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WebApp performance monitoring by performance.mark with metadata

I’ve created performance-mark-metadata. This library provide performance.mark with custom meta data.

This library inspired by User Timing API Level 3 proposal. This proposal will add details as metadata to performance.mark.

Currently, Performance.mark() API can not add metadata to marking.


Old browser need to Performance.mark() polyfill.


Install with npm:

npm install performance-mark-metadata
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Usage in Node.js

Node.js 8.5.0 introduce perf_hooks module. You can use this library by passing require("perf_hooks").performance to PerformanceMetadataMarker constructor arguments.


This example show actual usage.

You want to found performance problem on viewing the site. You can analyze the problem by using performance-mark-metadata.

It is useful for Real user monitoring(RUM). In development, you can use browser’s development tools, but it is difficult about RUM.

Mark points

  • Mark current Frame Per Seconds(FPS)
  • Mark each action like “onClick”

Record FPS

and record action

After that, you can get FPS and action logs.


You can get the log data and analyze the log data.

For example, visualize the log data by using C3.js.

You can found the relationship between “FPS” and “Heavy Task”. As a result, You can found that the performance problem is caused by “Heavy Task”.

Welcome to ⭐️ and Pull Request!

Top comments (2)

bgadrian profile image
Adrian B.G.

Can it be used to gather sample data from users and centralize it? Also can it be used w/o nodejs? For a static website for example.

azu profile image

Can it be used to gather sample data from users and centralize it?

Yes, But you should prepare own logging system and post data to the logging system.
For example, API Gateway + Lambda + S3(Post serialized JSON data from a browser to lambda via API Gateway, and save it to S3).

Also can it be used w/o nodejs?

Yes, It is work on modern browser.

Logging backend could be implemented in any language. It just treat log data like json.