Comparison

Gemini 3.5 Flash vs GPT-5.5

GPT-5.5 charges 70% more per input token than Gemini 3.5 Flash. Output pricing favors Gemini 3.5 Flash, 70% less per token than GPT-5.5. GPT-5.5 has the larger context window than Gemini 3.5 Flash.

FieldGemini 3.5 Flash
GPT-5.5
ProviderGoogleOpenAI
Context window1M1.1M
Max output65.5K128K
Input / 1M$1.5070% cheaper$5.00
Output / 1M$9.0070% cheaper$30.00
Cached input / 1M$0.1570% cheaper$0.50
Batch discount50%50%
Release date2026-04-23

Worked cost examples

Estimated monthly cost on three common usage shapes

WorkloadGemini 3.5 FlashGPT-5.5

Chatbot

800 input / 200 output tokens per request, 100,000 requests/month

$300.00cheaper$1,000

RAG pipeline

6,000 input / 700 output tokens per request, 30,000 requests/month

$459.00cheaper$1,530

Batch summarization

20,000 input / 1,500 output tokens per request, 5,000 requests/month

$217.50cheaper$725.00

Gemini 3.5 Flash vs GPT-5.5 FAQ

Is Gemini 3.5 Flash cheaper than GPT-5.5?
Gemini 3.5 Flash costs $1.50 per 1M input tokens versus $5.00 for GPT-5.5 — Gemini 3.5 Flash is 70% cheaper per input token.
Which is cheaper for output tokens, Gemini 3.5 Flash or GPT-5.5?
Gemini 3.5 Flash charges $9.00 per 1M output tokens; GPT-5.5 charges $30.00 per 1M output tokens.
Which has the larger context window, Gemini 3.5 Flash or GPT-5.5?
GPT-5.5 does, with a 1,050,000-token context window.
Do Gemini 3.5 Flash and GPT-5.5 offer cache pricing?
Gemini 3.5 Flash discounts cached input to $0.15 per 1M tokens. GPT-5.5 discounts cached input to $0.50 per 1M tokens.

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