Gemini 2.5 Flash vs OpenAI o4-mini

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

Gemini 2.5 Flash

Google · Jun 2025

The 2025 fast-tier favorite: hybrid reasoning, full multimodality and a 1M context at $0.30/$2.50.

OpenAI o4-mini

OpenAI · Apr 2025

80.9

A compact reasoning model that punched far above its price on math — 92.7% on AIME 2025 at $1.10 per million input tokens.

The verdict

OpenAI o4-mini wins 3 of the 3 benchmarks these models share, against 0 for Gemini 2.5 Flash. Gemini 2.5 Flash is about 2.3x cheaper per blended million tokens (3:1 input:output mix). Gemini 2.5 Flash also takes 1.0M of context versus 200K for OpenAI o4-mini.

Benchmark head-to-head 03

SWE-bench Verified
~48.9%68.1%
Gemini 2.5 FlashOpenAI o4-mini
GPQA Diamond
~78.3%81.4%
Gemini 2.5 FlashOpenAI o4-mini
MMMU
~76.9%81.6%
Gemini 2.5 FlashOpenAI o4-mini

Specs & pricing

Gemini 2.5 FlashOpenAI o4-mini
modhub Index80.9
Input price / 1M$0.3$1.1
Output price / 1M$2.5$4.4
Context window1.0M200K
Max output66K100K
Open weightsnono
Reasoning modelyesyes
Multimodal inputtext, image, audio, videotext, image
Knowledge cutoffJan 2025May 2024
ReleasedJun 2025Apr 2025
Example monthly cost*$6.75$17.60

* 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 Flash or OpenAI o4-mini?
OpenAI o4-mini wins 3 of the 3 benchmarks these models share, against 0 for Gemini 2.5 Flash. Gemini 2.5 Flash is about 2.3x cheaper per blended million tokens (3:1 input:output mix). Gemini 2.5 Flash also takes 1.0M of context versus 200K for OpenAI o4-mini.
Which is cheaper, Gemini 2.5 Flash or OpenAI o4-mini?
Gemini 2.5 Flash costs $0.3/$2.5 per million input/output tokens, while OpenAI o4-mini costs $1.1/$4.4. For a typical workload of 10M input and 1.5M output tokens per month, that's $6.75 versus $17.60.
Which model is better for coding, Gemini 2.5 Flash or OpenAI o4-mini?
On SWE-bench Verified — the standard agentic-coding benchmark — OpenAI o4-mini scores 68.1% versus ~48.9% for Gemini 2.5 Flash, making OpenAI o4-mini the stronger pick for coding agents.

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