n0qlog

A high-performance, native GUI application for viewing and analyzing QUIC qlog files.

Built with egui and designed to be faster than web-based tools like qvis. Efficiently handles large qlog files.

Installation

cargo install n0qlog

Or build from source:

cargo build --release

macOS Gatekeeper

Downloaded binaries may be blocked by Gatekeeper. To allow:

xattr -cr /path/to/n0qlog

Usage

Running the Application

n0qlog

Or with cargo:

cargo run --release

Loading Files

1. Click File → Open...
2. Select a .qlog, .json, or .sqlog file
3. Supports standard JSON, NDJSON, and RFC 7464 JSON-SEQ formats

Views

Switch between views using the View menu:

• Event List - Browseable table of all events with filtering
• Sequence Diagram - Timeline showing packet exchanges between client/server
• Congestion Graph - RTT and congestion window metrics over time
• Packetization Diagram - Frame and packet boundary visualization

Filtering

In Event List view, filter by:

• Event name (e.g., "packet_sent", "metrics")
• Stream ID
• Packet type (Initial, Handshake, 0-RTT, 1-RTT)

Interactive Features

• Zoom/Pan: Scroll wheel to zoom, drag to pan
• Click to Select: Click events or packets to see details
• Toggle Metrics: Show/hide individual metrics in graphs

Features

• Multi-format support (JSON, NDJSON, JSON-SEQ)
• SIMD-accelerated parsing with sonic-rs
• Virtual scrolling for large event lists
• Interactive diagrams with zoom/pan
• Event detail panel with full JSON view

License

Apache-2.0 OR MIT