---
breadcrumbs:
- - /for-testers
  - For Testers
page_name: providing-network-details
title: How to capture a NetLog dump
---

A *NetLog dump* is a log file of the browser's network-level events and state.
You may be asked to provide this log when experiencing page load or performance
problems.

***Note:** if you want to take a netlog for **Android WebView**, [read this
guide](https://chromium.googlesource.com/chromium/src/+/HEAD/android_webview/docs/net-debugging.md)
instead.*

To create a *NetLog dump*, open a new tab and navigate to:

> chrome://net-export/

[<img alt="image" src="/for-testers/providing-network-details/net-export-61.png"
height=321 width=400>](/for-testers/providing-network-details/net-export-61.png)

You can then follow the instructions on that page.

**Step-by-step guide**

1.  Open a new tab and go to chrome://net-export/
2.  Click the **Start Logging To Disk** button.
3.  Reproduce the network problem **in a different tab** (the
            chrome://net-export/ tab needs to stay open or logging will
            automatically stop.)
4.  Click **Stop Logging** button.
5.  Provide the resulting log file to the bug investigator.
    *   Either attach the file to your existing or [new bug
                report](https://issues.chromium.org/new), or send email to the bug
                investigator.
    *   Provide the **entire** log file. Snippets are rarely sufficient
                to diagnose problems.
    *   **Include any relevant URLs or details to focus on.**

> **PRIVACY**: When attaching log files to bug reports, note that Chrome bug
> reports are **publicly visible** by default. If you would prefer it be only
> visible to Google employees, mention this on the bug and wait for a Google
> engineer to restrict visibility of the bug before you attach the file.

**Advanced: Byte-level captures**

By default, NetLog dumps do not include all of the raw bytes (encrypted or
otherwise) that were transmitted over the network.

To include this data in the log file, select the **Include raw bytes** option at
the bottom of the chrome://net-export/ page:

> **PRIVACY:** Captures with this level of detail may include personal
> information and should generally be emailed rather than posted on public
> forums or public bugs.

[<img alt="image"
src="/for-testers/providing-network-details/net-export-raw-bytes-61.png"
height=108
width=400>](/for-testers/providing-network-details/net-export-raw-bytes-61.png)

**Advanced: Logging on startup**

If the problem that you want to log happens very early and you cannot start
chrome://net-export in time, you can add a command line argument to Chrome that
will start logging to a file from startup:

> --log-net-log=C:\\some_path\\some_file_name.json

If a granularity for capture other than the default of "Strip private
information" is needed, one of the following flags can be used:

*   --net-log-capture-mode=IncludeSensitive
*   --net-log-capture-mode=Everything

(As of M117) You can limit the maximum size of the log file using
`--net-log-max-size-mb` and specify the max size in megabytes. For example,
the following will limit the max log size to 100 MB:

*   --net-log-max-size-mb=100

(As of M137) Automatically stop logging after a fixed duration. You can stop logging
after *N* seconds and flush the NetLog file to disk by supplying:

*   --net-log-duration=&lt;seconds&gt;

For info about adding command line options, see
[command-line-flags](/developers/how-tos/run-chromium-with-flags).

**Advanced: Viewing the NetLog dump file**

The log file can be loaded using the
[netlog_viewer](https://chromium.googlesource.com/catapult/+/HEAD/netlog_viewer/).