TVKit

A proxy server to use a modern dev server in old browsers. "Run SvelteKit on a TV"

TVKit intercepts requests to the other webserver and makes them work in old browsers by injecting polyfills and tries to compile the modern javascript and CSS to code that is compatible with the older browser.

Usage (dev server)

• Start your vite project as normal
• Run npx tvkit@latest serve --browser "chrome 50" in another terminal
• Open http://localhost:3000/ in an old browser to visit your website

tvkit serve

Option	Default value	Description
[target]	http://localhost:5173	The URL of the website that is too new
--port	3000	The port the proxy server is going to run on
--browser		The transpilation target (uses browserslist)
--add		Override feature. Ex --add "es6-module" forces adding systemjs polyfill
--remove		Override feature: Ex --remove fetch forces omitting whatwg-fetch polyfill
--no-css	false	Disable CSS transpilation
--ssl-cert		Path to the SSL certificate for https
--ssl-key		Path to the SSL certificate's private key
--help		Show message per command. Ex: tvkit serve --help

tvkit adds browser aliases for SmartTV platforms: Example --browser "Tizen 5" is aliased to Chrome 63

Start tvkit & servers at the same time

Use concurrently to start both servers at the same time:

// package.json
"scripts": {
  "dev": "concurrently --kill-others-on-fail \"npm:dev:*\"",
  "dev:vite": "vite dev",
  "dev:tvkit": "tvkit serve --browser \"Tizen 4, WebOS 4\"",

Usage (build)

Experimental feature
Use alternative @vitejs/plugin-legacy if you can.

npx tvkit@latest build path/to/build --out path/to/output --browser "chrome 50"

Technology

• SystemJS to polyfill ES modules.
• Babel to transpile javascript on the fly.
• core-js, whatwg-fetch and others to polyfill missing features.
• PostCSS to transpile CSS on the fly using postcss-preset-env.
• And others: Rollup, Acorn, Yargs

Consider funding these projects as they do a lot of the heavy lifting.