GPT-5.6 Terra Paid vs 
Gemini 3.8 Flash Paid
GPT-5.6 Terra vs Gemini 3.8 Flash compared — price per token, context window, multimodality, openness and which to choose. Full 2026 breakdown.
GPT-5.6 Terra — full profile › · Gemini 3.8 Flash — full profile ›
Prices & specs refreshed from live data · olud.ai
Open-model prices = cheapest provider via OpenRouter; official maker rates may be higher.
$12 /M outputManaged API (no infra to run)
$3.75 /M outputManaged API (no infra to run)
GPT-5.6 Terra vs Gemini 3.8 Flash specs
| Spec | GPT-5.6 Terra | Gemini 3.8 Flash | Winner |
|---|---|---|---|
| Maker | OpenAI | – | |
| Type | Proprietary | Proprietary | – |
| Context window | 1.1M tokens | 1M tokens | |
| Input price | $2/M | $0.75/M | |
| Output price | $12/M | $3.75/M | |
| Vision / multimodal | Yes | Yes | = Tie |
| Tool / function calling | Yes | Yes | = Tie |
| Self-hostable | No (API only) | No (API only) | – |
| License | Proprietary | Proprietary | – |
Price gap & when to choose each
Gemini 3.8 Flash is ~3.2× cheaper than GPT-5.6 Terra on output tokens ($3.75 vs $12 per M tokens).
- You want frontier performance through a managed API
- You need the longer 1.1M context window
- You value reliability & ecosystem
- You don't want to manage infrastructure
- You want frontier performance through a managed API
- You want the lower output price
- You value reliability & ecosystem
- You don't want to manage infrastructure
Feature comparison
| Capability | GPT-5.6 Terra | Gemini 3.8 Flash |
|---|---|---|
| Open weights (downloadable) | ✗ | ✗ |
| Self-hostable | ✗ | ✗ |
| Runs fully offline | ✗ | ✗ |
| Vision / multimodal | ✓ | ✓ |
| Tool / function calling | ✓ | ✓ |
| 1M+ context window | ✓ | ✓ |
Benchmarks: GPT-5.6 Terra vs Gemini 3.8 Flash
Independent benchmark scores measured by Artificial Analysis. Higher is better (except latency).
Benchmark data by Artificial Analysis.
How GPT-5.6 Terra and Gemini 3.8 Flash score
| Criterion | GPT-5.6 Terra | Gemini 3.8 Flash |
|---|---|---|
| Cost-efficiency | 3.5 | 4.0 |
| Context window | 5.0 | 5.0 |
| Openness | 1.5 | 1.5 |
| Self-hosting | 1.0 | 1.0 |
| Multimodality | 5.0 | 5.0 |
Scores come from live data — output price (cost), context length, open vs closed weights (openness & self-hosting) and vision/tool support (multimodality). Raw task quality isn't scored here; it depends on your benchmark — see the verdict.
What each model is
GPT-5.6 Terra Paid
GPT-5.6 Terra is a balanced model in OpenAI's GPT-5.6 series, positioned between the flagship Sol tier and the cost-efficient Luna tier. It is suited for everyday coding, reasoning, and agentic...
Gemini 3.8 Flash Paid
Gemini 3.8 Flash is Google's most intelligent Flash model with significant gains from 3.7 Flash across software engineering, agentic tasks, and multi-step reasoning.
Other models in these families
These variants are tracked but not compared here — one page per family keeps the comparison readable.
Frequently asked questions
GPT-5.6 Terra vs Gemini 3.8 Flash — which is cheaper?
Gemini 3.8 Flash is cheaper on output ($3.75/M vs $12/M).
Which has the larger context window?
GPT-5.6 Terra offers the larger context window (1.1M tokens).
GPT-5.6 Terra vs Gemini 3.8 Flash — which should I pick in 2026?
Choose Gemini 3.8 Flash for the lower output price ($3.75/M vs $12/M). Choose GPT-5.6 Terra if you need the larger 1.1M context window.
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