Are there less expensive (or free) alternatives to Charles proxy?

Question

Does anybody know a free alternative to Charles (an HTTP debugging proxy), preferably with a GUI and similar features?

Features that I'm interested in:

• Inspect HTTP requests/responses (header, body, etc)
• JSON syntax highlighting and formatting
• Request filter (by host, URL, etc)
• Search
• Would be awesome if it could render HTML (Charles can't do it)

I’m willing to sacrifice features in exchange for not paying the $50 license fee currently required to license the first seat of Charles proxy suite of tools.

Answer 1

You can also check out mitmproxy which even has a web interface. You can inspect HTTP request/responses and even filter requests by certain parameters.

It doesn't render HTML like you asked but it sure gives out the raw response which might be enough.

Another suggestion I can think of is the developer tools in Firefox which render HTML and also support request filtering. You can obviously inspect HTTP requests in Firefox too.

Answer 2

Proxyman is a commercial tool exclusively built on native macOS and it's designed with intuitive UI, so you can start proxying HTTPS easily and quickly.

You can intercept the HTTP traffic from iOS and Android devices too. Proxyman also has Built-in automatic scripts to override HTTP Proxy and certificate for iOS Simulator and Android Emulator.

Disclaimer: I'm a creator of Proxyman.

Answer 3

Take a look at HTTP Toolkit. It's a great Charles Proxy alternative that I've been building, and I think it's exactly what you're looking for. It:

• is 100% open source, and all the features you're looking for are free
• has a fully powered editor for request & response bodies, powered by the same internals as VS code
• does targeted interception - it can launch browsers, terminal windows, or Android interception all automatically for you, and then intercepts only that specific traffic. That means no interference with the rest of your machine, no noise from other apps, and no need to globally trust an new certificate authority.
• requires zero setup: open the app, click a button, instant HTTPS interception
• has a far more powerful & flexible rules engine for building rules to rewrite and breakpoint your traffic
• looks beautiful, is much nicer to use, and works fully cross-platform

A picture's worth a 1,000 words:

Answer 4

Two products that are adjacent to Charles are :

1. Fiddler

Fiddler for macOS runs on mono, so don't expect the same smooth appearance like you get on Windows.

2. WireShark

Wireshark is more relevant for capturing everything over the wire (and then filtering by protocols) and not directly useful(easily) for scripting HTTP responses on the fly.

Answer 5

User BurpSuite by PortSwigger

https://portswigger.net/burp

The community edition is well enough to inspect HTTP/HTTPs traffic and more, only it cannot render HTML.

Answer 6

You can also check out Proxycat which has a macOS version and an iOS version.

Answer 7

You can also use an open source backed tool Requestly for HTTP Debugging Proxy.

I personally find Browser extension easier to use. You can also use desktop app if you are working with a desktop app.

As per your requirement:

• Inspect HTTP requests/responses (header, body, etc) - It can intercept and modify requests and responses.
• JSON syntax highlighting and formatting - It supports.
• Request filter (by host, URL, etc) - It does, also have some other filters like Method.
• Search - Yes.
• Render HTML (Charles can't do it) - Not sure how you want to use it, but it can insert JS,CSS to the webpages.

It is paid and commercially supported software, but a free tier with 3 active filters and limited functionality exists.