Compare Gemini 3.5 Flash from Google and GPT-5.6 Terra from OpenAI on key metrics including benchmarks, price, context length, and other model features. Access both models and hundreds of others through the OpenRouter API.
Gemini 3.5 Flash and GPT-5.6 Terra are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.
Gemini 3.5 Flash, from Google, has a 1,048,576-token context window and is priced at $1.50/M tokens input, $9/M tokens output on OpenRouter.
GPT-5.6 Terra, from OpenAI, has a 1,050,000-token context window and is priced at $2/M tokens input, $12/M tokens output on OpenRouter.
| Gemini 3.5 Flash | GPT-5.6 Terra | |
|---|---|---|
| Input price | $1.50/M tokens | $2/M tokens |
| Output price | $9/M tokens | $12/M tokens |
| Context window | 1,048,576 tokens | 1,050,000 tokens |
| Intelligence Index | 32.6 | 42.1 |
| Coding Index | 70.1 | 76.7 |
| Agentic Index | 26.0 | 43.2 |
| Latency (p50) | 15.55 s | 1.99 s |
| Throughput (p50) | 198.0 tok/s | 58.5 tok/s |
GPT-5.6 Terra has the longer context window at 1,050,000 tokens, compared with 1,048,576 tokens for Gemini 3.5 Flash.
Gemini 3.5 Flash is faster on OpenRouter, generating a median 198.0 tokens per second compared with 58.5 tokens per second for GPT-5.6 Terra.
GPT-5.6 Terra scores higher on coding, with an Artificial Analysis Coding Index of 76.7 compared with 70.1 for Gemini 3.5 Flash.