netlog-viewer

netlog-viewer is a Visual Studio Code extension for viewing net-export (NetLog) logs captured from Chromium-based browsers.

Table of Contents

• netlog-viewer
  • Table of Contents
  • Features
  • Requirements
  • Installation
    • From the Visual Studio Code Marketplace
    • From a VSIX file
  • Usage
  • Supported Files
  • Commands
  • Settings
  • Limitations
  • Roadmap
  • Contributing
  • Sponsors
  • License

Features

• NetLog log viewer: View .json logs captured with net-export in a custom editor inside VS Code.
• 14-tab layout:
  • Import — Export date and time, capture mode, browser/OS information, command line, and user comments.
  • Events — A list of events grouped by source, with filtering (type: / id: / is:active|error / sort:), selection, and event trace details (t= / st= / [dt=]).
  • Timeline — Time-series data such as socket count, request count, and bytes transferred, rendered on a canvas (scroll to zoom, drag to pan).
  • Proxy / DNS / Sockets / StreamPool / Alt-Svc / HTTP/2 / QUIC / Reporting / Cache / Modules / Prerender — Status tables for each subsystem.
• Read-only and fully offline: Never writes to files and never communicates over the network.
• No external runtime libraries: Both the parser and the viewer are built entirely from scratch using only the standard library (see DEVELOPMENT.md for details).
• Supports .json / .netlog / .gz (gzip).

Requirements

• Visual Studio Code 1.90.0 or later
• No additional runtimes or external applications required

Installation

From the Visual Studio Code Marketplace

1. Open the Extensions view from the VS Code sidebar (Ctrl+Shift+X / ⌘+Shift+X).
2. Search for Netlog Viewer.
3. Click Install.

From a VSIX file

code --install-extension netlog-viewer-<version>.vsix

Alternatively, run "Extensions: Install from VSIX..." from the Command Palette (Ctrl+Shift+P / ⌘+Shift+P) and select the .vsix file.

Usage

1. Capture a log in a Chromium-based browser.
   • Chrome: chrome://net-export/, Microsoft Edge: edge://net-export/
   • Click Start Logging To Disk, choose a destination .json file, reproduce the issue, and then click Stop Logging.
2. Open the captured .json file in VS Code.
   • If the file name matches one of the supported file patterns, it opens automatically in Netlog Viewer.
   • To open a .json file that does not match, right-click the file in the Explorer and choose "Open With…" → Netlog Viewer, or run the "Netlog Viewer: Open File" command.
3. Switch between the tabs on the left to inspect the state of each subsystem. On the Events tab, type a filter to narrow down sources, and select a row to display the event trace in the right pane.

Supported Files

The custom editor automatically associates with the following file name patterns (it does not take over every .json file indiscriminately):

• *.netlog
• *.netlog.json (and *.netlog.json.gz)
• *net-export*.json (and *net-export*.json.gz)
• *net_log*.json
• *netlog*.json

.gz (gzip-compressed) files are decompressed automatically. Files that do not match the patterns above can be opened with the "Netlog Viewer: Open File" command.

Commands

The following command is available from the Command Palette (Ctrl+Shift+P / ⌘+Shift+P).

Settings

There are currently no user-configurable settings. Options such as rendering limits and the default tab are being considered in the Roadmap.

Limitations

• For viewing exported logs only. Real-time connection to and capture from a live browser (as with net-internals) is not supported. (The information tabs display the polledData included in the log, and tabs with no data are hidden automatically.)
• The only supported compression format is gzip (.gz); .zip is not supported.
• Some information tabs (Proxy settings / DNS settings / Reporting clients and NEL) currently display formatted JSON.
• Because it is read-only, logs cannot be edited or saved.

Roadmap

• [ ] User settings (rendering limits, default tab, etc.)
• [ ] Virtualization and progressive rendering for large logs
• [ ] More detailed formatting of information tabs and links to event sources
• [ ] Support for the .zip format

Contributing

For specifications and design as well as build/debug instructions, see DEVELOPMENT.md. For publishing to the Marketplace, see PUBLISHING.md.

Sponsors

If you would like to support the development of this project, contributions via GitHub Sponsors are warmly welcomed. Your support will be used to improve features and maintain the project over time.

License

This project is released under the MIT License.