Release Notes

GPT-5 Now Live for Assistant Q&A

Harvey Assistant just got smarter—GPT-5 is now the default model for all chat and draft responses, bringing major upgrades in reasoning, reliability, and writing quality.

Release Date
Oct 6, 2025
Tier
Tier 3
Categories
Model Updates
Availability
US, EU

What's New

We’re excited to announce that GPT-5 is now powering Harvey Assistant for chat style conversations. GPT-5 delivers a significant leap forward in intelligence, transparency, and output quality, helping you generate more accurate, well-structured, and natural responses.

  • Transparent reasoning: GPT-5 now shows its “thinking” as it works, improving visibility and reducing perceived latency.
  • More intelligence: Performs ~11% better than GPT-4.1 on Big Law Bench.
  • Reduced hallucinations: Resolves numerous failure cases observed with GPT-4.1, offering more accurate and reliable outputs.
  • Fixed table formatting: GPT-5 consistently produces valid markdown tables—resolving 100% of past GPT-4.1 table formatting issues in internal testing.
  • Improved long-form writing: Generates fluent paragraphs instead of unwanted bullet points when longer narrative answers are requested.

Why it Matters

GPT-5 delivers sharper reasoning, clearer transparency, and higher-quality written outputs, empowering teams to produce better work faster and with greater confidence in accuracy.

How to Use

  • Chat: Simply open any thread in Harvey Assistant and start a conversation—GPT-5 is now the default model for all chats.
  • Draft: GPT-5 became the default for draft conversations in September, automatically ensuring improved structure and formatting.
  • For more information on our models and FAQs, visit What AI Models Does Harvey Use?

Limitations

Availability: GPT-5 is now live for all Harvey Assistant users except those in Australia, where GPT-5 processing capabilities are still being developed. Access for AU customers will follow soon.

GPT-5 Now Live for Assistant Q&A