User Timing marks and measures
"User Timing marks and measures" essentially means that your webpage isn't using the User Timing API, which can provide valuable insights into the performance of your site.
How to fix it
The solution is to use the User Timing API to add marks and measures to your code. Here's how:
Step 1: Identify Opportunities for User Timing
First, you need to identify where in your code you could benefit from User Timing. This might be at the start and end of operations that you want to measure, or at points in your code that you want to mark for later reference.
Step 2: Add User Timing Marks and Measures
Once you've identified where to add User Timing, you can add marks and measures using the performance.mark() and performance.measure() methods.
// Add a mark at the start of an operation
performance.mark('startOperation');
// ...perform the operation...
// Add a mark at the end of the operation
performance.mark('endOperation');
// Measure the time between the start and end marks
performance.measure('operationTime', 'startOperation', 'endOperation');
In this example, we've added marks at the start and end of an operation, and measured the time between them.
Step 3: Analyze Your User Timing Data
For an even better solution, consider analyzing your User Timing data to identify performance bottlenecks and opportunities for optimization. You can view your User Timing data in Chrome DevTools under the 'Performance' tab.
By using the User Timing API, you can gain valuable insights into the performance of your site.