Port guide

localhost:5173

Port 5173 is widely associated with Vite development servers and modern frontend projects.

Fast checklist

  1. 1 Run your frontend development command.
  2. 2 Use the local URL printed in the terminal instead of guessing.
  3. 3 If port 5173 is busy, the server may move to another nearby port.
  4. 4 Open the exact printed URL, including the path if one is shown.

Quick diagnostic checks

Check the Vite listener lsof -i :5173

Use this when the browser says the site cannot be reached. No listener usually means the dev server stopped or never started.

Open the exact local URL http://localhost:5173/

If the terminal prints 5174, 5175, or another port, use that printed address instead of forcing 5173.

Prepare phone testing npm run dev -- --host 0.0.0.0

Many frontend dev servers bind to localhost only by default. Network access needs the server to listen on a reachable interface.

Live request check

What this page sees

Detecting what the server sees...
Public IP Checking...
Request line Checking...
HTTP request headers
Loading headers...

Sensitive headers such as cookies and authorization tokens are filtered before display.

When to use localhost:5173

Use this URL when your local dev tool says the application is available on port 5173.

If the terminal prints a different port, follow that terminal output instead of forcing 5173.

Common fixes

Refresh after the dev server finishes compiling, check for dependency errors, and make sure your browser is not using an old HTTPS version of the URL.

Related localhost guides

FAQ

Why did my Vite app open on a different port?

Another process may already be using port 5173. Many dev servers automatically choose a nearby free port.

Can my phone open localhost:5173?

Your phone cannot use localhost to reach your computer. Use your computer LAN IP plus the same port, and make sure the dev server allows network access.

What should I check first when this localhost port does not open?

Check whether the development server is still running, then copy the exact URL printed in the terminal. If the terminal shows a different port, use that port instead.

Can I replace localhost with 127.0.0.1 for this port?

Usually yes for browser testing on the same computer. If one works and the other fails, check host binding, IPv6 behavior, certificates, or your hosts file.

Why does the browser show a blank page or JSON on this port?

The service may be an API, a backend health route, or a server that does not serve a polished page at /. Try the documented path such as /api, /docs, /admin, or the route your framework prints.