Best Free Application Performance Monitoring Tools in 2025

There are several types of monitoring available in an application performance monitoring tool. Some of them are:

• Digital Experience Monitoring (DEM)
• Application Discovery
• Tracing and Diagnostics
• Infrastructure and Cloud Monitoring

These types of monitoring help to identify issues in the application and provide insights into how to improve its performance.

APM stands for Application Performance Monitoring. The software suite includes digital experience monitoring (DEM), application discovery, tracing, and diagnosis, along with monitoring for infrastructure and cloud services.

A 502 Bad Gateway error occurs when Cloudflare is unable to establish contact with your origin web server. There are two possible causes:

• 502/504 from your origin web server: Cloudflare returns a Cloudflare-branded HTTP 502 or 504 error when your origin web server responds with a standard HTTP 502 bad gateway or 504 gateway timeout error. This can be caused by a variety of factors, such as:
  • Excessive server loads
  • Crashes or network failures
  • Applications or services that timed out or were blocked
• 502/504 from Cloudflare: In rare cases, Cloudflare itself may experience a temporary outage or issue that can cause a 502 error. If you believe this is the case, you can check the Cloudflare status page to see if there are any known issues.

Cloudflare is used for website optimization, security, and performance via its content delivery network (CDN). It optimizes a website's speed and reliability and protects against online threats by mediating between its server and visitors.