How do I fix "TypeError: Failed to fetch"?

Open the Network tab, find the failed request, and read its address and status. Open that address directly in the browser to see if the server answers. Check production settings for localhost or http:// addresses.

TypeError: Failed to fetch

Browser console

What it means

The browser could not complete the request at all, so there is no status code to read. The server may be down, unreachable, blocked by CORS, or at the wrong address.

Why it happens

The API address is wrong in production, or still points at localhost.
CORS blocked the response (check the console for a CORS message just before).
The backend is down, paused or sleeping.
An ad blocker or browser extension blocked the request.

How to fix it

Open the Network tab, find the failed request, and read its address and status.
Open that address directly in the browser to see if the server answers.
Check production settings for localhost or http:// addresses.

Let your AI find the cause

Paste this into Claude Code, Cursor, Lovable or whichever AI built your app. It looks first and changes nothing until you have read the answer.

My app shows 'TypeError: Failed to fetch'. Without changing anything yet, find the request that fails, the exact address it calls in production, and tell me how to check whether that server is up and allows my site.