GPT-6 Astra vs Hy4 preview: Specs & Benchmark Comparison

GPT-6 Astra is developed by OpenAI, while Hy4 preview comes from Tencent. Hy4 preview was released in August 2026, and GPT-6 Astra followed a month later in September 2026. Hy4 preview has a published size of about 770 billion parameters; OpenAI has not disclosed the parameter count of GPT-6 Astra.

The two models share 4 published benchmarks. GPT-6 Astra leads on 4 of them. The widest gaps are on Agents' Last Exam, where GPT-6 Astra scores 59.3% against 22.8%; AutomationBench, where GPT-6 Astra scores 41.4% against 32.1%. Averaged across everything we track, GPT-6 Astra sits at 74.4% and Hy4 preview at 58.7%.

GPT-6 Astra is available through an API at $10 per million input tokens with a 1M-token context window. We do not track a hosted API for Hy4 preview, so pricing and context cannot be compared directly.

CharacteristicGPT-6 AstraHy4 preview
CompanyOpenAITencent
Release DateSeptember 4, 2026August 28, 2026
Parameters—770B
MultimodalYesNo
Context (input)1.1M—
Context (output)128K—
Input Price / 1M$10.00—
Output Price / 1M$50.00—
Average Score74.4%58.7%
Benchmarks
Agents' Last Exam59.3%22.8%
AutomationBench41.4%32.1%
GPQA Diamond96.0%92.3%
Humanity's Last Exam (with tools, text-only)57.2%55.4%

Visual Benchmark Comparison

GPT-6 Astra
Hy4 preview
Agents' Last Exam0.6 vs 0.2
0.6
0.2
AutomationBench0.4 vs 0.3
0.4
0.3
GPQA Diamond1.0 vs 0.9
1.0
0.9
Humanity's Last Exam (with tools, text-only)0.6 vs 0.6
0.6
0.6

Verdict

Both models show equal results — the choice depends on your specific use case.

Overall Performance

Both models show comparable average scores: GPT-6 Astra — 0.7, Hy4 preview — 0.6.

Recency

Both models were released around the same time: 9/4/2026 and 8/28/2026.

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Frequently Asked Questions

Which is better for coding — GPT-6 Astra or Hy4 preview?
Direct comparison on the SWE-Bench benchmark is not available. We recommend reviewing other metrics on the comparison page.
Which model is cheaper — GPT-6 Astra or Hy4 preview?
API pricing data is available on the individual model pages.
Which has a larger context window — GPT-6 Astra or Hy4 preview?
Context window data is available on the individual model pages.

The GPT-6 Astra and Hy4 preview comparison is updated for 2026. Data includes benchmark results, API pricing, context window size and other specifications. For more detailed information, visit the GPT-6 Astra or Hy4 preview page. See also the complete list of AI model comparisons.