rstacruz/nprogress

NProgress is a tiny JavaScript library that adds the thin loading bar you see at the top of pages on YouTube and Medium, that slim colored line that slides across the top of the browser and fills in as a page loads. It's a small visual cue that tells users something is happening, which reduces the feeling of a page being "frozen" or unresponsive. For a vibe coder building a web app with tools like Lovable or Bolt, or anyone adding polish to a website, NProgress is one of the easiest UI improvements you can add. You install it with one command, then call two functions in your code: one to start the bar when a request begins, and one to complete it when the request finishes. The whole library is minimal by design, the CSS file is tiny and easy to customize by changing a single color value. It works great for any situation where your app fetches data or navigates between pages, giving users visual feedback without a jarring full-page spinner. It's particularly popular with older web frameworks, but it works with any JavaScript project. The library is well-established and used across thousands of production websites, it's the kind of small, focused tool that just does one thing reliably. Adding it to a project built on Cursor or Replit is straightforward even without deep coding knowledge, as the integration typically takes just a few lines.