Model Comparison
DeepSeek-V3.1 vs o3Which is better in 2026?
o3 significantly outperforms across most benchmarks. DeepSeek-V3.1 is 7.7x cheaper per token.
Verdict: DeepSeek-V3.1 vs o3 — which is better?
DeepSeek-V3.1 (by DeepSeek) 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.
DeepSeek-V3.1 outperforms in 1 benchmarks (Humanity's Last Exam), while o3 is better at 6 benchmarks (Aider-Polyglot, AIME 2024, AIME 2025, BrowseComp, GPQA, SWE-Bench Verified). o3 significantly outperforms across most benchmarks.
On price, DeepSeek-V3.1 is roughly 7.7x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
o3 also accepts a larger context window (200,000 input tokens), making it the stronger choice for long documents and large codebases.
Choose DeepSeek-V3.1 if…
- cost matters — it's about 7.7x cheaper per token
- you need open weights you can self-host or fine-tune
Choose o3 if…
- you want the strongest raw capability — it leads on 6 of 7 shared benchmarks
- you process long inputs — it offers a 200,000 token context window
- you want the most recent training data — it shipped Apr 2025
Performance Benchmarks
Comparative analysis across standard metrics
DeepSeek-V3.1 outperforms in 1 benchmarks (Humanity's Last Exam), while o3 is better at 6 benchmarks (Aider-Polyglot, AIME 2024, AIME 2025, BrowseComp, GPQA, SWE-Bench Verified).
o3 significantly outperforms across most benchmarks.
Arena Performance
Human preference votes
Pricing Analysis
Price comparison per million tokens
For input processing, DeepSeek-V3.1 ($0.27/1M tokens) is 7.4x cheaper than o3 ($2.00/1M tokens).
For output processing, DeepSeek-V3.1 ($1.00/1M tokens) is 8.0x cheaper than o3 ($8.00/1M tokens).
In conclusion, o3 is more expensive than DeepSeek-V3.1.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
o3 accepts 200,000 input tokens compared to DeepSeek-V3.1's 163,840 tokens. DeepSeek-V3.1 can generate longer responses up to 163,840 tokens, while o3 is limited to 100,000 tokens.
Input Capabilities
Supported data types and modalities
o3 supports multimodal inputs, whereas DeepSeek-V3.1 does not.
o3 can handle both text and other forms of data like images, making it suitable for multimodal applications.
DeepSeek-V3.1
o3
License
Usage and distribution terms
DeepSeek-V3.1 is licensed under MIT, while o3 uses a proprietary license.
License differences may affect how you can use these models in commercial or open-source projects.
MIT
Open weights
Proprietary
Closed source
Release Timeline
When each model was launched
DeepSeek-V3.1 was released on 2025-01-10, while o3 was released on 2025-04-16.
o3 is 3 months newer than DeepSeek-V3.1.
Jan 10, 2025
1.5 years ago
Apr 16, 2025
1.2 years ago
3mo newerKnowledge Cutoff
When training data ends
o3 has a documented knowledge cutoff of 2024-05-31, while DeepSeek-V3.1's cutoff date is not specified.
We can confirm o3's training data extends to 2024-05-31, but cannot make a direct comparison without DeepSeek-V3.1's cutoff date.
—
May 2024
Provider Availability
DeepSeek-V3.1 is available from DeepInfra, Novita. o3 is available from OpenAI.
DeepSeek-V3.1
o3
Outputs Comparison
Key Takeaways
DeepSeek-V3.1
View detailsDeepSeek
o3
View detailsOpenAI
DeepSeek-V3.1o3Detailed Comparison
Interactive Arena
Judge for yourself.
Run your own prompts against DeepSeek-V3.1 and o3 side-by-side, then vote on the output you prefer.
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FAQ
Common questions about DeepSeek-V3.1 vs o3.