GPT-6 Astra vs Grok-1.5
GPT-6 Astra leads the LLM Stats Score 58.5 to -2.7.
OpenAI · xAI · Updated for 2026
Which is better?
GPT-6 Astra leads the overall LLM Stats Score 58.5 to -2.7, ranking #3 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 58.5 and ranks #3 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
- you want the most recent training data — it shipped Sep 2026
Choose Grok-1.5
- you are already invested in the xAI ecosystem
At a glance
The differences that matter most.
Capability indexes
Additional strengths measured across groups of related public benchmarks
Individual benchmarks
22 reported for GPT-6 Astra · 9 for Grok-1.5
GPT-6 Astra outperforms in 1 benchmarks (GPQA), while Grok-1.5 is better at 0 benchmarks.
GPT-6 Astra significantly outperforms across most benchmarks.
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).
Input capabilities
Documented input modalities across available providers
GPT-6 Astra supports multimodal inputs, whereas Grok-1.5 does not.
GPT-6 Astra can handle both text and other forms of data like images, making it suitable for multimodal applications.
GPT-6 Astra
Grok-1.5
License
Usage and distribution terms
Both models are licensed under proprietary licenses.
Both models have usage restrictions defined by their respective organizations.
Proprietary
Closed source
Proprietary
Closed source
Release Timeline
When each model was launched
GPT-6 Astra was released on 2026-09-04, while Grok-1.5 was released on 2024-03-28.
GPT-6 Astra is 30 months newer than Grok-1.5.
Sep 4, 2026
1 months ago
2.4yr newerMar 28, 2024
2.5 years ago
Knowledge Cutoff
When training data ends
GPT-6 Astra has a documented knowledge cutoff of 2026-04-30, while Grok-1.5's cutoff date is not specified.
We can confirm GPT-6 Astra's training data extends to 2026-04-30, but cannot make a direct comparison without Grok-1.5's cutoff date.
Apr 2026
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Outputs Comparison
Judge for yourself.
Run your own prompts against GPT-6 Astra and Grok-1.5 side-by-side, then vote on the output you prefer.
FAQ
Common questions about GPT-6 Astra vs Grok-1.5.