Fiddler is one of the best online tools available right now for monitoring and analyzing web traffic. In Fiddler, you can easily find out almost everything with respect to web requests like Headers, Text View, Syntax View, Cookies, etc. of a request. All in all, this becomes very helpful for a developer or user who is analyzing web traffic requests. Review collected by and hosted on G2.com.

As every good software, Fiddler too has a few issues. If used for too long to analyze web requests, Fiddler becomes too slow and at times becomes unresponsive as well. The ability to selectively filter requests is not available in Fiddler and can be a nice feature addition in the future. Review collected by and hosted on G2.com.

I use it mainly to debug cloud service calls for the application I support. It tracks every service call with great details. Review collected by and hosted on G2.com.

It can slow down your machine if you have too many things open because traffic is rerouted through it. Also if you don't close it correctly and leave it to crash, it could stop your internet connection. Review collected by and hosted on G2.com.

I use Fiddler more than any other "helper" application that we run at work. The ease of access to the detail Fiddler providers in what's going on in my web requests goes way beyond anything else I've used. When I've exhausted all other debugging options (which is often) Fiddler always bails me out because I can see what's going on behind the scenes and along the wire. Review collected by and hosted on G2.com.

While this isn't totally Fiddler's fault, I sometimes forget to close Fiddler and it gets in the way of publishing or other tasks that fail while a proxy is running. But it's easily fixed by simply closing Fiddler Review collected by and hosted on G2.com.

I was using Postman and then wanted to try Fiddler too to compare REST call response. So this is a brief review on just the REST call feature. I used Fiddler for just a basic usage and it ran the calls that I wished to test. Overall it does that task for you. I haven't tried the other features/tools or advanced features available, but it appears there are many, so I assume advanced developers are using or demanding such advanced features. Review collected by and hosted on G2.com.

It wasn't intuitive to install (for Mac) users. I understand it is on BETA, so it's somewhat expected. It's also expected in general that installing things via terminal is not always straightforward, but installing a desktop app on Mac, users typically expect a one-step process through installation wizards. It required installing Mono Framework first via terminal, but there are directions on the Telerik blog to follow. If I recall, I had a few errors trying to install Mono that I wasn't able to resolve, but eventually tried to install Fiddler anyways, and it ran. The other thing was the setup to get going also wasn't intuitive. Postman and other applications just have you post the URL, the data, and run. Fiddler, however, had several options to enter your server information. I believe the advantage of that is direct connection. For my purpose, I just needed to simply enter the HTTP URL, info, and run, so to quickly test. It is possible because I am not too familiar with all the backend configuration which Fiddler gives options to, that it is confusing for me to fill out and make use initially. I would have to further investigate if I were to continue to test REST calls, using Fiddler tools. Review collected by and hosted on G2.com.

Fiddler makes REST API debugging quite Simple. At every REST call, just put a debugger and see the actual calls that are being made, with complete header and payload. Also, it's ability to repeat requests to a website which allows me to debug at a rapid speed. Review collected by and hosted on G2.com.

Lot of warnings/certificates acceptance when enabling decryption of HTTPS data. Otherwise, I think it is the simplest tool with all the functionalities working smooth as expected from it. Review collected by and hosted on G2.com.

Fiddler made debugging APIs easier and comprehensive. It provides the user with complete details of each network requests and provides a user-friendly UI where you can disect information of each network request. It also has a filter to only see requests coming/going to a specific domain. Outputs can be viewed in JSON, XML and RAW formats. It works well with PostMan. Review collected by and hosted on G2.com.

The usefulness of this product overcomes one thing I don't like about it which is the UI. It looks like an old software. Review collected by and hosted on G2.com.

Fiddler is an amazing tools I have been using for about 4 years now. It makes REST api debugging a breeze. At every rest call, just put a debugger and see the actual calls being made, with complete header and payload.

And the best part it decrypts https data too (if allowed).

Data can be seen in any format (xml, json or raw)

Requests can be composed at runtime to trigger various cases.

Rerun is trivial of same requests with modifications.

Fiddler rules to handle automated responses. Review collected by and hosted on G2.com.

Its difficult to say, as its been helping me a lot with debugging. But a filter with specific domains might be helpful. Currently I have to search for the domain I am debugging for.

Lot of warnings/certificates acceptance when enabling decprtion of HTTS data (expected though)

Difficult to connect with Android/iOS devices Review collected by and hosted on G2.com.

It's a very good and easy to use tool to monitor incoming and outgoing data over http/https. It's very handy for API testing. Review collected by and hosted on G2.com.

GUI is not as good as Postman. History of API calls is not maintained. Review collected by and hosted on G2.com.

Its simple and comprehensive interface is the most interesting part of the application. It is really useful since it can offer you many necessary options when performing any test, whether it be performance and/or communication. Review collected by and hosted on G2.com.

The interface is possibly too outdated compared to today's applications. Review collected by and hosted on G2.com.

We needed fiddler to know how the file uploading failed, and fiddler did it very nicely by telling the type of error. It operates in between the requests which make it very unique. Certificates can be attached very easily. It has caches analyzing which is perfect tool for getting to know if our web app behaved correctly or not. We get to know times of all requests and hence improve the api's which causes the bottleneck. Review collected by and hosted on G2.com.

The 1000 bucks for the complete support package for an year looks quiet over priced. It can not change the post variables. Review collected by and hosted on G2.com.