Fiddler is a web debugging proxy tool for Mac, Windows, and Linux devices. It allows you to track and inspect HTTP and HTTPS traffic coming to and from web and desktop applications to discover bugs and fix them.
Fiddler allows you to test applications, not just browsers, for bugs. You can even mock requests from applications or modify them, without changing the code, to test any type of app request.
In addition to debugging on Windows, Mac, and Linux devices, you can also debug on mobile phones (both iOS and Android). There is also a Chrome extension you can use for troubleshooting.
To put it in more layman terms, Fiddler allows you to analyze and monitor web traffic to ensure everything is going smoothly, cookies are being transferred, and so on. It allows you to see whether your web application is giving errors and fix them.
You can always use your browser’s built-in inspector mode for some debugging solutions, but not all. Fiddler and Fiddler alternatives provide a wide range of features that you won’t be able to use with your browser’s inspector mode.
For example, it allows you to test mobile apps and desktop apps that are not browsers. Your browser’s tool can only test things inside the browser.
In addition, there are many more features that you can make use of when using Fiddler or a Fiddler alternative. You can mock requests, as mentioned before, or intercept requests.
Fiddler is not the only web traffic monitoring tool out there. Some people have reported that they could not get Fiddler to monitor all network traffic, for example.
Another thing to keep in mind is that Fiddler is an HTTP(S) proxy. That means it will capture all HTTP(S) requests made by the network.
However, it doesn’t do other things like capturing local-host traffic in IE. If you want to capture that traffic, or if you want to view errors below the HTTP level, you might be in need of another tool.
Regardless of why you are unsatisfied with Fiddler, however, there are many great Fiddler alternatives out there you can use.
In this article, I will show you the 10 best Fiddler alternatives for debugging and network monitoring. Let us get into it.
Also Read: Best Open Source Tools For Web Developers
Wireshark is one of the most widely used, if not the most widely used, network protocol analyzers in the world.
As mentioned, Fiddler is an HTTP and HTTPS proxy. If you think there are bugs or errors below the HTTP level, it will be hard to capture them in Fiddler.
In that case, Wireshark will come to the rescue. Wireshark can help you discover server bugs, bugs in the TCP/IP protocol that the browser uses, and layers below that.
Since Wireshark can capture any type of network packet, you can get a lot more information out of it than out of Fiddler.
Think of it as different levels in a pyramid. HTTP is at the top of the pyramid, but there are levels below it that Fiddler won’t be able to capture.
So, what does Wireshark do? What are the benefits of using it?
You can inspect hundreds of protocols using Wireshark and make use of offline analysis. It also supports a wide range of platforms, more than Fiddler seems to support, including Solaris, FreeBSD, NetBSD, and, of course, the top three: Linux, Windows, and Mac.
Wireshark supports decryption for a wide range of protocols, such as IPsec, ISAKMP, and Kerberos. It also supports a wide range of capture file formats.
Another benefit of using Wireshark over Fiddler is that Wireshark is open source. While Fiddler is freeware, meaning you can use it for free, Wireshark allows you to browse and modify the source code to better fit your needs, giving you more flexibility.
I also really liked the amazing community behind the project, as well as the vast range of resources available. For example, there is on-demand Wireshark training on the website to help you get acquainted with the tool, as well as educational conferences and private training.
On GitLab, you can view the source code and track issues and bugs.
All in all, Wireshark is a strong alternative to Fiddler, with a number of benefits, including being open source and offering the ability to capture errors below the HTTP level.
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Like Fiddler, Charles is a web debugging proxy for HTTP and HTTPS network traffic, allowing you to monitor and analyze said traffic. However, Charles does have a number of benefits over Fiddler.
For example, many people say it handles HTTPS better. Also, it handles AMF, displays JSON and other responses in an easy to see tree structure, and has features like the Load & Save Session.
You can view JSON, XML, and other responses either as a tree structure or as text.
You can use the Charles proxy to simulate slower internet connections. This way, you can discover errors and bugs that occur during such connections.
That is made possible with the Bandwidth Throttling tool, which allows you to adjust the bandwidth to any number of bytes per second to land on the exact speed you want to test for.
You can also use Charles as a SOCKS proxy or set up port forwarding, using the Port Forwarding tool, for any TCP/IP or UDP port.
Many people love the Mirror tool, which is another advantage Charles has over Fiddler. The Mirror tool saves responses to a disk, creating a mirror copy of the website you are browsing.
Alternatively, you can click on any node in Charles to save a mirror copy to the disk. However, unlike the Mirror tool, which is not restricted by Recording Settings limits, this alternative is.
Charles has many other useful tools as well, such as the Autosave tool, which saves and clears the recording session at a specific interval, which can be useful during longer recording spans.
There is also the Block Cookies too, which blocks cookies in network requests. It can be used for two main purposes:
- Simulate network activity when cookies are blocked, which a lot of users often do
- See the website as if a spider from Google or another crawler is viewing it, as these spiders often do not support cookies
The Rewrite tool allows you to modify requests by rewriting them. For example, you can add text or a header.
The downside of Charles is that it is not free, and you have to pay at least $50 for a license. However, there is a free 30-day trial, which allows you to test out the tool before using it.
Always check the Charles Buy page for updated pricing information.
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3. HTTP Toolkit
HTTP Toolkit, unlike Fiddler, is open source. It acts as a proxy for HTTP(S) connections.
You can intercept and monitor all HTTP and HTTPS requests, as well as mock requests, modify requests, and rewrite requests. You can also inject errors.
You can capture HTTP traffic from applications such as:
- Desktop browsers
- Android applications
- Android browsers
- Scripting languages
- And a lot more
There are great filtering tools to help you highlight and skim through traffic. With the Pro version, you can run tests with automated mock responses.
HTTP Toolkit is simple and easy to use, and being that it is open source, you can view the source code on GitHub and edit it. However, there is a Pro version as well, which is not open source.
The Pro version will give you access to special features such as automated mock responses. With the Pro version, you can also do things like redirect requests to another server, inject timeouts, simulate connection failures, set advanced customizations, and more.
Fortunately, the Pro version only costs $14/month. There is also a team plan, which costs $22/month per team user, which will give you access to features like centralized billing and team workspaces.
Always check the Pro page for updated pricing information.
Interesting Comparison: GitHub Vs GitLab
Proxyman is a web debugging tool for Mac devices. It allows you to capture and monitor HTTPS traffic requests.
Some things you can do with Proxyman include:
- Pin your favorite apps or websites
- Filter URLs based on protocol
- Customize the layout of your workspace
- Syntax highlighting
Proxyman acts as a man-in-the-middle proxy to log traffic flowing from and to your applications and the SSL server.
You can highlight certain requests or add comments, as well as use a wide range of filters during your testing.
Some people have reported experiencing difficulty using Fiddler to capture mobile traffic, so you can use Proxyman for that instead. With Proxyman, you can capture traffic not only from simulators but from real Android and iOS devices as well.
Proxyman uses the Atlantis framework to monitor and inspect all HTTP and HTTPS traffic coming from your mobile iOS app without requiring you to install any certificate.
Proxyman does require you to purchase a license before using the software. However, the license is a perpetual license, though you will need to renew it if you want to receive updates after a year.
In other words, the license gives you access to the software for as long as you want, with one year of free updates. After that, if you do not renew your license, you can continue using the software, but you won’t get any updated versions.
However, renewing your license comes with a 35 percent discount compared to the base price.
Licenses start at just $59 for one Mac device or two licenses for iOS. However, for just $10 extra ($69), you can double that and get Proxyman for two Mac devices and four iOS phones.
Always refer to the pricing page to see what the software costs in real time, as prices are subject to change at any time.
SmartSniff is an excellent Fiddler alternative because unlike Fiddler, which limits you to the HTTP layer, SmartSniff lets you go below that and debug TCP/IP packets that pass through your network adapter. That can help you discover bugs and errors in the TCP/IP protocol layer, something you can’t really do with Fiddler.
You can then view the data you captured as a sequence of conversations between the client and the server.
One of the benefits of using SmartSniff is that it works on older Windows devices, including Windows XP and even Windows 2000! You can even go earlier and use it with Windows 1998, Windows ME, and Windows NT!
Using Raw Sockets, you can capture data on Windows devices, from Windows 2000 and up, without installing a driver. However, there are some bugs with this method; for example, outgoing SPI packets are not captured.
A somewhat better option would be to use the WinPcap capture driver, which supports all Windows versions, starting from Windows 1998 and including Windows ME, Windows NT, Windows 2000, Windows 2003, Windows XP, and Windows Vista.
However, while WinPcap is available for download, it has not been updated in years. As such, you may experience some bugs when using the driver.
Npcap is a replacement driver that may work.
You can also use the Microsoft Network Monitor Driver.
It is important to note that the last version of SmartSniff was released in 2018. You should still use it if you have an older machine, as not a lot of options exist for such machines.
Also, SmartSniff is available in multiple languages, but the other language versions may not have been updated as frequently. For example, although the Traditional Chinese, Brazilian Portuguese, French, and German versions were last released in 2018, the Galician version was released way back in 2004 and may no longer work well.
All in all, SmartSniff is a good alternative to Fiddler for older Windows versions.
HTTP Debugger is a tool you can use for debugging HTTP API calls between and to back ends. Unlike Fiddler, it is not an HTTP proxy, and you can display proxy-connected traffic.
You can inspect traffic, edit requests, and discover errors. For example, you can edit the request so that you add a header, remove cookies, and so on.
It is a great tool for documenting errors that occur while connecting to and integrating with third-party systems.
You can isolate and fix performance bottlenecks, discover undocumented features that occur when integrating with third-party applications, detect fake authentication and other security issues, decrypt SSL traffic from any application or browser (including Android emulators), and more.
It is also possible to export data from the tool to Excel or JSON, TXT, CSV, and XML formats. This way, you can analyze the data again later.
By creating highlighting rules, you can highlight specific errors or slowdowns. You can also visualize your traffic using the charts the tool gives you.
Again, one of the main benefits of using HTTP Debugger is that it is NOT a proxy. That means that you do not have to change your browser’s configuration for a proxy.
HTTP Debugger is not free, but the license is affordable and allows you to use the software for as long as you want, with free updates for up to a year and free tech support. Licensing starts at $69 per license, but you can get discounts by purchasing licenses in bulk.
For example, you will get a 10 percent discount if you buy 5-9 licenses and a 25 percent discount if you buy 50 or more licenses. A seven-day free trial is available, so you will get a chance to try the software out before using it.
Always check the pricing page to see updated pricing information and available discounts for bulk purchases.
Mitmproxy, like Fiddler, is an HTTPS proxy. Unlike Fiddler, however, it is not only free but open source as well.
It is a great option for debugging, privacy measurement, discovering security issues, and so on.
Mitmproxy aims to give you an interface similar to Chrome’s DevTools, so if you are familiar with that interface, you will find mitmproxy easy to use. Of course, mitmproxy adds a number of features that DevTools does not include, such as replay and request interception.
You can intercept traffic, modify them on route, and then replay them to the client or server again at a later point in time.
You can view the source code on GitHub, join the developer chat on Slack, or ask questions on Stack Overflow. All relevant links can be found on the mitmproxy website.
InProxy is a free web debugging proxy you can use as an alternative to Fiddler. You can capture and analyze HTTP, HTTPS, and WebSocket traffic coming to and from your device.
You can also mock requests or manipulate requests for testing purposes.
One thing that makes inProxy such a great alternative to Fiddler is that not only can you debug HTTP(S) traffic, but you can also debug WebSocket traffic, something that Fiddler does not allow you to do easily out of the box.
In addition, you can also debug local traffic on private networks, including web servers, iOS devices, Android devices, simulators, and emulators.
Both basic and advanced filters can be applied when analyzing traffic. You can decrypt HTTPS traffic and edit cookies that will be associated with each domain.
Documentation to help you learn how to use inProxy is available on the website.
InProxy is entirely free to use. You will not have to pay to download it; just go to the site and download it from the homepage.
9. Request Bin
Request Bin is an interesting alternative to Fiddler. It is a good one, because it allows you to collect HTTP and webhook requests, or subscribe to popular events from different apps, and put them in a “bin” so you can inspect them later for debugging purposes.
Bins are private by default, but you can also create a public bin if you want. You will get a special URL, which you can use to collect HTTP and webhook requests.
Other events you can collect in your bin include RSS feeds, GitHub activity on a specific repository, and more, but that is not the focus of this article.
You can also configure the HTTP response. I suggest checking out the website to learn more.
Surge is a HTTP and full-service network toolbox for macOS. In addition, it acts as an HTTPS proxy, a SOCKS5 proxy, and a SOCKS5 proxy, making it a great alternative to Fiddler for those latter two purposes.
You can monitor HTTP requests, modify them, and discover bugs.
One of the benefits of using Surge is that it offers a high-performance experience, with low system resource consumption on your end, but with the ability to run without interruption with excellent performance.
It supports local DNS mapping, flexible rules for proxy forwarding, and a metered network mode. The metered network mode allows you to set which processes can access the internet, and it is a good mode to use when you are on a metered or limited network, such as a hotspot.
There is even an iOS version, which is like the Mac version but for iOS devices. You can connect the Mac version to the iOS version over Wi-Fi or a USB and monitor and analyze iOS traffic on the Mac device.
Surge costs $49.99 for a lifetime, single license. It is best to refer to the purchase page to see prices in real time.
I recommend Wireshark as the best Fiddler alternative. Unlike Fiddler, it is open source, so it gives you more flexibility, and you know it will remain free forever.
Also, Wireshark does not limit you to the top HTTP(S) layer and instead allows you to debug at much lower layers, such as in the TCP/IP layer.
Tom loves to write on technology, e-commerce & internet marketing. I started my first e-commerce company in college, designing and selling t-shirts for my campus bar crawl using print-on-demand. Having successfully established multiple 6 & 7-figure e-commerce businesses (in women’s fashion and hiking gear), I think I can share a tip or 2 to help you succeed.