GPT-5.4 Now Available in Harvey

Harvey has integrated OpenAI's latest frontier model, GPT-5.4, into its legal AI platform. The new model builds on the strengths of GPT-5.2 while delivering meaningful improvements across key dimensions that matter for legal work: substantive accuracy, drafting precision, and organizational clarity.

Performance Improvements

On Harvey's BigLaw Bench evaluation suite—a comprehensive legal task benchmark—GPT-5.4 achieved a score of 91.0%, up from GPT-5.2's 89.8%. The model earned perfect scores on risk assessment and compliance tasks, with particularly strong performance in deal management, drafting, and litigation filing analysis. These improvements translate to practical benefits for legal practitioners handling detail-intensive transactional and advisory work.

Key Strengths

According to Harvey's Applied Legal Research team, GPT-5.4 demonstrates several notable capabilities:

• Efficiency: Fast and comprehensive processing with strong underlying substance
• Clarity: Gets directly to the task at hand without preamble or unnecessary throat-clearing
• Organization: Intuitive structure with appropriate levels of detail
• Drafting: Improved format and organizational structure suitable for professional legal documents

Availability

GPT-5.4 will be rolled out in the model selector for eligible clients in the US and EU in the coming days, with Australia availability to follow as in-region capacity permits.