Model Comparison

Gemini 3 Flash vs o3-proWhich is better in 2026?

Comparing Gemini 3 Flash and o3-pro across benchmarks, pricing, and capabilities.

Verdict: Gemini 3 Flash vs o3-pro — which is better?

Gemini 3 Flash (by Google) and o3-pro (by OpenAI) are two of the AI models people compare most. Here is how they stack up on benchmarks, price and capabilities, and which one to pick in 2026.

On price, Gemini 3 Flash is roughly 31.1x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.

Gemini 3 Flash also accepts a larger context window (1,000,000 input tokens), making it the stronger choice for long documents and large codebases.

Choose Gemini 3 Flash if…

  • cost matters — it's about 31.1x cheaper per token
  • you process long inputs — it offers a 1,000,000 token context window
  • you want the most recent training data — it shipped Dec 2025

Choose o3-pro if…

  • you want predictable pricing at $20.00/M input and $80.00/M output
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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Gemini 3 Flash and o3-prodon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Gemini 3 Flash costs less

For input processing, Gemini 3 Flash ($0.50/1M tokens) is 40.0x cheaper than o3-pro ($20.00/1M tokens).

For output processing, Gemini 3 Flash ($3.00/1M tokens) is 26.7x cheaper than o3-pro ($80.00/1M tokens).

In conclusion, o3-pro is more expensive than Gemini 3 Flash.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Sat Jun 13 2026 • llm-stats.com
Google
Gemini 3 Flash
Input tokens$0.50
Output tokens$3.00
Best providerGoogle
OpenAI
o3-pro
Input tokens$20.00
Output tokens$80.00
Best providerOpenAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Gemini 3 Flash accepts 1,000,000 input tokens compared to o3-pro's 200,000 tokens. o3-pro can generate longer responses up to 100,000 tokens, while Gemini 3 Flash is limited to 65,536 tokens.

Google
Gemini 3 Flash
Input1,000,000 tokens
Output65,536 tokens
OpenAI
o3-pro
Input200,000 tokens
Output100,000 tokens
Sat Jun 13 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Both Gemini 3 Flash and o3-pro support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

Gemini 3 Flash

Text
Images
Audio
Video

o3-pro

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Gemini 3 Flash

Proprietary

Closed source

o3-pro

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 3 Flash was released on 2025-12-17, while o3-pro was released on 2025-06-10.

Gemini 3 Flash is 6 months newer than o3-pro.

Gemini 3 Flash

Dec 17, 2025

5 months ago

6mo newer
o3-pro

Jun 10, 2025

1.0 years ago

Knowledge Cutoff

When training data ends

Gemini 3 Flash has a knowledge cutoff of 2025-01-31, while o3-pro has a cutoff of 2024-05-31.

Gemini 3 Flash has more recent training data (up to 2025-01-31), making it potentially better informed about events through that date compared to o3-pro (2024-05-31).

Gemini 3 Flash

Jan 2025

8 mo newer
o3-pro

May 2024

Provider Availability

Gemini 3 Flash is available from Google. o3-pro is available from OpenAI.

Gemini 3 Flash

google logo
Google
Input Price:Input: $0.50/1MOutput Price:Output: $3.00/1M

o3-pro

openai logo
OpenAI
Input Price:Input: $20.00/1MOutput Price:Output: $80.00/1M
* Prices shown are per million tokens

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

Google
Larger context window (1,000,000 tokens)
Less expensive input tokens
Less expensive output tokens
OpenAI

No standout differentiators in the data we have for this pair.

Detailed Comparison

AI Model Comparison Table
Feature
Google
Gemini 3 Flash
OpenAI
o3-pro

FAQ

Common questions about Gemini 3 Flash vs o3-pro.

Which is better, Gemini 3 Flash or o3-pro?

Gemini 3 Flash (Google) and o3-pro (OpenAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Gemini 3 Flash compare to o3-pro in benchmarks?

Gemini 3 Flash scores Vending-Bench 2: 100.0%, AIME 2025: 99.7%, Global PIQA: 92.8%, MMMLU: 91.8%, GPQA: 90.4%.

Is Gemini 3 Flash cheaper than o3-pro?

Gemini 3 Flash is 40.0x cheaper for input tokens. Gemini 3 Flash costs $0.50/M input and $3.00/M output via google. o3-pro costs $20.00/M input and $80.00/M output via openai.

What are the context window sizes for Gemini 3 Flash and o3-pro?

Gemini 3 Flash supports 1.0M tokens and o3-pro supports 200K tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 3 Flash and o3-pro?

Key differences include context window (1.0M vs 200K), input pricing ($0.50 vs $20.00/M). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 3 Flash and o3-pro?

Gemini 3 Flash is developed by Google and o3-pro is developed by OpenAI.

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