Gemini 2.5 Pro vs OpenAI o3

Benchmarks, API pricing and specs, head to head. Data updated 2026-06-10.

Gemini 2.5 Pro

Google · Mar 2025

70.9

Google's 2025 workhorse flagship — first mainstream thinking model with a 1M context, still widely deployed.

OpenAI o3

OpenAI · Apr 2025

68.9

OpenAI's dedicated 2025 reasoning model that pioneered thinking-with-images and agentic tool use within chain-of-thought.

The verdict

OpenAI o3 wins 3 of the 5 benchmarks these models share, against 2 for Gemini 2.5 Pro. Gemini 2.5 Pro is about 1.0x cheaper per blended million tokens (3:1 input:output mix). Gemini 2.5 Pro also takes 1.0M of context versus 200K for OpenAI o3.

Benchmark head-to-head 23

SWE-bench Verified
63.8%69.1%
Gemini 2.5 ProOpenAI o3
GPQA Diamond
86.4%83.3%
Gemini 2.5 ProOpenAI o3
AIME 2025
88%88.9%
Gemini 2.5 ProOpenAI o3
HLE
21.6%20.3%
Gemini 2.5 ProOpenAI o3
MMMU
~79.6%82.9%
Gemini 2.5 ProOpenAI o3

Specs & pricing

Gemini 2.5 ProOpenAI o3
modhub Index70.968.9
Input price / 1M$1.25$2
Output price / 1M$10$8
Context window1.0M200K
Max output66K100K
Open weightsnono
Reasoning modelyesyes
Multimodal inputtext, image, audio, videotext, image
Knowledge cutoffJan 2025May 2024
ReleasedMar 2025Apr 2025
Example monthly cost*$27.50$32.00

* 10M input + 1.5M output tokens per month at list prices, no caching. Green = better value on that row.

Frequently asked questions

Which is better, Gemini 2.5 Pro or OpenAI o3?
OpenAI o3 wins 3 of the 5 benchmarks these models share, against 2 for Gemini 2.5 Pro. Gemini 2.5 Pro is about 1.0x cheaper per blended million tokens (3:1 input:output mix). Gemini 2.5 Pro also takes 1.0M of context versus 200K for OpenAI o3.
Which is cheaper, Gemini 2.5 Pro or OpenAI o3?
Gemini 2.5 Pro costs $1.25/$10 per million input/output tokens, while OpenAI o3 costs $2/$8. For a typical workload of 10M input and 1.5M output tokens per month, that's $27.50 versus $32.00.
Which model is better for coding, Gemini 2.5 Pro or OpenAI o3?
On SWE-bench Verified — the standard agentic-coding benchmark — OpenAI o3 scores 69.1% versus 63.8% for Gemini 2.5 Pro, making OpenAI o3 the stronger pick for coding agents.

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