How Fiddler Everywhere makes web debugging simpler
Tags: fiddler, testing, debugging, webdev
Published: 2020-08-18 10:16:31

As developers – whether new or experienced, we are always afraid of bugs. These could appear in the form of unexpected results or errors in our websites and apps. Problems like these are where tools like Fiddler Everywhere have been saving time and effort. In this post, we’re going to explore some situations where Fiddler Everywhere makes debugging simpler for developers.

![Download Fiddler Everywhere Now](https://dev-to-uploads.s3.amazonaws.com/i/8m1338d0pf7y9gmmrkxd.png)

Fiddler Everywhere is the next generation cross-platform network debugging proxy tool, which just [came out of beta](https://bit.ly/3aiQ1Qe) recently. The tool is trusted by developers for over a decade and is used to inspect and debug HTTP(S) traffic requests between your computer and the internet. If you haven’t tried it yet, [download it now](https://bit.ly/3gWlE4v).

##Identify errors 

Fiddler Everywhere inspects every request made to the server as well as the response received. As the requests come in, they are logged by Fiddler Everywhere. The request log provides you a perspective of the activity going on in the background when the browser calls your website.  

If at any point, you receive an unexpected response or an error, Fiddler Everywhere can promptly point out the cause. The issue could be something as simple as a wrongly entered file name in the code. While it could be a daunting task to pinpoint the file causing the error, Fiddler Everywhere would throw a 4XX error, which then can be [easily debugged](https://bit.ly/2CrOgDQ).

![Alt Text](https://dev-to-uploads.s3.amazonaws.com/i/uvh3jzjt7phhquviqbn8.png)

For example, a 404 error would indicate that the file name does not match the available files on the server, or the file doesn’t exist. Once identified, it is much simpler to rectify the error.

##Mock user conditions  

Fiddler Everywhere allows you to simulate situations faced by your user. For example, your user might be working on a slower internet connection or entirely offline. Fiddler Everywhere enables you to create rules that add a delay while loading the website to replicate the network latency. The same can applies to check drop requests.

![Alt Text](https://dev-to-uploads.s3.amazonaws.com/i/ewxod6722kuvm8q49jci.png)

Fiddler Everywhere also tracks the response size and time taken to be transmitted. This data can be of use to highlight files that are heavy and take longer to load.

Additionally, using the Fiddler Everywhere Auto Responder you can create mocking rules for your API. This ability is especially useful when you want to test your app without the live APIs or are behind a firewall.

##Test APIs 

The Fiddler Everywhere Composer can be used to quickly test API requests and make sure that the server responds as expected. For example, if the API fails to return a response or doesn’t provide the expected response, you can open the request in the composer, modify the headers, and execute it to test the request. 

![Alt Text](https://dev-to-uploads.s3.amazonaws.com/i/oh21st72shjnu2or8a2n.png)

If everything is working fine, you should get a 2XX status, else a 4XX error if there is an issue with the HTTP request or a 5XX error if there is an issue with the server. You can identify several common problems like unauthenticated requests, invalid requests, internal server errors, and service overload.

Alternatively, you can use the Fiddler Everywhere Composer to test new APIs or the API user interface.

##Saving sessions 

Fiddler Everywhere takes the pain out of repeatedly working with web requests. Fiddler Everywhere has intuitive features that help you streamline the debugging process. The filters across every category allow us to inspect limited traffic from a particular domain, a selected browser, or even a specific file type and status code. You can add multiple filters as required.

![Alt Text](https://dev-to-uploads.s3.amazonaws.com/i/krch25ti2mtmywem67uy.png)

Additionally, you can select individual sessions or multiple sessions. You can then save them and open them in a separate tab. Fiddler Everywhere also allows you to put notes and comments on your saved sessions. This feature is useful when you want to share the requests with your teammates, who can then continue from where you left.

##Try out Fiddler Everywhere

These are some of the ways that Fiddler Everywhere is known to simplify the web debugging process. Let us know the ones that you use in the comments below.

If you are new to Fiddler Everywhere, check out the video below to help you get started quickly. 

{% youtube y22Zp3NR3DE %}

Happy debugging!