Gemini 4 Carbon vs GPT-5.5
Price in rupees, context and benchmarks side by side; same key, a one-string switch.
Scores from Epoch AI and LMArena, as published; a blank cell means not measured there.
What a month costs on each
On a typical 75/25 input-output mix, Gemini 4 Carbon costs less (about 64% less than GPT-5.5). GPT-5.5 takes the longer prompt at 1.1M tokens. Try your own numbers in the cost calculator.
Call either one
curl https://rapidrouter.ai/api/v1/chat/completions \
-H "Authorization: Bearer $RAPIDROUTER_API_KEY" \
-H "Content-Type: application/json" \
-d '{"model": "google/gemini-4-carbon", "messages": [{"role": "user", "content": "Hello"}]}'
# the other one: change the model string
-d '{"model": "openai/gpt-5.5", ...}'Common questions
Which is cheaper, Gemini 4 Carbon or GPT-5.5?
Gemini 4 Carbon is cheaper on a typical mix of 75% input and 25% output tokens, by about 64%. Through Rapid Router both are billed at the provider list price per million tokens, in rupees.
Which has the larger context window?
GPT-5.5, at 1.1M tokens. Gemini 4 Carbon offers 1M tokens.
Can I switch between Gemini 4 Carbon and GPT-5.5 without changing code?
Yes. Both are callable at https://rapidrouter.ai/api/v1 with the same OpenAI-compatible request; only the model string changes (google/gemini-4-carbon or openai/gpt-5.5).
How do I pay for Gemini 4 Carbon or GPT-5.5 in India?
Top up a Rapid Router balance with UPI or a card in rupees, get a GST invoice on every recharge, and both models debit that balance per request.