DeepSeek-V4-Pro-0813 vs Grok-4.1 Fast Reasoning
Comparing DeepSeek-V4-Pro-0813 and Grok-4.1 Fast Reasoning across benchmarks, pricing, and capabilities.
DeepSeek · xAI · Updated for 2026
Which is better?
DeepSeek-V4-Pro-0813 and Grok-4.1 Fast Reasoning trade strengths across price, capabilities, and technical limits. The better choice depends on the workload.
On price, Grok-4.1 Fast Reasoning is roughly 2.0x cheaper per token on a blended 3:1 input/output basis, which adds up quickly at production volume.
Grok-4.1 Fast Reasoning also accepts a larger context window (2,000,000 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-V4-Pro-0813
- you want the most recent training data — it shipped Aug 2026
- you need open weights you can self-host or fine-tune
Choose Grok-4.1 Fast Reasoning
- cost matters — it's about 2.0x cheaper per token
- you process long inputs — it offers a 2,000,000 token context window
At a glance
The differences that matter most.
Performance Benchmarks
Comparative analysis across standard metrics
DeepSeek-V4-Pro-0813 and Grok-4.1 Fast Reasoningdon'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-V4-Pro-0813 ($0.43/1M tokens) is 2.2x more expensive than Grok-4.1 Fast Reasoning ($0.20/1M tokens).
For output processing, DeepSeek-V4-Pro-0813 ($0.87/1M tokens) is 1.7x more expensive than Grok-4.1 Fast Reasoning ($0.50/1M tokens).
In conclusion, DeepSeek-V4-Pro-0813 is more expensive than Grok-4.1 Fast Reasoning.*
* Using a 3:1 ratio of input to output tokens
Context Window
Maximum input and output token capacity
Grok-4.1 Fast Reasoning accepts 2,000,000 input tokens compared to DeepSeek-V4-Pro-0813's 1,048,576 tokens. DeepSeek-V4-Pro-0813 can generate longer responses up to 393,216 tokens, while Grok-4.1 Fast Reasoning is limited to 30,000 tokens.
Input Capabilities
Supported data types and modalities
Grok-4.1 Fast Reasoning supports multimodal inputs, whereas DeepSeek-V4-Pro-0813 does not.
Grok-4.1 Fast Reasoning can handle both text and other forms of data like images, making it suitable for multimodal applications.
DeepSeek-V4-Pro-0813
Grok-4.1 Fast Reasoning
License
Usage and distribution terms
DeepSeek-V4-Pro-0813 is licensed under MIT, while Grok-4.1 Fast Reasoning 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-V4-Pro-0813 was released on 2026-08-13, while Grok-4.1 Fast Reasoning was released on 2025-11-17.
DeepSeek-V4-Pro-0813 is 9 months newer than Grok-4.1 Fast Reasoning.
Aug 13, 2026
1 weeks ago
8mo newerNov 17, 2025
9 months ago
Knowledge Cutoff
When training data ends
Neither model specifies a knowledge cutoff date.
Unable to compare the recency of their training data.
Provider Availability
DeepSeek-V4-Pro-0813 is available from DeepSeek, DeepInfra, Novita, Together. Grok-4.1 Fast Reasoning is available from xAI.
DeepSeek-V4-Pro-0813
Grok-4.1 Fast Reasoning
Outputs Comparison
Judge for yourself.
Run your own prompts against DeepSeek-V4-Pro-0813 and Grok-4.1 Fast Reasoning side-by-side, then vote on the output you prefer.
FAQ
Common questions about DeepSeek-V4-Pro-0813 vs Grok-4.1 Fast Reasoning.