Troubleshoot Chrome browser performance issues

Write down the events that reduce Chrome browser performance.

• Do you experience reduced Chrome browser performance as soon as you start the browser?
• Does the Chrome browser run slower when you load more than one webpage? If so, how many webpages?
• Was the browser running continuously for a few days? If so, for how long?
• Do you run Chrome browser in a shared environment, such as Microsoft Windows Remote Desktop Services, Citrix XenApp, Citrix XenDesktop, or VMWare Horizon?
• In a shared environment, does browser performance depend on the number of users running Chrome browser at the same time?

Use Windows Task Manager or another process manager, such as Process Explorer, to identify processes with high CPU usage.

Determine the type of process that makes Chrome browser run slower. In Process Explorer, you can see command-line parameters to verify the type of Chrome browser process that’s running. For example, the --type=renderer process is responsible for one or more tabs or extensions that are currently in use. If you don’t see the --type parameter, the process is responsible for all disk and network access and user interactions.

Common scenarios that reduce browser performance include:

• The main process slows down if disk access is slow or there’s not enough system memory available.
• CPU usage for the renderer process increases if you run web apps that aren’t well programmed. Isolate Chrome browser tabs and identify which web apps or webpages are reducing browser performance.
• The graphics processing unit (GPU) process slows down if there’s an issue with a particular graphics card driver. Or, Chrome browser is rendering a graphics-intensive page, such as a website with 3D images or YouTube videos.

If you can’t identify the process that’s causing high CPU usage with a process manager, try recording performance event traces and sharing them with Chrome engineers. Event Tracing for Windows (ETW) collects performance information from all running processes during a specified time period. Traces might contain sensitive data, such as process names or parameters and DLL function names or filenames. You can securely share your trace with Chrome engineers by following the instructions below.

Step 1: Download the tool

You can use the open-sourced application UIforETW to record the trace files.

Note: The names of all files that are read or written during the trace will be included in the trace file. Also, anonymized input data is recorded. To protect sensitive data, all letters are replaced with A and all numbers are replaced with 1.

1. Go to the GitHub project page and download the latest release of UIforETW. It will have a name similar to etwpackage1.49.zip.
2. Extract the contents and run etwpackage\bin\UIforETW.exe to install the necessary versions of the Windows Performance Toolkit. 
3. Wait for the installations to finish.

Step 2: Record ETW traces

1. On your local Windows machine, open UIforETW.
   1. Note: We recommend you turn on these extra options in UIforETW before capturing a trace. In settings, select these Chrome tracing categories: "input, toplevel, latency, blink.user_timing, disable-by-default-toplevel.flow". While investigating your issue, we may ask you to collect another trace with different categories selected.
2. Click Start Tracing. The tool starts recording the last 10–60 seconds of activity. You can leave the tool running indefinitely because it only records the last 60 seconds (approximately) of activity. The actual duration depends on system-activity levels.
3. When you’ve reproduced the slowdown, enter Ctrl+Win+R to save the trace buffers to the file.
4. In the Trace information field, enter a description of the problem and where in the trace it occured. Include as much detail as possible, especially what the problem was and user input around the time of the problem.
5. Right-click the list of traces and select Browse folder to open the documents\etwtraces folder, which contains the traces. There will be a .etl file and a .txt file for each trace.

Step 3: Share your trace file with Chrome engineers

1. Upload the .etl and .txt trace files to Google Drive. Learn more about Google Drive.

   Note: Don’t share the file yet.

2. Create a new Chromium bug and paste the link to the Google Drive trace file in the bug.
3. When Chrome engineers request access to the trace file, share the file in Google Drive.

   Important: Only share the trace file with email addresses ending with @google.com or @chromium.org. For added security, add a comment in the Chromium bug asking for contact information before you share the file. For more information about UIforETW, see this instructional video.