GPT-5 mini vs Grok-4.1 Fast Reasoning
Comparing GPT-5 mini and Grok-4.1 Fast Reasoning across benchmarks, pricing, and capabilities.
OpenAI · xAI · Updated for 2026
Which is better?
GPT-5 mini 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 2.5x 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 LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.
Choose GPT-5 mini
- you want predictable pricing at $0.25/M input and $2.00/M output
Choose Grok-4.1 Fast Reasoning
- cost matters — it's about 2.5x cheaper per token
- you process long inputs — it offers a 2,000,000 token context window
- you want the most recent training data — it shipped Nov 2025
At a glance
The differences that matter most.
Individual benchmarks
5 reported for GPT-5 mini · 0 for Grok-4.1 Fast Reasoning
GPT-5 mini and Grok-4.1 Fast Reasoningdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.
Human preference
Blind head-to-head votes and playground preference scores
Pricing Analysis
Price comparison per million tokens
For input processing, GPT-5 mini ($0.25/1M tokens) is 1.3x more expensive than Grok-4.1 Fast Reasoning ($0.20/1M tokens).
For output processing, GPT-5 mini ($2.00/1M tokens) is 4.0x more expensive than Grok-4.1 Fast Reasoning ($0.50/1M tokens).
In conclusion, GPT-5 mini 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 GPT-5 mini's 400,000 tokens. GPT-5 mini can generate longer responses up to 128,000 tokens, while Grok-4.1 Fast Reasoning is limited to 30,000 tokens.
Input capabilities
Documented input modalities across available providers
Both GPT-5 mini and Grok-4.1 Fast Reasoning support multimodal inputs.
They are both capable of processing various types of data, offering versatility in application.
GPT-5 mini
Grok-4.1 Fast Reasoning
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-5 mini was released on 2025-08-07, while Grok-4.1 Fast Reasoning was released on 2025-11-17.
Grok-4.1 Fast Reasoning is 3 months newer than GPT-5 mini.
Aug 7, 2025
1.1 years ago
Nov 17, 2025
10 months ago
3mo newerKnowledge Cutoff
When training data ends
GPT-5 mini has a documented knowledge cutoff of 2024-05-30, while Grok-4.1 Fast Reasoning's cutoff date is not specified.
We can confirm GPT-5 mini's training data extends to 2024-05-30, but cannot make a direct comparison without Grok-4.1 Fast Reasoning's cutoff date.
May 2024
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Provider Availability
GPT-5 mini is available from OpenAI. Grok-4.1 Fast Reasoning is available from xAI.
GPT-5 mini
Grok-4.1 Fast Reasoning
Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-5 mini and Grok-4.1 Fast Reasoning side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-5 mini vs Grok-4.1 Fast Reasoning.