Model Comparison

DeepSeek-V3.1 vs Grok-4.1 Fast Reasoning

Comparing DeepSeek-V3.1 and Grok-4.1 Fast Reasoning across benchmarks, pricing, and capabilities.

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Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

DeepSeek-V3.1 and Grok-4.1 Fast Reasoning don't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Pricing Analysis

Price comparison per million tokens

Grok-4.1 Fast Reasoning costs less

For input processing, DeepSeek-V3.1 ($0.27/1M tokens) is 1.4x more expensive than Grok-4.1 Fast Reasoning ($0.20/1M tokens).

For output processing, DeepSeek-V3.1 ($1.00/1M tokens) is 2.0x more expensive than Grok-4.1 Fast Reasoning ($0.50/1M tokens).

In conclusion, DeepSeek-V3.1 is more expensive than Grok-4.1 Fast Reasoning.*

* Using a 3:1 ratio of input to output tokens

Lowest available price from all providers
Fri Apr 17 2026 • llm-stats.com
DeepSeek
DeepSeek-V3.1
Input tokens$0.27
Output tokens$1.00
Best providerDeepinfra
xAI
Grok-4.1 Fast Reasoning
Input tokens$0.20
Output tokens$0.50
Best providerxAI
Notice missing or incorrect data?Start an Issue→

Context Window

Maximum input and output token capacity

Grok-4.1 Fast Reasoning accepts 2,000,000 input tokens compared to DeepSeek-V3.1's 163,840 tokens. DeepSeek-V3.1 can generate longer responses up to 163,840 tokens, while Grok-4.1 Fast Reasoning is limited to 30,000 tokens.

DeepSeek
DeepSeek-V3.1
Input163,840 tokens
Output163,840 tokens
xAI
Grok-4.1 Fast Reasoning
Input2,000,000 tokens
Output30,000 tokens
Fri Apr 17 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Grok-4.1 Fast Reasoning supports multimodal inputs, whereas DeepSeek-V3.1 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-V3.1

Text
Images
Audio
Video

Grok-4.1 Fast Reasoning

Text
Images
Audio
Video

License

Usage and distribution terms

DeepSeek-V3.1 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.

DeepSeek-V3.1

MIT

Open weights

Grok-4.1 Fast Reasoning

Proprietary

Closed source

Release Timeline

When each model was launched

DeepSeek-V3.1 was released on 2025-01-10, while Grok-4.1 Fast Reasoning was released on 2025-11-17.

Grok-4.1 Fast Reasoning is 10 months newer than DeepSeek-V3.1.

DeepSeek-V3.1

Jan 10, 2025

1.3 years ago

Grok-4.1 Fast Reasoning

Nov 17, 2025

5 months ago

10mo newer

Knowledge Cutoff

When training data ends

Neither model specifies a knowledge cutoff date.

Unable to compare the recency of their training data.

No cutoff dates available

Provider Availability

DeepSeek-V3.1 is available from DeepInfra, Novita. Grok-4.1 Fast Reasoning is available from xAI.

DeepSeek-V3.1

deepinfra logo
Deepinfra
Input Price:Input: $0.27/1MOutput Price:Output: $1.00/1M
novita logo
Novita
Input Price:Input: $0.27/1MOutput Price:Output: $1.00/1M

Grok-4.1 Fast Reasoning

xai logo
xAI
Input Price:Input: $0.20/1MOutput Price:Output: $0.50/1M
* Prices shown are per million tokens

Outputs Comparison

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Key Takeaways

DeepSeek
Has open weights
xAI
Larger context window (2,000,000 tokens)
Supports multimodal inputs
Less expensive input tokens
Less expensive output tokens

Detailed Comparison

AI Model Comparison Table
Feature
DeepSeek
DeepSeek-V3.1
xAI
Grok-4.1 Fast Reasoning

FAQ

Common questions about DeepSeek-V3.1 vs Grok-4.1 Fast Reasoning

DeepSeek-V3.1 (DeepSeek) and Grok-4.1 Fast Reasoning (xAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.
DeepSeek-V3.1 scores SimpleQA: 93.4%, MMLU-Redux: 91.8%, MMLU-Pro: 83.7%, GPQA: 74.9%, CodeForces: 69.7%.
Grok-4.1 Fast Reasoning is 1.4x cheaper for input tokens. DeepSeek-V3.1 costs $0.27/M input and $1.00/M output via deepinfra. Grok-4.1 Fast Reasoning costs $0.20/M input and $0.50/M output via xai.
DeepSeek-V3.1 supports 164K tokens and Grok-4.1 Fast Reasoning supports 2.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.
Key differences include context window (164K vs 2.0M), input pricing ($0.27 vs $0.20/M), multimodal support (no vs yes), licensing (MIT vs Proprietary). See the full comparison above for benchmark-by-benchmark results.
DeepSeek-V3.1 is developed by DeepSeek and Grok-4.1 Fast Reasoning is developed by xAI.