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Grok-1.5 vs o4-mini

o4-mini significantly outperforms across most benchmarks.

xAI · OpenAI · Updated for 2026

Which is better?

Grok-1.5 outperforms in 0 benchmarks, while o4-mini is better at 3 benchmarks (GPQA, MathVista, MMMU). o4-mini significantly outperforms across most benchmarks.

Based on current benchmark, pricing, and model metadata for 2026.

Choose Grok-1.5

  • you are already invested in the xAI ecosystem

Choose o4-mini

  • you want the strongest raw capability — it leads on 3 of 3 shared benchmarks
  • you want the most recent training data — it shipped Apr 2025

At a glance

The differences that matter most.

Grok-1.5
xAI
o4-mini
OpenAI
Benchmark wins
0 of 3
3 of 3
Input price
— / M
$1.10 / M
Output price
— / M
$4.40 / M
Context window
—
200,000
Released
Mar 2024
Apr 2025
License
Proprietary
Proprietary

Performance Benchmarks

Comparative analysis across standard metrics

3 benchmarks

Grok-1.5 outperforms in 0 benchmarks, while o4-mini is better at 3 benchmarks (GPQA, MathVista, MMMU).

o4-mini significantly outperforms across most benchmarks.

Mon Aug 24 2026 • llm-stats.com

Arena Performance

Playground indexes and blind preference scores

Context Window

Maximum input and output token capacity

Only o4-mini specifies input context (200,000 tokens). Only o4-mini specifies output context (100,000 tokens).

xAI
Grok-1.5
Input- tokens
Output- tokens
OpenAI
o4-mini
Input200,000 tokens
Output100,000 tokens
Mon Aug 24 2026 • llm-stats.com

Input Capabilities

Supported data types and modalities

o4-mini supports multimodal inputs, whereas Grok-1.5 does not.

o4-mini can handle both text and other forms of data like images, making it suitable for multimodal applications.

Grok-1.5

Text
Images
Audio
Video

o4-mini

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

o4-mini

Proprietary

Closed source

Release Timeline

When each model was launched

Grok-1.5 was released on 2024-03-28, while o4-mini was released on 2025-04-16.

o4-mini is 13 months newer than Grok-1.5.

Grok-1.5

Mar 28, 2024

2.4 years ago

o4-mini

Apr 16, 2025

1.4 years ago

1.1yr newer

Knowledge Cutoff

When training data ends

o4-mini has a documented knowledge cutoff of 2024-05-31, while Grok-1.5's cutoff date is not specified.

We can confirm o4-mini's training data extends to 2024-05-31, but cannot make a direct comparison without Grok-1.5's cutoff date.

Grok-1.5

—

o4-mini

May 2024

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Grok-1.5 and o4-mini side-by-side, then vote on the output you prefer.

Grok-1.5
✓ Preferred
o4-mini
Open in Playground

FAQ

Common questions about Grok-1.5 vs o4-mini.

Which is better, Grok-1.5 or o4-mini?

o4-mini significantly outperforms across most benchmarks. Grok-1.5 is made by xAI and o4-mini is made by OpenAI. The best choice depends on your use case — compare their benchmark scores, pricing, and capabilities above.

How does Grok-1.5 compare to o4-mini in benchmarks?

Grok-1.5 scores GSM8k: 90.0%, DocVQA: 85.6%, MMLU: 81.3%, HumanEval: 74.1%, MMMU: 53.6%. o4-mini scores AIME 2024: 93.4%, AIME 2025: 92.7%, MathVista: 84.3%, MMMU: 81.6%, GPQA: 81.4%.

What are the context window sizes for Grok-1.5 and o4-mini?

Grok-1.5 supports an unknown number of tokens and o4-mini supports 200K 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 o4-mini?

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

Who makes Grok-1.5 and o4-mini?

Grok-1.5 is developed by xAI and o4-mini is developed by OpenAI.

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