5$1.00 / $5.00 · $2.00 / $10.00
Qwen3.8 Max vs Gemini 3.8 Flash$2.00 / $6.00 · $0.75 / $3.75- Gemini 3.8 Flash vs GPT-6.1 Sol$0.75 / $3.75 · $2.00 / $10.00
- Gemini 3.8 Flash vs Claude Haiku 5.5$0.75 / $3.75 · $0.10 / $0.50
- Claude Sonnet 5.5 vs Gemini 3.8 Flash$2.00 / $10.00 · $0.75 / $3.75