WebSocket Visualizer

About

🔌 WebSocket Visualizer — WebSocket Connection Visualizer for Chrome DevTools

WebSocket Visualizer is a powerful developer extension that adds a new tab to Chrome DevTools, displaying all WebSocket messages passing through a page in real time. The extension helps analyze, filter, and understand interactions between the client and server over the WebSocket protocol—without changing application code or using third-party libraries.

🌐 Main Idea

Modern applications actively use WebSocket connections for real-time data exchange—chats, exchanges, games, financial panels, IoT devices, and other systems.
However, standard browser tools don't provide a convenient way to observe these data streams. WebSocket Visualizer solves this problem: it injects itself into the page context and intercepts native WebSocket events (open, message, close, error, send), visualizing everything in a separate DevTools tab—beautifully, structured, and interactively.

⚙️ Key Features

📡 Intercept All Connections

The extension automatically replaces the native WebSocket constructor, tracking all connections opened by a page or libraries (including Socket.io, ws, Primus, etc.)

💬 Message Display

Each incoming and outgoing message is displayed as a card with details:

Event time (in milliseconds)

Direction (⬇️ incoming / ⬆️ outgoing)

Event type (type, event, action, cmd — automatically detected)

Message content with JSON formatting

Connection URL and WebSocket session ID

🧠 Smart Grouping

Messages are grouped by event type (e.g., message, update, trade, heartbeat) — allowing you to quickly analyze the protocol structure and the frequency of specific events.

📈 Real-Time Statistics

The top panel displays a summary:

Active Connections

Total Messages

Sent and Received
All counters are updated in real time without reloading

🔍 Flexible Filtering

Quick search by event type or keywords

Direction switch: "All / Incoming / Outgoing"

Click on an event type in the sidebar to instantly apply a filter

⏸️ Pause and Resume

You can pause the event stream for analysis and resume it later without losing context—useful for heavy traffic or historical analysis.

🗑️ Clear and Reset

One button clears all messages and statistics, preserving active connections and filters.

🌍 Multilingual

Supported interface languages:

English 🇬🇧

Russian 🇷🇺

Ukrainian 🇺🇦

Deutsch 🇩🇪

Spanish 🇪🇸


The language choice is saved and applied automatically on next launch.

🎨 Modern Design

The interface is inspired by Visual Studio Code:

Dark theme

Soft gradients and highlighting of active elements

Smooth message animations

Stylized scrollbars and neat typography

🧭 Instructions for use

Open DevTools (F12 or Ctrl + Shift + I).

Go to the WebSocket tab—this is the extension interface.

Load or refresh the page where WebSocket connections are enabled.

The extension will automatically intercept and display all events:

🔗 connection — connection created

✅ open — connection opened

⬇️ incoming — incoming message

⬆️ outgoing — outgoing message

❌ close — connection closed

⚠️ error — error or failure

Use filters to focus on the events you need.

You can pause the stream with the ⏸️ Pause button, examine the data, and then continue with ▶️ Resume.

To clear the data, click 🗑️ Clear — the interface will refresh and begin waiting for new connections.

All actions are instantly reflected in the UI: animations, counters, and filters are synchronized in real time.

Examples of use cases

🔍 Debugging real-time chats and messengers

💸 Analysis of crypto exchange WebSocket APIs

🕹️ Monitoring game servers and network interactions

💬 Testing push notifications and streaming services

🧩 Analysis of non-standard protocols over WS

📊 Educational projects on working with real-time data

🔧 Additional features

Automatic JSON formatting with structure highlighting

Automatic scrolling to the last message

History limitation (up to 1000 messages per list) for performance optimization

Security and privacy

The extension does not collect, save, or send data from websites.

All operations are performed locally within the browser context.

Minimal permissions (activeTab, scripting, storage) are used exclusively for data visualization within DevTools.

No external requests, trackers, or third-party APIs.

🆕 New in 1.3.0

The new version of WebSocket Visualizer 1.3.0 adds support for German and Spanish, and the interface language switcher has been updated to include new localization options. Connection activity monitoring and state management have been improved, and a JSON viewer has been implemented for detailed viewing of message data. The interface has received visual improvements and new statistics elements: you can now monitor the number of bytes sent and received in real time.
Furthermore, message export capabilities have been expanded to include JSON, CSV, and HAR formats, and a button for copying individual messages has been added. All export and statistics-related text is now localized for all supported languages. These updates make WebSocket Visualizer even more convenient for analyzing traffic, testing, and debugging WebSocket connections directly in the browser.

🆕 New in 1.4.0

WebSocket Visualizer now supports binary data handling with an integrated hex viewer for deeper inspection of raw message content. The message parsing logic has been improved to ensure more accurate decoding of complex WebSocket frames. Additionally, this update introduces localized translations for all new binary data features, providing a smoother experience for users in multiple languages.