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What are the best metrics for Frontend Development?

Published 3 months ago

The plan aims to enhance frontend development by focusing on several critical performance metrics. Page Load Time, for instance, measures how quickly a web page becomes fully operational for the user. Achieving the benchmark of 2 to 3 seconds enhances user experience and retention.

An important metric here is Time to First Byte (TTFB), which ensures that servers respond quickly, ideally within 200 milliseconds. Faster server response times contribute to quicker page loads. First Contentful Paint (FCP) is another vital metric, focusing on how soon visible content appears on the user's screen, with a target of less than 1.8 seconds, making the site feel more responsive.

JavaScript Error Rate measures the percentage of user sessions encountering errors, aiming for less than 1%. Reducing this rate improves overall site stability and user trust. Lastly, the User Satisfaction (Apdex) Score quantifies user satisfaction with site performance, striving for a score of 0.8 or higher. Meeting these metrics is crucial for enhancing the overall user experience and maintaining site reliability.

Top 5 metrics for Frontend Development

1. Page Load Time

The time it takes for a web page to fully load from the moment the user requests it

What good looks like for this metric: 2 to 3 seconds

How to improve this metric:
  • Optimise images and use proper formats
  • Minimise CSS and JavaScript files
  • Enable browser caching
  • Use Content Delivery Networks (CDNs)
  • Reduce server response time

2. Time to First Byte (TTFB)

The time it takes for the user's browser to receive the first byte of page content from the server

What good looks like for this metric: Less than 200 milliseconds

How to improve this metric:
  • Use faster hosting
  • Optimise server configurations
  • Use a CDN
  • Minimise server workloads with caching
  • Reduce DNS lookup times

3. First Contentful Paint (FCP)

The time from when the page starts loading to when any part of the page's content is rendered on the screen

What good looks like for this metric: Less than 1.8 seconds

How to improve this metric:
  • Defer non-critical JavaScript
  • Reduce the size of render-blocking resources
  • Prioritise visible content
  • Optimise fonts and text rendering
  • Minimise main-thread work

4. JavaScript Error Rate

The percentage of user sessions that encounter JavaScript errors on the site

What good looks like for this metric: Less than 1%

How to improve this metric:
  • Thoroughly test code before deployment
  • Use error tracking tools
  • Handle exceptions properly in the code
  • Keep third-party scripts updated
  • Perform regular code reviews

5. User Satisfaction (Apdex) Score

A metric that measures user satisfaction based on response times, calculated as the ratio of satisfactory response times to total response times

What good looks like for this metric: 0.8 or higher

How to improve this metric:
  • Monitor and analyse performance regularly
  • Focus on optimising high-traffic pages
  • Implement user feedback mechanisms
  • Ensure responsive design principles are followed
  • Prioritise backend performance improvement

How to track Frontend Development metrics

It's one thing to have a plan, it's another to stick to it. We hope that the examples above will help you get started with your own strategy, but we also know that it's easy to get lost in the day-to-day effort.

That's why we built Tability: to help you track your progress, keep your team aligned, and make sure you're always moving in the right direction.

Tability Insights Dashboard

Give it a try and see how it can help you bring accountability to your metrics.

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