Gemini 3.5 Flash vs GPT-4o
google/gemini-3.5-flash · openai/gpt-4o
As of October 25, 2026, GPT-4o is the cheaper API on UberLLM: $0.2500 per million input tokens and $1.00 per million output, versus $0.3450 / $2.07 for Gemini 3.5 Flash — about 50% less on a blended 3:1 token mix. Both are reached through one OpenAI-compatible key and routed to the cheapest healthy seller, with no UberLLM fee added, so the price you see is the price you pay. Choose GPT-4o to cut cost; choose Gemini 3.5 Flash when context size wins — Gemini 3.5 Flash carries the larger context window (1,048,576 vs 128,000 tokens), which can matter for long-document work.
Gemini 3.5 Flash vs GPT-4o, side by side
| Spec | Gemini 3.5 Flash | GPT-4o |
|---|---|---|
| Price · input / 1M | $0.3450 | $0.2500 |
| Price · output / 1M | $2.07 | $1.00 |
| Context length | 1,048,576 | 128,000 |
| Max output tokens | 65,536 | 16,384 |
| Input modalities | text | text |
| Output modalities | text | text |
| Tools / functions | Yes | Yes |
| Cheapest seller | UberLLM | UberLLM |
| % off list | 77% off | 90% off |
Live prices via UberLLM, routed to the cheapest healthy seller. The price shown has no UberLLM fee added. Updated October 25, 2026.
Gemini 3.5 Flash vs GPT-4o — FAQ
Is Gemini 3.5 Flash or GPT-4o cheaper?
GPT-4o is cheaper on a blended token mix, by about 50%. UberLLM routes every request to the cheapest healthy seller and bills the price shown, with no fee added.
What's the price difference between Gemini 3.5 Flash and GPT-4o?
Gemini 3.5 Flash: $0.3450 in / $2.07 out per 1M tokens. GPT-4o: $0.2500 in / $1.00 out per 1M tokens. That's roughly a 50% blended difference. Prices are live; UberLLM adds no fee.
Can I use both Gemini 3.5 Flash and GPT-4o with one API?
Yes. Both are served through a single OpenAI-compatible endpoint — set the base URL to https://api.uberllm.dev/v1 and your UberLLM key, then switch between them by changing the model id. Anthropic SDKs work via https://api.uberllm.dev/v1/messages.