Типы мониторов
Website (HTTP) monitors
How the HTTP check requests your URL, which status codes count as up, how redirects, timeouts and slow-response warnings work, and how to fix common errors.
- API type
http- You enter
- URL
- Runs at most every
- Plan minimum
- Needs
- None
- FastPing resolves the hostname from Helsinki. When it has both IPv4 and IPv6 addresses, the IPv4 address is used.
- It connects and, for
https://URLs, validates the TLS certificate strictly: an expired, self-signed or incomplete certificate chain fails the check, just as it would for an API client. - It sends the request with the User-Agent
FastPing-Monitor/1.0 (+https://fastping.app)and follows up to 5 redirects (each new address is checked again; a 303 redirect switches to GET). - It reads the response status and up to 512 KB of the body, then closes the connection.
The monitor is up when the final status code is accepted, down when it is not or when no response arrives, and in warning when the response is slower than your threshold. The response time shown is the time to first byte: DNS lookup, connection, TLS handshake and the server's processing time until the first byte of the response.
| Field | API option | Default | Notes |
|---|---|---|---|
| URL | url | Required | http:// or https:// address; https:// is added when you leave out the scheme |
| Method | method | GET | One of: GET, HEAD, POST, PUT, PATCH, DELETE, OPTIONS |
| Expected status codes | expectedStatus | None | Up to 60 characters |
| Timeout (seconds) | timeout | 15 | 2 to 60 |
| Warn if slower than (ms) | maxMs | None | 0 to 60,000 |
| Follow redirects | followRedirects | On | |
| Check interval | interval | Your plan's minimum | From your plan's minimum up to 24 hours |
Expected status codes
Leave the field empty to accept any 2xx or 3xx code (200 to 399). To be stricter, list exact codes separated by commas, such as 200,204, a class such as 2xx, or a range such as 200-299. You can mix them: 2xx,301.
Method
GET is the safe default. HEAD skips the body, which saves bandwidth on large pages, but some servers answer HEAD with 405 or with a different status than GET. If you see unexpected 405 errors, switch back to GET.
Follow redirects
On by default, so http:// to https:// and trailing-slash redirects are followed to the final page. Turn it off when the redirect itself is what you want to check (see the example below).
Custom headers
Website monitors send no custom headers. For a URL that needs an Authorization header or a specific Accept header, create an API (JSON) monitor and leave its JSON path empty: it then checks the status code only, like a website monitor.
| Goal | Settings |
|---|---|
| Home page is up | URL https://example.com, everything else default. |
| Plain HTTP still redirects to HTTPS | URL http://example.com, Follow redirects off, Expected status codes 301,308. |
| Health endpoint that answers 204 | URL https://example.com/healthz, Expected status codes 204. |
| Early warning before users notice slowness | Warn if slower than 1500 ms. You get a warning, not a down alert, when the time to first byte exceeds 1.5 s. |
| Message | What it means | What to do |
|---|---|---|
HTTP 503 | The server answered with a status code that is not accepted (by default anything outside 200 to 399). | Look at the server or application logs for that time. If the code is expected (for example 401 on a protected URL), add it to Expected status codes. |
Timed out after 15s | No response headers arrived within the timeout. | Check server load and slow queries. If the endpoint is legitimately slow, raise the timeout (up to 60 seconds) and use "Warn if slower than" for early warnings. |
connect ECONNREFUSED 203.0.113.10:443 | The host answered but nothing accepts connections on that port, or a firewall rejects them. | Make sure the web server is running and listening on the right port, and that the firewall allows FastPing. |
Could not resolve shop.example.com. | DNS returned no address for the hostname. | Check the A/AAAA records with the DNS lookup tool. A recently created record may still be propagating. |
Hostname resolves to a private or reserved address. | The hostname points to an address such as 10.x, 192.168.x or 127.0.0.1, which FastPing never connects to. | Monitor the public address of the service. Internal services cannot be monitored from the internet. |
certificate has expired | The TLS certificate presented for the hostname is past its expiry date. | Renew the certificate and reload the web server. Add an SSL certificate monitor to be warned next time. |
unable to verify the first certificate | The server sends its certificate without the intermediate certificate(s). Many browsers cope by fetching or caching intermediates; strict clients such as FastPing, curl and most API clients do not. | Configure the full chain (with Let's Encrypt, use fullchain.pem rather than cert.pem). |
self-signed certificate | The certificate is not issued by a public certificate authority. | Use a certificate from a public CA. FastPing does not skip certificate validation. |
Hostname/IP does not match certificate's altnames: … | The certificate does not cover this hostname (a common case is www.example.com missing from a certificate for example.com). | Issue a certificate that includes the hostname, or monitor the hostname the certificate covers. |
socket hang up | The server closed the connection before sending a response. | Often a proxy, WAF or rate limiter dropping our request. See the troubleshooting guide on firewalls. |
Too many redirects. | More than 5 redirects in a row, usually a redirect loop. | Open the URL in the Website checker tool to see the chain, then fix the loop. |
The Website checker shows the same request with a timing breakdown (DNS, connect, TLS, first byte) and the full redirect chain. If the error only appears from FastPing, see False alerts, firewalls and allowlisting FastPing.