Model Comparison

Grok-1.5 vs Grok-4.1 Fast Non-ReasoningWhich is better in 2026?

Comparing Grok-1.5 and Grok-4.1 Fast Non-Reasoning across benchmarks, pricing, and capabilities.

Verdict: Grok-1.5 vs Grok-4.1 Fast Non-Reasoning — which is better?

Grok-1.5 (by xAI) and Grok-4.1 Fast Non-Reasoning (by xAI) 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.

Choose Grok-1.5 if…

  • you are already invested in the xAI ecosystem

Choose Grok-4.1 Fast Non-Reasoning if…

  • you want the most recent training data — it shipped Nov 2025

Performance Benchmarks

Comparative analysis across standard metrics

No common benchmarks found

Grok-1.5 and Grok-4.1 Fast Non-Reasoningdon't have any common benchmark datasets to compare. They may have been evaluated on different testing suites.

Arena Performance

Human preference votes

Context Window

Maximum input and output token capacity

Only Grok-4.1 Fast Non-Reasoning specifies input context (2,000,000 tokens). Only Grok-4.1 Fast Non-Reasoning specifies output context (30,000 tokens).

xAI
Grok-1.5
Input- tokens
Output- tokens
xAI
Grok-4.1 Fast Non-Reasoning
Input2,000,000 tokens
Output30,000 tokens
Wed Jul 15 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

Grok-4.1 Fast Non-Reasoning supports multimodal inputs, whereas Grok-1.5 does not.

Grok-4.1 Fast Non-Reasoning can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok-1.5

Text
Images
Audio
Video

Grok-4.1 Fast Non-Reasoning

Text
Images
Audio
Video

License

Usage and distribution terms

Both models are licensed under proprietary licenses.

Both models have usage restrictions defined by their respective organizations.

Grok-1.5

Proprietary

Closed source

Grok-4.1 Fast Non-Reasoning

Proprietary

Closed source

Release Timeline

When each model was launched

Grok-1.5 was released on 2024-03-28, while Grok-4.1 Fast Non-Reasoning was released on 2025-11-17.

Grok-4.1 Fast Non-Reasoning is 20 months newer than Grok-1.5.

Grok-1.5

Mar 28, 2024

2.3 years ago

Grok-4.1 Fast Non-Reasoning

Nov 17, 2025

8 months ago

1.6yr 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

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Key Takeaways

xAI

No standout differentiators in the data we have for this pair.

xAI
Larger context window (2,000,000 tokens)
Supports multimodal inputs

Detailed Comparison

Interactive Arena

Judge for yourself.

Run your own prompts against Grok-1.5 and Grok-4.1 Fast Non-Reasoning side-by-side, then vote on the output you prefer.

Grok-1.5
✓ Preferred
Grok-4.1 Fast Non-Reasoning
Open in Playground
AI Model Comparison Table
Feature
xAI
Grok-1.5
xAI
Grok-4.1 Fast Non-Reasoning

FAQ

Common questions about Grok-1.5 vs Grok-4.1 Fast Non-Reasoning.

Which is better, Grok-1.5 or Grok-4.1 Fast Non-Reasoning?

Grok-1.5 (xAI) and Grok-4.1 Fast Non-Reasoning (xAI) each have strengths in different areas. Compare their benchmark scores, pricing, context windows, and capabilities above to determine which fits your needs.

How does Grok-1.5 compare to Grok-4.1 Fast Non-Reasoning in benchmarks?

Grok-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%.

What are the context window sizes for Grok-1.5 and Grok-4.1 Fast Non-Reasoning?

Grok-1.5 supports an unknown number of tokens and Grok-4.1 Fast Non-Reasoning supports 2.0M tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Grok-1.5 and Grok-4.1 Fast Non-Reasoning?

Key differences include multimodal support (no vs yes). See the full comparison above for benchmark-by-benchmark results.

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