DeepSeek-R1 vs GPT-5.1 Codex
Comparing DeepSeek-R1 and GPT-5.1 Codex across benchmarks, pricing, and capabilities.
DeepSeek · OpenAI · Updated for 2026
Which is better?
DeepSeek-R1 and GPT-5.1 Codex trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
On price, DeepSeek-R1 is roughly 3.6x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
GPT-5.1 Codex also accepts a larger context window (400,000 input tokens), making it the stronger choice for long documents and large codebases.
Based on current benchmark, pricing, and model metadata for 2026.
Choose DeepSeek-R1
- cost matters — it's about 3.6x cheaper per token
- you need open weights you can self-host or fine-tune
Choose GPT-5.1 Codex
- you process long inputs — it offers a 400,000 token context window
- you want the most recent training data — it shipped Nov 2025
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
DeepSeek-R1 and GPT-5.1 Codexdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Arena Performance
Playground indexes and blind preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, DeepSeek-R1 ($0.55/1M tokens) is 2.3x cheaper than GPT-5.1 Codex ($1.25/1M tokens).
For output processing, DeepSeek-R1 ($2.19/1M tokens) is 4.6x cheaper than GPT-5.1 Codex ($10.00/1M tokens).
In conclusion, GPT-5.1 Codex is more expensive than DeepSeek-R1.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
GPT-5.1 Codex accepts 400,000 input tokens compared to DeepSeek-R1's 131,072 tokens. DeepSeek-R1 can generate longer responses up to 131,072 tokens, while GPT-5.1 Codex is limited to 128,000 tokens.
Input Capabilities
Supported data types and modalities
GPT-5.1 Codex supports multimodal inputs, whereas DeepSeek-R1 does not.
GPT-5.1 Codex can handle both text and other forms of data like images, making it suitable for multimodal applications.
DeepSeek-R1
GPT-5.1 Codex
License
Usage and distribution terms
DeepSeek-R1 is licensed under MIT, while GPT-5.1 Codex 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-R1 was released on 2025-01-20, while GPT-5.1 Codex was released on 2025-11-19.
GPT-5.1 Codex is 10 months newer than DeepSeek-R1.
Jan 20, 2025
1.6 years ago
Nov 19, 2025
9 months ago
10mo newerKnowledge Cutoff
When training data ends
GPT-5.1 Codex has a documented knowledge cutoff of 2024-09-30, while DeepSeek-R1's cutoff date is not specified.
We can confirm GPT-5.1 Codex's training data extends to 2024-09-30, but cannot make a direct comparison without DeepSeek-R1's cutoff date.
—
Sep 2024
Provider Availability
DeepSeek-R1 is available from DeepSeek, DeepInfra, Together, Fireworks. GPT-5.1 Codex is available from OpenAI.
DeepSeek-R1
GPT-5.1 Codex
Outputs Comparison
Judge for yourself.
Run your own prompts against DeepSeek-R1 and GPT-5.1 Codex side-by-side, then vote on the output you prefer.
FAQ
Common questions about DeepSeek-R1 vs GPT-5.1 Codex.