Turn the currently open Markdown or HTML file into a live local preview link you can open in a browser or copy and share, refreshing instantly as you edit.
Installation
Launch VS Code Quick Open (Ctrl+P), paste the following command, and press enter.
Turn the currently open Markdown or HTML file into a live local preview link: open it in a browser, or copy the link and share it with a colleague or another device. The browser content refreshes automatically as you edit — no need to manually refresh, and no need to save the file first.
Features
Supports both Markdown and HTML files
Run "OnAir: Generate Live Preview Link" from the Command Palette, right-click menu, or the editor title bar icon
A picker lets you choose Open in Browser or Copy Link to Clipboard, so you decide how to use the link
The link is stable: generating it again for the same file gives you the same address
Live sync: editing in VS Code (no need to save) triggers an automatic refresh; Markdown updates in place (no flash), while HTML does a full page reload since it's a complete page with its own styles/scripts
Markdown code blocks get syntax highlighting (highlight.js)
Multiple files can each have their own preview link running at the same time, independently
When a file is closed, the browser shows a "source file closed, preview will no longer update" notice
Usage
Open a .md or .html file
Open the Command Palette with Cmd+Shift+P and run OnAir: Generate Live Preview Link (or click the globe icon in the top-right of the editor)
Choose Open in Browser to launch it directly, or Copy Link to Clipboard to paste it elsewhere
Keep editing — the browser content updates automatically
How it works / Notes
When activated, the extension starts a local HTTP + WebSocket server, searching for an available port starting from 5757
Links look like http://127.0.0.1:<port>/preview/<id> and can only be opened in a browser on this machine — they are not public addresses. To share with someone else, you'd need to be on the same local network and replace 127.0.0.1 with your LAN IP, or set up your own tunnel (e.g. ngrok)
The local server stops when VS Code closes, so links naturally expire
TODO (optional future improvements)
[ ] Auto-detect LAN IP, to make sharing with colleagues on the same WiFi easier
