Guides
How-tos and explainers on keeping websites up: HTTP status codes, checking whether a site is down, setting up monitoring and alerts. Every guide ends with the free tool that checks it for you.
Monitoring concepts explained
Definitions for the terms a monitoring setup rests on: uptime, TTFB, latency, rechecks, blacklists, status pages and synthetic versus real user data.
- How to Calculate Uptime
- What is DNS Blacklist
- What is a status page and what belongs on one
- Why Your Website Needs Uptime Monitoring
- Recheck strategies: confirming a new status before alerting
- What is server monitoring?
- Synthetic vs real user monitoring: what each one catches
- TTFB vs response time vs latency: what each one measures
- What is uptime?
Fix it: guides for the errors people actually hit
One guide per error message: what it means, why it happens, the exact fix per platform, and how to tell a local problem from a real outage.
Monitoring guides: every check type, set up step by step
Set up any HostTracker check type: what each setting does, what to set it to, and which type answers the failure you are worried about.
- How to Monitor a Website with an HTTP Check
- Domain Expired or SSL Certificate Expired? How to Tell
- How to Monitor Domain Registration Expiration
- How to Get Alerts from HostTracker
- How to Set Up API Monitoring in HostTracker
- Assertion Mode: Complete Response Validation Reference
- How to Monitor SSL Certificate Expiration
- How to Set Up a Website Content Check
- CPU, RAM and Disk Monitoring Setup Guide
- Database Monitoring Setup Guide
- DNSBL Check: Monitor DNS Blacklist Listings
- How to Send HostTracker Alerts to Slack
- SNMP Monitoring Setup Guide for Network Devices
- How to Set Up Page Speed Monitoring
- How to Set Up a Ping Check (Step-by-Step Guide)
- Russian Blacklist (RKN) Check: Setup Guide
- How to Set Up a TCP Port Check (Full Guide)
- How to Set Up a Transaction Check (Step-by-Step)
- Web Risk Monitoring: Detect Malware and Phishing Flags
HTTP status codes explained
The first digit of a status code sets the family: 1xx informational, 2xx success, 3xx redirect, 4xx client error, 5xx server error.
- 1xx informational status codes
- 200 OK: what it means and what it hides
- 2xx success status codes
- 300 Multiple Choices: the code you will almost never see
- 301 vs 302: permanent and temporary redirects
- 303 See Other: the redirect after a form POST
- 304 Not Modified: why it is a success, not an error
- 3xx redirection status codes
- 403 Forbidden: Causes, Fixes and Bot Blocks That Fool Monitors
- 404 Not Found: Broken Links, Soft 404s and When to Use 410
- 429 Too Many Requests: Rate Limits, Retry-After and False Alarms
- 4xx Status Codes Explained: What Client Errors Really Mean
- 500 Internal Server Error: Causes, Logs and How It Differs From 502
- 502 Bad Gateway: What Broke Behind the Proxy and How to Find It
- 503 Service Unavailable: Overload, Maintenance and Retry-After
- 504 Gateway Timeout: Slow Backends, Timeouts and 502 vs 503 vs 504
- 5xx Status Codes Explained: When Your Server Is the Problem
How to check a website: the practical guides
Guides for the checks people run when a site misbehaves: is it down, how fast is it, who hosts it, is the port open, has the certificate expired.
- Is the website down for everyone or just me?
- How to check website speed
- How to check server response time
- How to check if a port is open
- How to check when an SSL certificate expires
- How to find out who hosts a website
- WHOIS lookup: what a domain record tells you
- How to check if an IP or domain is blacklisted
- How to check DNS propagation