mitmproxy

Overview

mitmproxy is a free toolkit for intercepting and working with HTTP and WebSocket traffic, including HTTPS. It is best suited to developers and other technical users who need to inspect or alter network exchanges.

It is a particularly useful choice when requests and responses need to be changed in transit, saved, or replayed. Readers looking for a general-purpose proxy service rather than traffic inspection and control should look elsewhere.

Key features

Inspect, edit, and replay exchanges

mitmproxy can intercept HTTP and HTTPS requests and responses and modify them as they pass through the proxy. Breakpoint rules allow selective pauses, while replay and response mocking support workflows that need to revisit exchanges or test against a simulated response. WebSocket inspection extends its reach beyond conventional request-response traffic. These controls are valuable for debugging, but they suit users comfortable configuring proxies and working with intercepted traffic.

HTTP conversations can be saved for later analysis, and client requests or recorded server responses can be replayed. HTTP/3 client replay is currently broken, however, and HTTP/3 support has been extensively tested only with cURL. Teams whose work depends on broader HTTP/3 replay should treat that limitation as decisive.

Interfaces and modes

The interactive console, browser-based mitmweb interface, and non-interactive mitmdump output cover different working styles, from inspecting traffic interactively to terminal-oriented workflows. Proxy modes include regular, local capture, WireGuard, reverse, transparent, TUN, upstream, SOCKS5, and DNS. That breadth makes mitmproxy adaptable to varied network setups, though it also puts configuration choices in the user's hands.

Addons and certificates

Python addons can react to events, change proxy behavior, and expose commands for users to invoke. This makes the tool extensible for workflows that go beyond its built-in controls, especially for users able to write Python. Its certificate authority generates interception certificates on the fly, enabling SSL/TLS traffic inspection.

WireGuard mode can capture traffic from external devices or individual Android apps, a practical option for mobile traffic analysis. The project says mitmproxy does not phone home or check for updates.

Pricing

mitmproxy is free and open source. The mitmproxy plan costs nothing and includes request and response editing, breakpoint rules, traffic replay, response mocking, WebSocket inspection, and proxy chaining. There are no paid tiers or seat and quota limits to weigh in this plan.

Installation options include Windows, macOS, and Linux instructions, PyPI installation, and official Docker images. One operational trade-off affects precompiled binaries and Docker images: their dependencies are frozen at release and cannot be updated in place. The project recommends updating regularly, so users of these packages need to keep up with releases rather than expect dependency updates within an installed build.

Platforms

mitmproxy supports Linux, macOS, Windows, web, and self-hosted use. The web interface is mitmweb; the project also documents installation for the three desktop operating systems and offers PyPI installation and Docker images.

Who it's for

Developers, security practitioners, and technically confident users who need visibility into HTTP traffic, in-flight editing, or replay will find a capable set of tools in one free package. Python addon support makes it a better fit for users who want to customize proxy behavior. WireGuard capture can also serve workflows involving external devices or individual Android apps.

It is a weaker fit for users who want a managed service, a minimal setup, or dependable HTTP/3 client replay. Those requirements point away from mitmproxy's strengths or run into its documented limitations.

Pros and cons

• Pros: Three interfaces let users choose interactive console, browser GUI, or non-interactive terminal output.
• Pros: Broad proxy modes, traffic editing, recording, replay, and response mocking cover many inspection workflows without a paid plan.
• Pros: Python addons and WireGuard capture provide routes to custom behavior and mobile traffic analysis.
• Cons: HTTP/3 client replay is broken, and HTTP/3 testing has been extensive only with cURL.
• Cons: Dependencies in precompiled binaries and Docker images cannot be updated in place, so users need to update regularly.
• Cons: Proxy configuration and certificate interception make it a tool for technical users, not a turnkey service.

Alternatives

Privoxy is another free option for Linux, macOS, Windows, and self-hosted use; consider it when a free proxy tool is a better match than mitmproxy's traffic-inspection workflow.

3proxy is freeware and open source for Linux, macOS, Windows, and self-hosted use. Choose it when that general-purpose platform fit matters more than mitmproxy's editing and replay controls.

Squid is free, self-hosted proxy software for Linux, macOS, and Windows, with third-party commercial support potentially available. It is a reasonable alternative when self-hosted proxy software is the priority.

Cloudflare Gateway offers a free plan for up to 50 users with standard log retention of up to 24 hours, alongside a $7 a month pay-as-you-go plan billed monthly. Consider it when those plan terms and its Android, iOS, Linux, macOS, web, or Windows platform coverage fit better.

Skyhigh Private Access is a paid alternative with custom pricing.

Zscaler Private Access is a paid alternative with no free plan and custom pricing.

Check Point Harmony SASE is a paid alternative with a 30-day trial before a license is required.

iboss Cloud is a paid alternative with custom pricing.

Verdict

Choose mitmproxy if you need free, configurable control over HTTP traffic, including editing, replay, and multiple proxy modes. Its interfaces and extensibility make it a strong toolkit for technical workflows. Look elsewhere if you need reliable HTTP/3 client replay or cannot accommodate regular updates to bundled binaries and Docker images.