Overview

Fluxzy records and analyzes HTTP/1.1, HTTP/2, and WebSocket traffic over plain or secure channels, and can alter requests and responses. A standout is proxyless capture: it can record app traffic without proxy configuration, including from apps that ignore system proxy settings. That helps with stubborn clients, though iOS capture instead routes apps to the proxy.

It works offline without an account or cloud sync, and Fluxzy says it has no telemetry. Fluxzy.Core is GPLv3 open source, but Fluxzy Desktop is closed source. Published checksums, Authenticode signing for Windows binaries, and Apple signing and notarization for macOS builds offer useful download-integrity assurances.

Key features

Rules cover request and response editing, authentication injection, network slowdown simulation, request forwarding, DNS spoofing, TLS fingerprint changes, and HTTP-version forcing. Breakpoint rules, traffic replay, response mocking, and proxy chaining make it useful for reproducing and isolating application behavior, not just observing it.

Fluxzy decodes gRPC and Protobuf traffic either without a schema or with real field names from .proto files. It also captures OpenAI, Anthropic, and Google Gemini API requests and responses, including streaming and tool calls—useful for teams debugging both conventional services and LLM integrations.

Captures export to HAR, Fiddler SAZ, PCAPNG for Wireshark, cURL commands, .http files, and Fluxzy’s .fxzy format. Official NuGet packages expose the engine to .NET Standard 2.1, .NET 6, and .NET 8 applications. Fluxzy Connect captures Android traffic through a local VPN; iOS apps can be routed through the proxy.

Pricing

The Community Edition is 0.00 EUR per free and includes all features, but is limited to personal use and adds an x-fluxzy-community header. That makes it useful for individual evaluation, not unrestricted professional or team use. There is no free trial; the free edition provides a way to try the full feature set within its license terms.

Pro (Perpetual) costs 49.00 EUR per once, billed “Pay once, own forever.” It covers one developer, removes the personal-use restriction and header, and supports Windows, macOS, and Linux. It is the straightforward choice for a single developer who wants a permanent work license.

Enterprise (Perpetual) costs 59.00 EUR per once, with a minimum of 3 seats. The per-seat price is €59 for 1–9 seats, €49 for 10–49, and €39 for 50 or more. It fits teams that need multiple licensed seats; the minimum makes it unsuitable for a two-person purchase. Fluxzy offers a full refund if contacted within 14 days of purchase.

Platforms

Fluxzy lists Android, iOS, Linux, macOS, self-hosted, Windows, and API support. Desktop licenses explicitly cover Windows, macOS, and Linux; mobile capture is handled through Fluxzy Connect on Android or proxy routing on iOS.

Who it's for

Fluxzy is a strong fit for developers and security engineers who need to inspect or manipulate traffic from difficult-to-proxy apps, decode gRPC, or examine streaming LLM calls. Its offline operation and lack of cloud sync also suit workflows that favor local capture. Teams should account for the Enterprise minimum, while anyone needing an open-source desktop application should look elsewhere: only the core is open source.

Pros and cons

Pros: Proxyless capture reaches apps that ignore proxy settings, reducing setup friction for difficult clients.
Pros: gRPC decoding, LLM stream inspection, replay, mocking, and extensive export formats support debugging beyond basic HTTP browsing.
Pros: Perpetual paid licenses avoid recurring subscription charges, and the single-developer Pro plan has no team minimum.
Cons: The free edition is personal-use only and adds a branded header, so it cannot serve as an unrestricted work license.
Cons: Enterprise requires at least three seats, an awkward threshold for small teams.
Cons: The desktop application is proprietary even though Fluxzy.Core is GPLv3 open source.

Alternatives

For a broader comparison, browse Web Debugging Proxies. Choose NetworkSpy if its free plan’s limited LLM token-stream analysis, breakpoints, resource mapping, custom viewer builder, and scripting match your needs, or if you want a free trial. Reqable is worth considering when its Community plan’s one-device, 100MB storage, and three-rule limits suffice, or when its Premium annual plan fits better.

HTTP Toolkit offers a free Hobbyist plan for basic interception and inspection, manual breakpoints, and built-in HTTP client tools. mitmproxy is a free, open-source interactive HTTPS proxy for readers who prioritize an open-source option. HTTPeep is another alternative.

Fiddler Everywhere, Proxyman, and Requestly are also alternatives to consider.

Verdict

Choose Fluxzy if you need detailed local traffic capture and modification, particularly proxyless capture, gRPC decoding, or LLM API inspection, and want a perpetual license. Look elsewhere if your team needs a fully open-source desktop tool, or if the Community license’s personal-use terms and Enterprise’s three-seat floor do not fit.

	Fluxzy	Sniper
Free plan	Yes	No
Free trial	No	No
Paid from	Free	—
Open source	No	No
Platforms	Android, api, iOS, Linux, macOS, self-hosted, Windows	macOS, Windows
Free plan	Yes	—
Request/response editing	Yes	Yes
Breakpoint rules	Yes	—
Traffic replay	Yes	Yes
Response mocking	Yes	—
WebSocket inspection	Yes	Yes
Proxy chaining	Yes	—

Fluxzy vs Sniper

Fluxzy

Sniper