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GPT-4o vs Grok-1.5

GPT-4o leads the LLM Stats Score 14.6 to -2.0.

OpenAI · xAI · Updated for 2026

Which is better?

GPT-4o leads the overall LLM Stats Score 14.6 to -2.0, ranking #215 overall.

In the 6 individual benchmarks reported for both models, GPT-4o wins 6; 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 GPT-4o

  • overall performance matters — it scores 14.6 and ranks #215 on LLM Stats
  • your work emphasizes reasoning — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 6 of 6 exact shared results
  • you want the most recent training data — it shipped Aug 2024

Choose Grok-1.5

  • you are already invested in the xAI ecosystem

At a glance

The differences that matter most.

Core performance indexes
14.6
#215
-2.0
#317
16.3
#199
-1.5
#309
-0.2
#225
-0.8
#228
Cost, coverage & limits
Benchmark wins
6 of 6
0 of 6
Input price
$2.50 / M
— / M
Output price
$10.00 / M
— / M
Context window
128,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

5 shared
Index
GPT-4o
Grok-1.5
12.7#218
5.5#259
9.1#124
-4.7#192
12.7#98
-2.2#151
16.2#108
5.3#159
16.2#91
5.3#144
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

38 reported for GPT-4o · 9 for Grok-1.5

6 shared

GPT-4o outperforms in 6 benchmarks (DocVQA, GPQA, MathVista, MMLU, MMLU-Pro, MMMU), while Grok-1.5 is better at 0 benchmarks.

GPT-4o significantly outperforms across most benchmarks.

Sun Aug 30 2026 • llm-stats.com

Human preference

Blind head-to-head votes and playground preference scores

Context Window

Maximum input and output token capacity

Only GPT-4o specifies input context (128,000 tokens). Only GPT-4o specifies output context (16,384 tokens).

OpenAI
GPT-4o
Input128,000 tokens
Output16,384 tokens
xAI
Grok-1.5
Input- tokens
Output- tokens
Sun Aug 30 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

GPT-4o supports multimodal inputs, whereas Grok-1.5 does not.

GPT-4o can handle both text and other forms of data like images, making it suitable for multimodal applications.

GPT-4o

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.

GPT-4o

Proprietary

Closed source

Grok-1.5

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-4o was released on 2024-08-06, while Grok-1.5 was released on 2024-03-28.

GPT-4o is 4 months newer than Grok-1.5.

GPT-4o

Aug 6, 2024

2.1 years ago

4mo newer
Grok-1.5

Mar 28, 2024

2.4 years ago

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

Judge for yourself.

Run your own prompts against GPT-4o and Grok-1.5 side-by-side, then vote on the output you prefer.

GPT-4o
✓ Preferred
Grok-1.5
Open in Playground

FAQ

Common questions about GPT-4o vs Grok-1.5.

Which is better, GPT-4o or Grok-1.5?

GPT-4o leads the LLM Stats Score 14.6 to -2.0. GPT-4o is made by OpenAI 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 GPT-4o compare to Grok-1.5 in benchmarks?

GPT-4o scores AI2D: 94.2%, DocVQA: 92.8%, ChartQA: 85.7%, MMLU: 85.7%, CharXiv-D: 85.3%. 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 GPT-4o and Grok-1.5?

GPT-4o supports 128K 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 GPT-4o and Grok-1.5?

Key differences include LLM Stats Score (14.6 vs -2.0), multimodal support (yes vs no). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-4o and Grok-1.5?

GPT-4o is developed by OpenAI and Grok-1.5 is developed by xAI.