Harvey announces GPT-6 models for legal work

Harvey said on 2026-09-03 that GPT-6 Astra would soon be available to its customers, and later said GPT-6 Sol, GPT-6 Luna and GPT-6.1 Sol were also coming soon to the platform. Kevin O'Keefe reported on 2026-09-18 that OpenAI had released Astra for Law, a GPT-6 model tailored for legal work.

Harvey said its early testing of GPT-6 Astra showed substantial quality improvements over GPT-5.6 Sol in capital markets, corporate M&A and data privacy. It said GPT-6 Sol showed particular strength on tax, immigration, healthcare and life sciences, with additional gains in insurance and funds and asset management over 5.6 Sol. Harvey said GPT-6.1 Sol performed best on transactional and capital markets work, including corporate M&A and emerging companies and venture capital, while maintaining similar legal accuracy at lower reasoning levels.

Legora said on 2026-09-23 that it had tested GPT-6 Sol and GPT-6 Luna against the Legora BAR. The company said GPT-6 Sol caught substantive contract changes that other models missed and applied the strict evidence standard that audit preparation demands, while GPT-6 Luna exceeded the baseline at carrying the sentence that was cut off in the post.