Gemini 2.5 Flash Image Preview (Nano Banana) vs GPT-5.1-Codex: side-by-side summary

Gemini 2.5 Flash Image Preview (Nano Banana) and GPT-5.1-Codex are available through the OpenRouter API, so switching between them takes a model slug change rather than a new integration.

Gemini 2.5 Flash Image Preview (Nano Banana), from Google, has a 32,768-token context window and is priced by the provider serving it on OpenRouter.

GPT-5.1-Codex, from OpenAI, has a 400,000-token context window and is priced at $1.25/M tokens input, $10/M tokens output on OpenRouter.

Context window

• Gemini 2.5 Flash Image Preview (Nano Banana): 32,768 tokens
• GPT-5.1-Codex: 400,000 tokens

Price

• Gemini 2.5 Flash Image Preview (Nano Banana): Pricing varies by provider
• GPT-5.1-Codex: $1.25/M tokens input, $10/M tokens output

Provided by

• Gemini 2.5 Flash Image Preview (Nano Banana): Google
• GPT-5.1-Codex: OpenAI

• Gemini 2.5 Flash Image Preview (Nano Banana) model details, providers and pricing
• GPT-5.1-Codex model details, providers and pricing