New Fluxzy v2 just shipped. Electron is out, Tauri is in. gRPC ready, 3x smaller install. Learn more
Offline HTTP Debugger, No Subscription

Debug anything that speaks HTTP.

Wire-level capture for every modern protocol. REST, OAuth, gRPC, LLM streams, fully decoded and ready for breakpoints, mocking, and replay.

All platforms | CLI | Docker | GitHub
Fluxzy Desktop Overview

Explore Features

Comprehensive Rules

Rewrite reality. 50+ actions, mock responses, spoof DNS, throttle bandwidth, fake auth. Edit visually or dive into YAML.

Launch Applications

Skip the system proxy dance. Launch Chrome, Firefox, or any app directly, already hooked and ready to intercept. Zero config.

Live Debugging

Pause traffic at any stage, DNS lookup, before request, after headers. Step through the network like stepping through code.

Capture OS Traffic

One click, and Fluxzy becomes your system proxy. Every HTTP request from every app flows through, no manual browser config needed.

With Raw Capture

PCAP recording is live. Every packet gets saved, not just HTTP, the whole conversation. Wireshark-ready, no extra tools.

Search Everywhere

Ctrl+T your way through Fluxzy. Jump to filters, rules, settings, exchanges, anything. Type what you need and you're there.

Filter Toolbar

Find anything, fast. Ctrl+click to stack filters with AND, Shift+click for OR. Ctrl+Shift live debugs the next matching request. Create and save filter.

Enhanced Response Viewer

Full Monaco editor for your response body. Syntax highlighting, code folding, search, the same editor powering VS Code.

Diff tool

Select two exchanges, hit diff. Headers, body, cookies—everything side by side, changes highlighted. Find what broke between "it worked yesterday" and "it's broken now" in seconds.

Fluxzy Desktop Overview

What Makes Fluxzy Different

Six reasons developers switch from Fiddler and Charles

Open source engine

The interception engine behind Fluxzy is fully open source. Every cryptographic decision, every stream transformation: auditable and extensible. No black box proxying your traffic.

github.com/haga-rak/fluxzy.core

Yours. Offline. Forever.

No account required. No cloud sync. No "sign in to continue." Fluxzy is good old-fashioned desktop software that works without an internet connection. Your traffic data stays on your machine, period.

Download Fluxzy

Built on Tauri, not Electron

Native performance, fraction of the memory footprint. Opens large archive files without choking. Fluxzy won't eat your RAM for breakfast.

Explore features

Debug gRPC like regular HTTP

Inspect and modify gRPC calls with the same workflow you use for REST. Bring your own proto files for decoded, human-readable views.

gRPC debugging guide

Deep protocol coverage

Two TLS engines (system default or BouncyCastle). Raw PCAPNG capture with embedded SSL keys. HTTP/1.1, HTTP/2, WebSocket, SOCKS5, all first-class.

See all protocols

Full debugging toolkit

Breakpoints, live editing, response mocking, request replay, DNS spoofing, bandwidth throttling, 75k+ req/s throughput. Plus a YAML-based rule engine with 100+ built-in filters and actions for codeless traffic alteration.

Breakpoints & live edit
View All Features

Built for modern HTTP debugging

JWTs decoded, LLM streams parsed, gRPC frames structured, rules nested as deep as you need.

Decoders

Decoded views for modern payloads

Fluxzy reads what flows over the wire. JWTs are split into header, payload and signature with algorithm and expiry exposed. LLM API calls (OpenAI, Anthropic, Gemini) are decoded into model, tool calls, tool choices, token usage and prompts. gRPC frames are unwrapped into typed messages. Response bodies open in a Monaco editor (the same engine that powers VS Code), with syntax highlighting, code folding and search.

Intercept gRPC sessions
Fluxzy Desktop decoding a JWT token: header, payload, signature, algorithm and expiry
Rules

Composable rules, nested as deep as you need

Every part of an exchange can be transformed: request line, headers, body, TLS fingerprint, DNS resolution, upstream proxy, bandwidth. 50+ built-in actions and 50+ filters combine with nested AND/OR groups, so a single rule can target POST /v1/chat/completions on api.openai.com while excluding gRPC traffic.

Browse all directives
Fluxzy Desktop nested filter collection combining multiple filters with AND and OR operators
Hooks

Launch apps already hooked

Skip the system-proxy dance. Fluxzy detects installed browsers (Chrome, Firefox, Brave, Edge) and shells (PowerShell, cmd, macOS Terminal, GNOME Terminal, Ptyxis) and launches them already routed through the capture session. For everything else, generate a bootstrap script that exports the right environment variables for Node, Python, Ruby, Go, Rust, .NET, package managers and Git.

All capture features
Fluxzy Desktop Launch Applications panel: Chrome, Firefox and Terminal launched with proxy active, plus a bootstrap shell script generator
Search

Search everywhere with Ctrl+T

One palette across the whole app. Type a host, an action, a filter, an exchange ID or a setting, and Fluxzy ranks every match and jumps you there. The same shortcut that fuzzy-finds an action opens global DNS-over-HTTPS settings or filters the grid to 5xx in two keystrokes.

Fluxzy Desktop command palette showing filter, launch and search results across the application
Debug

Live-edit and breakpoints

Pause traffic at DNS lookup, before request, after headers or on response. Edit URL, method, headers and body in place. Resume one step at a time, or all at once. The same workflow as stepping through code, applied to the network.

Breakpoints & live edit
Fluxzy Desktop live-edit dialog paused on a response with editable headers and body
Export

Export to anything that speaks HTTP

One click out: HAR for browser tooling, SAZ for Fiddler users, raw PCAPNG with embedded SSL keys for Wireshark, cURL commands (cmd, bash, with proxy) and .http scratch files for VS Code and JetBrains REST clients.

Fluxzy Desktop exporting a request as a full bash cURL command with headers preserved

Free and unlimited. Fluxzy Desktop Community Edition. No card, no cloud.

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New

Capture from your Android phone

Fluxzy Connect brings the same wire-level HTTP debugging to Android. Inspect any app's traffic from your phone, with the rules and decoders you already know from the desktop.

Read the introduction Get it on Google Play

Everything you'd expect, baked in

A complete HTTP toolkit out of the box. No paid tier, no plugin store, no telemetry.

Capture & decode

Find anything

Mock & redirect

Modify in flight

Network & TLS

Beyond the desktop

Browse every filter and action

Integrate with Your .NET App

Access all Fluxzy features — from request recording to advanced traffic alteration — in your own code with the open-source Fluxzy NuGet packages.

NuGet Packages Documentation Source Code

Ready to Debug Smarter?

Download Fluxzy for free and start capturing, analyzing, and modifying HTTP traffic in minutes.

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