The AI arena is free today

Open Superagent

Gemini 2.5 Pro vs Grok-1.5

Gemini 2.5 Pro leads the LLM Stats Score 27.8 to -2.6.

Google · xAI · Updated for 2026

Which is better?

Gemini 2.5 Pro leads the overall LLM Stats Score 27.8 to -2.6, ranking #137 overall.

In the 2 individual benchmarks reported for both models, Gemini 2.5 Pro wins 2; this is a narrower head-to-head signal than the composite indexes.

Based on current LLM Stats indexes, shared benchmarks, pricing, and model metadata for 2026.

Choose Gemini 2.5 Pro

  • overall performance matters — it scores 27.8 and ranks #137 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 2 of 2 exact shared results
  • you want the most recent training data — it shipped May 2025

Choose Grok-1.5

  • you are already invested in the xAI ecosystem

At a glance

The differences that matter most.

Gemini 2.5 Pro
Google
Grok-1.5
xAI
Core performance indexes
LLM Stats Score
27.8
#137
-2.6
#339
Reasoning
27.3
#137
-2.2
#329
Coding
12.8
#140
-0.9
#245
Cost, coverage & limits
Benchmark wins
2 of 2
0 of 2
Input price
$1.25 / M
— / M
Output price
$10.00 / M
— / M
Context window
1,000,000
—

Capability indexes

Additional strengths measured across groups of related public benchmarks

3 shared
Index
Gemini 2.5 Pro
Grok-1.5
Math
22.6#135
4.9#276
Vision
16.1#87
-5.2#201
Multimodal
22.4#60
-2.6#160
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

16 reported for Gemini 2.5 Pro · 9 for Grok-1.5

2 shared

Gemini 2.5 Pro outperforms in 2 benchmarks (GPQA, MMMU), while Grok-1.5 is better at 0 benchmarks.

Gemini 2.5 Pro significantly outperforms across most benchmarks.

Mon Sep 14 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only Gemini 2.5 Pro specifies input context (1,000,000 tokens). Only Gemini 2.5 Pro specifies output context (1,000,000 tokens).

Google
Gemini 2.5 Pro
Input1,000,000 tokens
Output1,000,000 tokens
xAI
Grok-1.5
Input- tokens
Output- tokens
Mon Sep 14 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Gemini 2.5 Pro supports multimodal inputs, whereas Grok-1.5 does not.

Gemini 2.5 Pro can handle both text and other forms of data like images, making it suitable for multimodal applications.

Gemini 2.5 Pro

Text
Images
Audio
Video

Grok-1.5

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.

Gemini 2.5 Pro

Proprietary

Closed source

Grok-1.5

Proprietary

Closed source

Release Timeline

When each model was launched

Gemini 2.5 Pro was released on 2025-05-20, while Grok-1.5 was released on 2024-03-28.

Gemini 2.5 Pro is 14 months newer than Grok-1.5.

Gemini 2.5 Pro

May 20, 2025

1.3 years ago

1.1yr newer
Grok-1.5

Mar 28, 2024

2.5 years ago

Knowledge Cutoff

When training data ends

Gemini 2.5 Pro has a documented knowledge cutoff of 2025-01-31, while Grok-1.5's cutoff date is not specified.

We can confirm Gemini 2.5 Pro's training data extends to 2025-01-31, but cannot make a direct comparison without Grok-1.5's cutoff date.

Gemini 2.5 Pro

Jan 2025

Grok-1.5

—

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion→

Judge for yourself.

Run your own prompts against Gemini 2.5 Pro and Grok-1.5 side-by-side, then vote on the output you prefer.

Gemini 2.5 Pro
✓ Preferred
Grok-1.5
Open in Playground

FAQ

Common questions about Gemini 2.5 Pro vs Grok-1.5.

Which is better, Gemini 2.5 Pro or Grok-1.5?

Gemini 2.5 Pro leads the LLM Stats Score 27.8 to -2.6. Gemini 2.5 Pro is made by Google and Grok-1.5 is made by xAI. The best choice depends on your use case — compare their capability indexes, individual benchmarks, pricing, and limits above.

How does Gemini 2.5 Pro compare to Grok-1.5 in benchmarks?

Gemini 2.5 Pro scores MRCR: 93.0%, AIME 2024: 92.0%, Global-MMLU-Lite: 88.6%, Video-MME: 84.8%, AIME 2025: 83.0%. 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 Gemini 2.5 Pro and Grok-1.5?

Gemini 2.5 Pro supports 1.0M tokens and Grok-1.5 supports an unknown number of tokens. A larger context window lets you process longer documents, conversations, or codebases in a single request.

What are the main differences between Gemini 2.5 Pro and Grok-1.5?

Key differences include LLM Stats Score (27.8 vs -2.6), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes Gemini 2.5 Pro and Grok-1.5?

Gemini 2.5 Pro is developed by Google and Grok-1.5 is developed by xAI.

Related comparisons