TextCortex
An AI writing sidebar that follows you into Gmail and LinkedIn.
What is TextCortex?
TextCortex lives as a browser extension rather than a separate website, so it shows up as a small sidebar inside Gmail, LinkedIn, Notion, and pretty much anywhere else you type. Highlight text to rewrite it, or ask its assistant to draft something from scratch, without ever switching tabs to a chatbot. That everywhere-at-once approach is the whole pitch, at the cost of feeling less like a dedicated writing app.
TextCortex built its assistant, sometimes branded Zeno, around the idea that writing help should happen where the writing already happens, not in a separate browser tab you have to copy from. Since it works as an overlay across web apps, it ended up especially popular with sales and support teams replying to messages all day inside tools like LinkedIn and Gmail. The tradeoff for that convenience is that it feels more like a utility bolted onto other apps than a polished writing product in its own right.
Key features
- Sidebar/extension that works inside Gmail, LinkedIn, and most web apps
- Highlight-to-rewrite for tone, length, or clarity
- Chat assistant for drafting from scratch
- Custom brand voice and personas
- Templates for emails, replies, and social posts
- Chrome, Edge, and Word integrations
Pros
- Removes the tab-switching most AI writing tools require
- Genuinely handy for fast replies in email and LinkedIn
- Free tier lets you test it inside your actual workflow
Cons
- Feels more like a utility than a dedicated writing product
- Extension can conflict or lag inside some web apps
- Long-form writing is not where it is strongest
