TypeError: Failed to fetch / NetworkError when attempting to fetch resource
The browser couldn’t complete the request at the network level — CORS, DNS, offline, blocked mixed content, or the server refused the connection.
Failed to fetchTypeError: Failed to fetchNetworkError when attempting to fetch resource Meaning
fetch() rejects (instead of resolving with a status) only when no HTTP response could be used: the server was unreachable, the request was blocked by CORS or the browser, or it was aborted. The console usually has a second, more specific message right above it.
Common causes
- CORS blocked the response (check console for the CORS message)
- Server down or wrong host/port
- Mixed content: HTTPS page calling an HTTP API
- Ad blocker/privacy extension blocking the URL
- Self-signed or invalid TLS certificate
- Request aborted by navigation or AbortController
⚡ Quick fix
- Read the console message just above “Failed to fetch”
- Open the API URL directly in a tab — does it load?
- Use HTTPS for the API when the page is HTTPS
- Try with extensions disabled (incognito)
Detailed fix by platform
JavaScript
- Wrap fetch in try/catch and show a network-specific message; distinguish
err.name === 'AbortError'.
How to diagnose
- Console — CORS, mixed content or certificate message?
- Reachability — Does the URL respond outside the app?
- Network tab — Is the request marked (blocked), (failed) or CORS error?
🔧 Still not fixed?
Many errors look alike. If the steps above didn’t solve it, one of these is probably what you’re facing:
Similar errors
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Other ways to find it
Where this error sits
Origin: On your device. Errors that are often confused with or caused by this one (click to open):
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Last updated 14 Oct 2026