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GPT-5.2 vs Grok-4 Heavy

GPT-5.2 and Grok-4 Heavy are closely matched at 41.4 and 40.7 on the LLM Stats Score.

OpenAI · xAI · Updated for 2026

Which is better?

GPT-5.2 and Grok-4 Heavy are closely matched on the overall LLM Stats Score at 41.4 and 40.7.

In the 3 individual benchmarks reported for both models, Grok-4 Heavy 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 GPT-5.2

  • you want predictable pricing at $1.75/M input and $14.00/M output

Choose Grok-4 Heavy

  • you value its reported benchmark strengths — it wins 2 of 3 exact shared results

At a glance

The differences that matter most.

Core performance indexes
41.4
#54
40.7
#56
40.7
#52
39.0
#60
23.9
#77
17.7
#118
Cost, coverage & limits
Benchmark wins
1 of 3
2 of 3
Input price
$1.75 / M
— / M
Output price
$14.00 / M
— / M
Context window
400,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT-5.2
Grok-4 Heavy
37.8#29
41.5#6
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

24 reported for GPT-5.2 · 6 for Grok-4 Heavy

3 shared

GPT-5.2 outperforms in 1 benchmarks (GPQA), while Grok-4 Heavy is better at 1 benchmark (Humanity's Last Exam).

Both models are evenly matched across the benchmarks.

Tue Sep 22 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-5.2 specifies input context (400,000 tokens). Only GPT-5.2 specifies output context (128,000 tokens).

OpenAI
GPT-5.2
Input400,000 tokens
Output128,000 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Tue Sep 22 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-5.2 and Grok-4 Heavy support multimodal inputs.

They are both capable of processing various types of data, offering versatility in application.

GPT-5.2

Text
Images
Audio
Video

Grok-4 Heavy

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-5.2

Proprietary

Closed source

Grok-4 Heavy

Proprietary

Closed source

Release Timeline

When each model was launched

GPT-5.2 was released on 2025-12-11, while Grok-4 Heavy's release date is not specified.

We can confirm GPT-5.2's release timeline, but cannot make a direct age comparison without Grok-4 Heavy's release date.

GPT-5.2

Dec 11, 2025

9 months ago

Grok-4 Heavy

Knowledge Cutoff

When training data ends

GPT-5.2 has a knowledge cutoff of 2025-08-25, while Grok-4 Heavy has a cutoff of 2024-12-31.

GPT-5.2 has more recent training data (up to 2025-08-25), making it potentially better informed about events through that date compared to Grok-4 Heavy (2024-12-31).

GPT-5.2

Aug 2025

8 mo newer
Grok-4 Heavy

Dec 2024

Outputs Comparison

Notice missing or incorrect data?Start an Issue discussion

Judge for yourself.

Run your own prompts against GPT-5.2 and Grok-4 Heavy side-by-side, then vote on the output you prefer.

GPT-5.2
✓ Preferred
Grok-4 Heavy
Open in Playground

FAQ

Common questions about GPT-5.2 vs Grok-4 Heavy.

Which is better, GPT-5.2 or Grok-4 Heavy?

GPT-5.2 and Grok-4 Heavy are closely matched on the LLM Stats Score at 41.4 and 40.7. GPT-5.2 is made by OpenAI and Grok-4 Heavy 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-5.2 compare to Grok-4 Heavy in benchmarks?

GPT-5.2 scores AIME 2025: 100.0%, HMMT 2025: 99.4%, Tau2 Telecom: 98.7%, Graphwalks BFS <128k: 94.0%, GPQA: 92.4%. Grok-4 Heavy scores AIME 2025: 100.0%, HMMT25: 96.7%, GPQA: 88.4%, LiveCodeBench: 79.4%, USAMO25: 61.9%.

What are the context window sizes for GPT-5.2 and Grok-4 Heavy?

GPT-5.2 supports 400K tokens and Grok-4 Heavy 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-5.2 and Grok-4 Heavy?

Key differences include LLM Stats Score (41.4 vs 40.7). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-5.2 and Grok-4 Heavy?

GPT-5.2 is developed by OpenAI and Grok-4 Heavy is developed by xAI.