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GPT-6 Astra vs Grok-4 Heavy

GPT-6 Astra leads the LLM Stats Score 60.7 to 40.9.

OpenAI · xAI · Updated for 2026

Which is better?

GPT-6 Astra leads the overall LLM Stats Score 60.7 to 40.9, ranking #1 overall.

In the 1 individual benchmarks reported for both models, GPT-6 Astra wins 1; 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-6 Astra

  • overall performance matters — it scores 60.7 and ranks #1 on LLM Stats
  • your work emphasizes reasoning and coding — it leads those capability indexes
  • you value its reported benchmark strengths — it wins 1 of 1 exact shared results

Choose Grok-4 Heavy

  • you are already invested in the xAI ecosystem

At a glance

The differences that matter most.

Core performance indexes
60.7
#1
40.9
#50
58.7
#1
39.2
#53
49.0
#1
17.9
#108
Cost, coverage & limits
Benchmark wins
1 of 1
0 of 1
Input price
$10.00 / M
— / M
Output price
$50.00 / M
— / M
Context window
1,050,000

Capability indexes

Additional strengths measured across groups of related public benchmarks

1 shared
Index
GPT-6 Astra
Grok-4 Heavy
35.3#42
41.4#6
Conservative TrueSkill rating · higher is betterHow scores work

Individual benchmarks

22 reported for GPT-6 Astra · 6 for Grok-4 Heavy

1 shared

GPT-6 Astra outperforms in 1 benchmarks (GPQA), while Grok-4 Heavy is better at 0 benchmarks.

GPT-6 Astra significantly outperforms across most benchmarks.

Fri Sep 04 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-6 Astra specifies input context (1,050,000 tokens). Only GPT-6 Astra specifies output context (128,000 tokens).

OpenAI
GPT-6 Astra
Input1,050,000 tokens
Output128,000 tokens
xAI
Grok-4 Heavy
Input- tokens
Output- tokens
Fri Sep 04 2026 • llm-stats.com

Input capabilities

Documented input modalities across available providers

Both GPT-6 Astra and Grok-4 Heavy support multimodal inputs.

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

GPT-6 Astra

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-6 Astra

Proprietary

Closed source

Grok-4 Heavy

Proprietary

Closed source

Release Timeline

When each model was launched

Neither model specifies a release date.

Unable to compare the release dates of the models.

No release dates available

Knowledge Cutoff

When training data ends

GPT-6 Astra has a knowledge cutoff of 2026-04-30, while Grok-4 Heavy has a cutoff of 2024-12-31.

GPT-6 Astra has more recent training data (up to 2026-04-30), making it potentially better informed about events through that date compared to Grok-4 Heavy (2024-12-31).

GPT-6 Astra

Apr 2026

1.3 yr 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-6 Astra and Grok-4 Heavy side-by-side, then vote on the output you prefer.

GPT-6 Astra
✓ Preferred
Grok-4 Heavy
Open in Playground

FAQ

Common questions about GPT-6 Astra vs Grok-4 Heavy.

Which is better, GPT-6 Astra or Grok-4 Heavy?

GPT-6 Astra leads the LLM Stats Score 60.7 to 40.9. GPT-6 Astra 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-6 Astra compare to Grok-4 Heavy in benchmarks?

GPT-6 Astra scores ExploitBench: 100.0%, ARC-AGI-3: 99.9%, ARC-AGI: 98.5%, FrontierMath Tier 4 (v2): 97.6%, GPQA: 96.0%. 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-6 Astra and Grok-4 Heavy?

GPT-6 Astra supports 1.1M 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-6 Astra and Grok-4 Heavy?

Key differences include LLM Stats Score (60.7 vs 40.9). See the full comparison above for benchmark-by-benchmark results.

Who makes GPT-6 Astra and Grok-4 Heavy?

GPT-6 Astra is developed by OpenAI and Grok-4 Heavy is developed by xAI.