Lightfern is an AI-powered email tool that provides blazing fast autocomplete functionality designed to write in your personal style. It works directly within your inbox as a browser extension, helping users complete emails more efficiently while maintaining their unique voice and tone.

Lightfern nails greetings, signoffs, nicknames, and tone—everything that makes your voice yours. It remembers details like your VC's ski trip to Switzerland or long-forgotten invoice numbers to help build stronger relationships. The tool offers redrafting and editing capabilities without requiring users to leave the page, seeing what you see so you can edit without copying and pasting across tabs and LLMs.

Lightfern uses Ultracomplete, which it describes as the world's best autocomplete model in terms of context awareness and speed. The technology pulls context from past email threads to finish sentences the way you would, working directly in your inbox with zero configuration required.

The product helps users finish thoughts before fingers hit keys, keeping communications thoughtful and personalized. It enables professionals to maintain their authentic voice while saving time on email composition and editing tasks.

Lightfern is trusted by professionals including investors and GTM specialists, and it features zero data retention by default unless users explicitly opt in. The browser extension-based tool requires no fuss setup—users simply install the extension and connect their email.