Gemini 2.5 Pro vs GPT-4o: API pricing compared

Head-to-head on price — two widely deployed mainstays. On a mixed 10K-input / 2K-output request, Gemini 2.5 Pro is about 1.4× cheaper. The full picture below.

List prices side by side

Gemini 2.5 ProGPT-4o
ProviderGoogleOpenAI
Input $/MTok$1.25$2.5
Cached input $/MTok$0.125 (90% off)$1.25 (50% off)
Output $/MTok$10$10
Context window1024K tokens125K tokens
Max output64K tokens16K tokens

Gemini 2.5 Pro: Prompts over 200K tokens: $2.50 in / $15 out. Cache storage $4.50/MTok/hour.

What each costs in practice

WorkloadInputOutputGemini 2.5 ProGPT-4o
Short chat message500250$0.0031$0.0037
10-page document + summary7,000500$0.014$0.022
Agent / coding session50,00010,000$0.163$0.225
1M tokens in + 1M out1,000,0001,000,000$11.25$12.50

Price your exact token mix on each model's own page: the Gemini 2.5 Pro cost calculator and the GPT-4o cost calculator both take custom input/output counts and a requests-per-day figure.

About Gemini 2.5 Pro

Gemini 2.5 Pro was the model that established Google's thinking-model approach in general availability — Google describes it as the most advanced of the Gemini 2.5 family, built for complex tasks with deep reasoning and coding capability. It remains a stable, fully supported release with the family's signature range: multimodal input including audio and video, and a million-token-class context window.

With the Gemini 3 line above it, its role has shifted from frontier to known quantity — the version teams stay on when validated behaviour matters more than headline capability.

About GPT-4o

GPT-4o is OpenAI's omni-generation model, the first in its lineup designed from the start around multimodal input, and the ChatGPT default for a long stretch before the GPT-5 era. In the API it takes text and images and returns text, with a context window that is modest by later standards.

OpenAI keeps it available primarily for continuity: a large base of integrations was built against its exact behaviour, and like-for-like stability matters more there than headline capability. New work generally starts on the GPT-5 family, which OpenAI positions as its successor in every role GPT-4o played.

Frequently asked questions

Which is cheaper, Gemini 2.5 Pro or GPT-4o?

On a mixed workload (10K input / 2K output tokens per request), Gemini 2.5 Pro costs $0.033 per request versus $0.045 for GPT-4o — about 1.4× less. List rates: Gemini 2.5 Pro is $1.25/M input and $10/M output; GPT-4o is $2.5/M input and $10/M output.

What does a typical chat message cost on Gemini 2.5 Pro vs GPT-4o?

A short chat message (about 500 input and 250 output tokens) costs roughly $0.0031 with Gemini 2.5 Pro and $0.0037 with GPT-4o. At 1,000 messages a day that is about $93.75 versus $112.50 per month.

Do Gemini 2.5 Pro and GPT-4o have the same context window?

No. Gemini 2.5 Pro accepts up to 1024K tokens of input; GPT-4o accepts up to 125K. For workloads built around very large prompts, that difference can matter as much as the per-token rates.

Related

Compare all models at once ·Gemini 2.5 Pro pricing in detail ·GPT-4o pricing in detail ·Count tokens in your prompt

Last updated 2026-09-03. Prices verified against each provider's official pricing page; see the methodology.