Lightfern for Email

Hey Product Hunt 👋

I’m Doug - I was OpenAI’s first hire in London but left to co-found Lightfern.

The problem:

AI-driven communication isn’t authentic.
You want to communicate clearly and thoughtfully. 

But wording your thoughts is time-consuming.

Lightfern is the telepathic AI writing tool. We started with a simple idea: Cursor, but for email. Today, we’re rolling out public availability for Gmail users via our browser extension.

• Finish thoughts before fingers hit keys. Lightfern nails the details that make emails feel like you - nicknames, sign-offs, your usual tone - and pulls context from past threads to finish your sentences the way you would.

• Build stronger relationships. Lightfern keeps you thoughtful, whether it’s remembering your VC’s ski trip to Switzerland or a long-forgotten invoice number.

• Redraft and edit without ever leaving the page. Chat with AI that already has full context.

All this with zero data retention by default.

Lightfern is the best autocomplete model in the world. Nothing else comes close in contextual awareness or speed.

🪴 Install now for unlimited free access during our beta: https://lightfern.com/.

We’ll be here all day to answer your questions and hear your thoughts, so please reach out and say hi :)

Lightfern for Email is probably the closest you're going to get to telepathy until Neuralink is out and available for general purpose use cases.

Therefore — until then, you really have to try Lightfern to get it.

Simply install the Chrome Extension, grant access to Gmail and Calendar (your data stays local unless you agree to cloud processing), and then go compose an email in Gmail or Outlook on the web and be amazed.

Here's what I love about this: the QWERTY keyboard was designed to slow down MECHANICAL TYPISTS.

We're still suffering from that design — when we could shorten the distance between what we intend to communicate and what actually ends up on the screen.

And that's what Lightfern is all about: helping you express yourself authentically — telepathically! — so you can get across what you really mean with integrity and clarity.

I've been using lightfern since it launched in beta. Doug, Matt and Marcus, its impressive what you've built. This is truly the closest to telepathy I've experienced. I love that it lives within gmail and doesn't add any noise to my tool stack. Its been a true productivity boost and makes replying to emails addictive 🚀

Hey all,

I'm Matt, one of the co-founders of Lightfern

I spent years as a researcher in medtech, so privacy has always been at the heart of what I build. One of the reasons we have a zero data retention policy as default. Developing this model was technically challenging and super fun for me so I hope you like it!

We built Lightfern because we were tired of AI writing tools that are optimised for the mean. Lightfern actually learns your style - how you write, your rhythm, the way you talk.

Try it and let us know what you think!

I have been using it since early private beta. I tried any sort of email automation to auto draft, nothing truly saved me time like Lightfern. I love that it knows my style, but also gives me control to edit and rephrase.

Hello! Marcus here, co-founder at Lightfern.

Super excited to hear any and all feedback from everyone! We’re all very keen to build a product for you.

Happy to answer any questions on the technical aspects of Lightfern too. I love a good discussion!

Over the moon to have worked on this! As a former journalist, the power of high-quality, expressive writing cannot be understated.

In the past, I've had to navigate writing my novel outside of my life and work in tech. I'm grateful to now combine my two worlds alongside such a talented technical team.

Can't wait to see what the future of communication looks like next!