Model Comparison
Gemini 3 Flash vs o3Which is better in 2026?
Gemini 3 Flash significantly outperforms across most benchmarks. Gemini 3 Flash is 3.1x cheaper per token.
Verdict: Gemini 3 Flash vs o3 — which is better?
Gemini 3 Flash (by Google) and o3 (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.
Gemini 3 Flash outperforms in 8 benchmarks (AIME 2025, ARC-AGI v2, CharXiv-R, GPQA, Humanity's Last Exam, MMMU-Pro, SWE-Bench Verified, VideoMMMU), while o3 is better at 0 benchmarks. Gemini 3 Flash significantly outperforms across most benchmarks.
On price, Gemini 3 Flash is roughly 3.1x 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…
- you want the strongest raw capability — it leads on 8 of 8 shared benchmarks
- cost matters — it's about 3.1x 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 if…
- you want predictable pricing at $2.00/M input and $8.00/M output
Performance Benchmarks
Comparative analysis across standard metrics
Gemini 3 Flash outperforms in 8 benchmarks (AIME 2025, ARC-AGI v2, CharXiv-R, GPQA, Humanity's Last Exam, MMMU-Pro, SWE-Bench Verified, VideoMMMU), while o3 is better at 0 benchmarks.
Gemini 3 Flash significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, Gemini 3 Flash ($0.50/1M tokens) is 4.0x cheaper than o3 ($2.00/1M tokens).
For output processing, Gemini 3 Flash ($3.00/1M tokens) is 2.7x cheaper than o3 ($8.00/1M tokens).
In conclusion, o3 is more expensive than Gemini 3 Flash.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Gemini 3 Flash accepts 1,000,000 input tokens compared to o3's 200,000 tokens. o3 can generate longer responses up to 100,000 tokens, while Gemini 3 Flash is limited to 65,536 tokens.
Input Capabilities
Supported data types and modalities
Both Gemini 3 Flash and o3 support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
Gemini 3 Flash
o3
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
Gemini 3 Flash was released on 2025-12-17, while o3 was released on 2025-04-16.
Gemini 3 Flash is 8 months newer than o3.
Dec 17, 2025
5 months ago
8mo newerApr 16, 2025
1.1 years ago
Knowledge Cutoff
When training data ends
Gemini 3 Flash has a knowledge cutoff of 2025-01-31, while o3 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 (2024-05-31).
Jan 2025
8 mo newerMay 2024
Provider Availability
Gemini 3 Flash is available from Google. o3 is available from OpenAI.
Gemini 3 Flash
o3
Outputs Comparison
Key Takeaways
o3
View detailsOpenAI
No standout differentiators in the data we have for this pair.
Gemini 3 Flasho3Detailed Comparison
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FAQ
Common questions about Gemini 3 Flash vs o3.