For AI agents: the complete documentation index is available at /next/llms.txt, the full documentation bundle is available at /next/llms-full.txt, and this page is available as Markdown at /next/guide/devtool/trace.md.
Lynx
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  • Trace

    Trace is a performance analysis tool. With Trace, you can obtain a detailed rendering workflow of Lynx pages, making it easier to locate, analyze, and fix issues such as jank and long-running tasks.

    Core Capabilities of Trace

    1. Visualizing the Rendering Pipeline

    Trace provides a complete timeline view of the entire page process, detailing each stage: script execution, element construction, layout calculation, final rendering and others. With Trace, you can:

    • Clearly see the time distribution for each key stage (such as layout and painting);
    • Directly identify bottleneck nodes and performance issues;
    • Detect redundant or repeated rendering tasks to optimize page performance.

    This end-to-end visualization is especially valuable for page optimization and tuning complex page performance.

    Trace Render Pipeline

    2. Tracing Engine Execution

    Trace dives deep into the Engine and thoroughly records:

    • The sequence of task scheduling and queue switching
    • The full picture of event handling chains
    • Precise timing and relationships for API calls

    This information is useful for analyzing issues like asynchronous task congestion or event response delays.

    Trace Task Scheduling

    3. Rich Performance Analysis Tools

    Trace is a multidimensional performance analysis platform:

    • Element Analysis: Track changes in the Element tree structure, identify high-frequency or heavy node operations, and uncover performance risks in your page structure.
    Element
    • NativeModules Call Analysis: Monitor detailed NativeModules call processes, clearly display the timing and parameters of each NativeModule call, and pinpoint potential bottlenecks.
    NativeModules
    • Smoothness Analysis: Use flame charts of task durations to quickly locate the root causes of jank, helping you optimize animations and interactions.
    Trace Frame

    Next Steps

    Compatibility

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    Except as otherwise noted, this work is licensed under a Creative Commons Attribution 4.0 International License, and code samples are licensed under the Apache License 2.0.