Model Comparison
o3-mini vs DeepSeek-V2.5Which is better in 2026?
o3-mini significantly outperforms across most benchmarks. DeepSeek-V2.5 is 11.0x cheaper per token.
Verdict: o3-mini vs DeepSeek-V2.5 — which is better?
o3-mini (by OpenAI) and DeepSeek-V2.5 (by DeepSeek) 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.
o3-mini outperforms in 3 benchmarks (MATH, MMLU, SWE-Bench Verified), while DeepSeek-V2.5 is better at 0 benchmarks. o3-mini significantly outperforms across most benchmarks.
On price, DeepSeek-V2.5 is roughly 11.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
o3-mini also accepts a larger context window (200,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose o3-mini if…
- you want the strongest raw capability — it leads on 3 of 3 shared benchmarks
- you process long inputs — it offers a 200,000 token context window
- you want the most recent training data — it shipped Jan 2025
Choose DeepSeek-V2.5 if…
- cost matters — it's about 11.0x cheaper per token
- you need open weights you can self-host or fine-tune
Performance Benchmarks
Comparative analysis across standard metrics
o3-mini outperforms in 3 benchmarks (MATH, MMLU, SWE-Bench Verified), while DeepSeek-V2.5 is better at 0 benchmarks.
o3-mini significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, o3-mini ($1.10/1M tokens) is 7.9x more expensive than DeepSeek-V2.5 ($0.14/1M tokens).
For output processing, o3-mini ($4.40/1M tokens) is 15.7x more expensive than DeepSeek-V2.5 ($0.28/1M tokens).
In conclusion, o3-mini is more expensive than DeepSeek-V2.5.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
o3-mini accepts 200,000 input tokens compared to DeepSeek-V2.5's 8,192 tokens. o3-mini can generate longer responses up to 100,000 tokens, while DeepSeek-V2.5 is limited to 8,192 tokens.
License
Usage and distribution terms
o3-mini is licensed under a proprietary license, while DeepSeek-V2.5 uses deepseek.
License differences may affect how you can use these models in commercial or open-source projects.
Proprietary
Closed source
deepseek
Open weights
Release Timeline
When each model was launched
o3-mini was released on 2025-01-30, while DeepSeek-V2.5 was released on 2024-05-08.
o3-mini is 9 months newer than DeepSeek-V2.5.
Jan 30, 2025
1.5 years ago
8mo newerMay 8, 2024
2.2 years ago
Knowledge Cutoff
When training data ends
o3-mini has a documented knowledge cutoff of 2023-09-30, while DeepSeek-V2.5's cutoff date is not specified.
We can confirm o3-mini's training data extends to 2023-09-30, but cannot make a direct comparison without DeepSeek-V2.5's cutoff date.
Sep 2023
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Provider Availability
o3-mini is available from Azure, OpenAI. DeepSeek-V2.5 is available from DeepSeek, DeepInfra, Hyperbolic.
o3-mini
DeepSeek-V2.5
Outputs Comparison
Key Takeaways
o3-mini
View detailsOpenAI
DeepSeek-V2.5
View detailsDeepSeek
Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against o3-mini and DeepSeek-V2.5 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about o3-mini vs DeepSeek-V2.5.