Text Expander with AI — AI Commands in Every Desktop App

Traditional text expanders retrieve fixed snippets. Lightning Assist goes further: it combines snippet expansion with built-in AI commands that rewrite, enhance, translate, summarize, and generate text directly in the app where you are working. No browser tab switching, no copy-pasting into ChatGPT.

AI Chat, AI Commands, AI Enhance and push-to-talk voice work on the free plan. AI features use AI Credits and voice uses Speech credits, not a subscription — every account starts with some of each.

Nothing you build on the free plan is ever locked or deleted. If you ever try Pro and stop, every snippet you own keeps expanding.

Short Answer

An AI text expander combines classic snippet expansion with on-demand AI. Lightning Assist expands your saved snippets as you type in any desktop app, its AI Commands rewrite, translate or summarize the text you select, and push-to-talk dictation turns your speech into text — on Windows, macOS, and Linux, with a 14-day free trial and no credit card.

Start with a 14-Day Pro Trial

Free: create up to 20 snippets, with unlimited expansion. AI and voice use credits. No credit card required.

Download Lightning Assist

Part of the AI writing assistant — the cross-platform productivity app for Windows, macOS, and Linux.

Static Snippets + Dynamic AI — Both in One Tool

Lightning Assist handles two kinds of text expansion:

Static Snippets

Type a shortcut such as ;sig and your saved snippet replaces it as you type — or press your hotkey, if you prefer Hotkey mode. Perfect for email signatures, canned replies, code templates, standard phrases, and anything you type repeatedly word-for-word.

AI Commands

Select text in any application, then press the AI Enhance shortcut and type an instruction or pick a quick action (Improve writing, Fix grammar & spelling, Translate, Make shorter, Summarize), or press the shortcut of one of your saved commands. Check the answer and paste it back. No browser, no copy-paste.

AI Commands You Can Use Right Now

Rewrite & Improve

Select a rough draft, press the shortcut, and get a clearer version with the same meaning — in your email client, Slack, or wherever you wrote it.

Adjust Tone

Save an instruction such as 'make this more formal' or 'make it friendlier' as a command with its own shortcut, and run it on any text you select.

Translate

Translate selected text into one of over 40 languages, or type another one, directly in the active application.

Summarise

Condense long text to its main points in a few sentences, or save a command that turns it into bullet points — useful for meeting notes, articles, or long messages.

Generate from Prompt

Select a few notes or a question and run an instruction like 'draft a reply from these notes': the AI writes from what you selected. AI Commands always start from a selection.

Custom Commands

Create up to 50 commands with your own instructions, each with its own shortcut, the model you want (Standard or Best quality), and the choice to review the answer first or paste it right away.

Why Not Just Use ChatGPT?

ChatGPT is powerful but slow for everyday writing tasks. The workflow is:

Switch to browser tab
Open ChatGPT
Paste your text
Describe what you want
Wait for response
Copy the result
Switch back, paste

Lightning Assist AI Commands: select text, press a shortcut, check the answer, press Submit. A saved command set to run immediately skips the check and pastes the answer. Same result, a fraction of the friction, in any application.

Works in Every Desktop App

Lightning Assist is a native desktop app. AI commands work in:

Email clients — Outlook, Thunderbird, Apple Mail, Gmail in browser
Code editors — VS Code, JetBrains IDEs, Sublime Text
Chat & messaging — Slack, Teams, Discord, Telegram desktop
Documents — Word, Google Docs, Notion, Confluence
CRM & support tools — HubSpot, Salesforce, Zendesk, Intercom
Terminals on Windows and macOS — in Linux terminals Ctrl+C stops the running program instead of copying

Start Using AI Commands Today

Start on Free with a 14-day Pro trial, no card required. AI and voice use credits. After the trial, continue on Free; your existing snippets keep working.

Download Lightning Assist See AI Features

Frequently Asked Questions

What is an AI text expander?

An AI text expander combines traditional text expansion (typing a short shortcut that expands into a full snippet) with AI-powered commands that can generate, rewrite, enhance, or translate text on the fly. Instead of only retrieving static saved snippets, an AI text expander can adapt, improve, and create content dynamically based on context.

How does AI text expansion work in Lightning Assist?

Lightning Assist does two things. Snippets type the same saved text every time you use their shortcut. AI Commands work on text you select: press the AI Enhance shortcut and give an instruction, or press the shortcut of a saved command; you check the answer and paste it back, or let a saved command paste it on its own.

Does the AI work across your applications?

Yes, wherever you can select text and copy it with Ctrl+C (Cmd+C on a Mac): your email client, word processor, code editor, chat apps and browser. Linux terminals are the exception, because there Ctrl+C stops the running program. There is no copy-pasting into a web interface.

What AI commands are available?

AI Enhance has quick actions for improving writing, fixing grammar and spelling, translating, making text shorter and summarizing, and you can type any other instruction. You can also save up to 50 commands of your own, each with its own shortcut.

Is Lightning Assist only an AI tool, or does it also do traditional text expansion?

Both. Lightning Assist is first and foremost a text expander — you can have hundreds of static snippets triggered by shortcuts. AI is an additional layer on top. Many users use snippets for fixed, frequently repeated text and AI commands for situations where the output needs to vary or be improved.

How does it compare to using ChatGPT for text editing?

ChatGPT requires you to switch to a browser tab, paste your text, describe what you want, copy the result, and paste it back. Lightning Assist AI commands do the job in place — select text in any app, press a hotkey, and the result appears where your cursor is. Static snippets handle the parts that never change; AI commands handle the parts that need context.

Do the AI features cost extra?

They run on credits, on every plan. New accounts get 200 AI Credits and 200 Speech Credits; a paid Pro plan adds 1000 of each every month, and packs can be bought when you need more. The cost of an AI Command depends on the text and the model: rewriting a 100-word email takes about 2 credits on Standard and about 40 on Best quality.

Can I save my ChatGPT prompts as snippets?

Yes. A snippet can hold a prompt, and Lightning Assist types it into ChatGPT, Claude or any other chat box when you use its shortcut. That uses no AI Credits, because the chat service runs the prompt. AI Commands are different: Lightning Assist runs the AI itself on the text you select.