Gemini 2.5 Pro vs GPT-4o: pricing & cost comparison
On input tokens, Gemini 2.5 Pro is the cheaper of the two — 50% less per million ($1.25 vs $2.5). Both charge $10 per million output tokens.
Side by side
| Gemini 2.5 Pro | GPT-4o | |
|---|---|---|
| Input / 1M tokens | $1.25 | $2.5 |
| Output / 1M tokens | $10 | $10 |
| Context window | 1,000,000 | 128,000 |
| Token-count accuracy | ±3% | exact |
| Cost — 10,000 input + 2,000 output tokens | $0.0325 | $0.045 |
What a real request costs
Take a representative turn — 10,000 input + 2,000 output tokens. Gemini 2.5 Pro comes to $0.0325, GPT-4o to $0.045. Across 100,000 requests that's a $1250 swing in favour of Gemini 2.5 Pro. To run the numbers on your actual prompt, paste it into the calculator and toggle Compare across all models.
Close call — decide on output cost
Gemini 2.5 Pro and GPT-4o are close enough on price that the tie-breakers matter more than the headline rate. Output tokens are usually the dominant cost driver, so weigh $10 vs $10 per 1M output first, then context window — Gemini 2.5 Pro carries the larger one at 1,000,000 tokens. They're different vendors, so factor in a small tokenizer calibration buffer on whichever side isn't exact.
See the full breakdown on the dedicated pages for Gemini 2.5 Pro and GPT-4o.
FAQ
- Is Gemini 2.5 Pro or GPT-4o cheaper?
- For a typical request (10,000 input + 2,000 output tokens), Gemini 2.5 Pro is cheaper — about 28% less, or roughly $1250 saved per 100,000 requests. Gemini 2.5 Pro runs $1.25/$10 per 1M input/output tokens; GPT-4o runs $2.5/$10.
- Which has the larger context window?
- Gemini 2.5 Pro, at 1,000,000 tokens versus 128,000.
- How accurate are these token counts?
- Gemini 2.5 Pro: Approximated with o200k_base; drift typically ~3% on English and code. GPT-4o: Exact tokenization via the canonical OpenAI vocab (o200k_base). The dollar math itself is exact once the token count is known.
Both prices are computed from tokenmath's verified pricing table. Rates sourced from ai.google.dev and openai.com, verified 2026-05-18. Vendor pricing changes often — confirm before you commit.