GPT-5.6 Terra vs Gemini 3.6 Flash: the mid-tier workhorse pricing face-off
By TechCompare · Updated · How we check
On raw list price, Gemini 3.6 Flash is the cheaper workhorse across both input and output. Pick Terra only when OpenAI's reasoning quality or ecosystem justifies the premium. Switch to Gemini when you need native multimodal (image/audio/video) input.
OpenAI: GPT-5.6 Terra
OpenAI's own price
- Input
- $2
- Output
- $12
- Cached
- $0.20
per 1M tokens
Price checked 2026-11-12
Google: Gemini 3.6 Flash
Google AI Studio's own price
- Input
- $0.75
- Output
- $3.75
- Cached
- $0.075
per 1M tokens
Price checked 2026-11-12
Cost Comparison
Based on 100,000 input tokens (50% cached), 5,000 output tokens, and 100 requests.Prices come live from OpenRouter at each maker's own price where it's listed. Temporary deals are left out.
GPT-5.6 Terra and Gemini 3.6 Flash target the same high-volume production role, but Terra's list price is higher on both input and output. Gemini wins on raw per-token cost, while Terra's case rests on reasoning quality, the OpenAI ecosystem, and how much the workload values text-only performance.
Two mid-tier workhorses with different modality mixes. Compare list prices, caching, and fit.
Side-by-side specs
| Spec | GPT-5.6 Terra | Gemini 3.6 Flash |
|---|---|---|
| Input Cost (per M) | $2.00 | $0.75 (better on this spec) |
| Output Cost (per M) | $12.00 | $3.75 (better on this spec) |
| Cached Input (per M)Cached input is text the provider has already processed. It costs less than fresh input. | $0.20 | $0.075 (better on this spec) |
| Batch input / output (per M) | $1.00 / $6.00 | $0.375 / $1.875 |
| Native Audio/Video Input | No | Yes (better on this spec) |
| Context Window | 1.05M | 1.05M |
How they differ
GPT-5.6 Terra is priced at $2.00 per million input tokens and $12.00 per million output tokens at OpenAI's list price, with a 90% caching discount ($0.20 per million) and a 50% batch discount ($1.00/$6.00). Gemini 3.6 Flash is priced at $0.75 per million input tokens and $3.75 per million output tokens, with a 90% caching discount ($0.075 per million) and batch prices via the Google Batch API.
Gemini is 62.5% cheaper on input and 68.8% cheaper on output. Gemini 3.6 Flash's offsetting advantages are native image, audio, and video input support, plus a slightly larger 1.05M context window vs Terra's 1M.
Verdict
Flash is the cost default and Terra is the OpenAI-ecosystem pick. Flash is 62.5% cheaper on input ($0.75/M vs $2.00) and 68.8% cheaper on output ($3.75/M vs $12.00), and cached input keeps that lead at $0.075/M against $0.20/M. Batch takes the same share off both. Terra can't win a base price row here, and native audio/video input is Flash-only.
Which should you pick?
Choose GPT-5.6 Terra
Text-only workloads where OpenAI's reasoning quality or existing tooling ecosystem matters enough to justify the per-token premium over Gemini.
Choose Gemini 3.6 Flash
Workloads that need the lowest list-price per token, native audio or video input (transcription, video understanding, multimodal document analysis), or where Google's Batch API discount matters.