HTTP troubleshooting
429 Too Many Requests
Your uptime monitor detected that the server has rate-limited the connection. This means the server blocked the request because the monitor or other visitors have sent too many requests in a short window of time to protect the site from crashing.
What 429 Status Code Means
- 1.
Rate limiting limits hit
The server or an attached security shield has a strict rule on how many visits a single IP address can make per minute.
- 2.
Aggressive monitoring intervals
The uptime monitor is checking the website too frequently, causing the server to mistake it for a cyber attack.
- 3.
Uptime monitor behavior
Our monitor flagged this because the server refused to process the page and actively told the monitor to stop sending requests.
Troubleshooting checklist
- 1.
Check rate limit rules
Review your web application code, API gateway, or hosting settings for active rate limiting or throttling plugins.
- 2.
Inspect security firewall logs
Look at your Cloudflare, AWS, or web application firewall (WAF) dashboards to see if they triggered a block.
- 3.
Review monitor frequency
Check how often your uptime monitor is set to ping the URL (e.g., every 10 seconds versus every 5 minutes).
- 4.
Audit total concurrent traffic
Look at your server analytics to see if a sudden spike in real users or bot traffic is triggering the rate limiter for everyone.
How to Fix It
- 1.
Whitelist monitor IP addresses
Add our uptime monitor IP addresses to your server's rate limit exemption safelist so it is never blocked.
- 2.
Adjust monitoring interval
Change the check frequency in your uptime monitor dashboard to give the server more breathing room between pings.
- 3.
Raise rate limit thresholds
Increase the maximum allowable requests per minute inside your API configuration or firewall settings.
- 4.
Implement retry headers
Configure your server to send a 'Retry-After' header so the monitor knows exactly when it is safe to check again.
After the Service is Fixed
- 1.
Verify with Uptime Monitor
Confirm that the monitor returns to a healthy green status once the rate limits are updated or the block cools down.
- 2.
Track traffic patterns
Watch your site traffic to see if legitimate visitors are accidentally hitting the same rate limit walls.
- 3.
Optimize API response cache
Cache common API answers so the server doesn't have to work as hard for every single incoming request.
- 4.
Set up automated alerts
Configure a notification to tell you if the rate limiter is triggered frequently, which could mean a real bot attack is happening.