Deep network insight with Fiddler
Fiddler by Progress Telerik is a trusted web debugging tool that captures and inspects HTTP and HTTPS traffic with precision. Popular among developers and testers, it provides a clear view of client–server communication, making it easier to diagnose issues, test APIs, and refine application performance.
Fiddler allows users to intercept, log, and modify requests and responses in real time. Features like breakpoints, traffic rules, and custom request composition make it especially useful when debugging complex web applications. With Fiddler Everywhere, the tool extends beyond Windows to support macOS and Linux, and it can capture mobile traffic by routing devices through a proxy. Developers can also take advantage of FiddlerScript and custom rules to tailor workflows and automate repetitive tasks.
A versatile toolkit for developers
Fiddler also brings valuable visibility into HTTPS traffic. By decrypting encrypted sessions, it reveals certificate chains, TLS versions, and cipher details, helping developers identify weak configurations or anomalies. While not a vulnerability scanner, its transparency into encrypted communications is a significant asset for both debugging and basic security assessments. The tool does come with a learning curve, but the extensive documentation and active support channels make adoption manageable for most users.
Final thoughts
Fiddler strikes a strong balance between depth and flexibility. It remains focused on web debugging but adds enough customization and TLS visibility to support a wide range of professional use cases. For developers or testers who need detailed insight into network activity, it continues to be a reliable and well-supported choice.
Pros
- Captures and inspects HTTP/HTTPS traffic with detail
- Cross-platform support via Fiddler Everywhere
- Customizable with scripts and rules
- Provides TLS and certificate visibility
Cons
- Steep learning curve for advanced features
- Not a full security testing suite
