Learn how to check real user data from Chrome User Experience Report (CrUX) without the need to install a monitoring script.

Track real user Core Web Vitals data with CrUX Dashboard

A yearly summary of new features we released, product improvements we’ve made and what’s coming in the future.

A Year in Features: What We Released in 2023

Is it possible to define human perception with a handful of metrics? Learn how people comprehend time, and use this knowledge to make even longer waits feel less frustrating.

Psychology of Speed: A Guide to Perceived Performance

Learn how to quickly check Web Vitals assessment, request priority, asset breakdown and JavaScript execution.

Easily investigate page performance with Snapshot Overview

Find out how Pull Request Reviews can help your team collaborate and avoid releasing performance regressions.

Test Speed in CI/CD and Pull Requests

A fast and resilient content delivery network is one of the best ways to improve the performance of your site. Here’s how to make an informed decision when choosing one.

What is a CDN? An Unbiased Guide to Content Delivery Networks

TTFB is the backbone of page speed: it can make or break the experience of your sites. Learn how to test and  track it.

Time to First Byte: What it is and How to Make Improvements

Slow websites don’t become fast because of one-off tactics. To accomplish strong Core Web Vitals metrics, companies need to establish an organisation-wide foundation that produces faster pages.

5 Best Practices to Sustainably Improve Core Web Vitals

If the Internet is to be a place for good, we all need to confront what it’s become.

The Calm Web: A Solution to Our Scary and Divisive Online World

Image optimisation is the web performance the lowest hanging fruit. Learn how to optimise imagery without sacrificing its quality.

The Ultimate Guide to Image Optimisation

Page responsiveness is critical to a good user experience on the web. Learn to measure and improve it with a new metric: Interaction to Next Paint.

Interaction to Next Paint (INP): What is it and How to Improve It

Anyone can positively contribute to improving web performance. If you’re unsure where to start, try these beginner-friendly strategies!

5 Beginner Website Speed Optimisations and How to Do Them Right

The current wait-and-see speed strategy isn’t best for your business. The best day to start thinking about web performance is today.

Your Web Performance is Too Reactive; It’s Time to Do More Than Put Out Fires

The most successful teams are the highly collaborative ones. Here’s how we optimise Pull Request authoring and reviews to create an environment where everyone can contribute.

5 Ways to Streamline the Pull Request Review Process

You’ll always need good content to rank well and bring in new readers. User experience and speed is what’ll make them stay.

SEO Content Has Peaked; it’s Time to Focus on Performance

With near-limitless number of ways you could measure web performance, are you choosing the most reliable metrics?

7 Website Performance Metrics to Track for Better UX

Everyone can improve performance. Choose from a range of basic to advanced solutions to the most common speed issues.

8 Causes of Slow Website Loading (And How To Fix Them)

Learn about the unique advantages of synthetic monitoring and how you can use them to improve your site performance.

What is Synthetic Monitoring and How to Get More From It

Deciding between free, in-house, or paid tools is never easy. Here’s how to make an informed decision about web performance monitoring tools and what features are vital to success.

7 Unexpected Benefits of Web Performance Management Software

Until you set specific goals, it’s not clear what metric you want to improve, how you’ll do it, and who’s in charge of getting it there. Learn how to set performance budgets to meet and maintain your speed goals.

Performance Budgets: The Easiest Way to a Faster Site

Any delay longer than 50 milliseconds and visitors sense that a page is unresponsive. Tracking and reducing your page’s Total Blocking Time is vital to avoiding a poor user experience.

Total Blocking Time: A Short and Sweet Guide for Happier Users

Optimising Largest Contentful Paint has an outsized impact on when most critical content appears. These four proven methods will help you find and correct performance issues holding your page back.

How To Improve Largest Contentful Paint for Faster Load Times

Priority Hints: Influence How Browsers Fetch Resources

Here’s a yearly summary of new Calibre features, product improvements and upcoming releases.

A Year in Features: What We Released in 2021

Why Lighthouse Performance Score Doesn’t Work

Next.js Performance: Making a Fast Framework Even Faster

Create custom workflows with your favourite apps, no coding required.

Connect Calibre to thousands of apps with Zapier

Everything You Have to Know About Core Web Vitals

See if poor web performance impacts user experience and your website ranking.

Check If Your Site Passes Core Web Vitals Assessment

Reliable and good services can help your team build a better product. Here are our favourites.

What We Use to Build Calibre

Analyze and fix JavaScript bundle performance issues with developer tools and strategies.

Small Bundles, Fast Pages: What To Do With Too Much JavaScript

How we switched to a 32 hour work week without compromising productivity.

Four Day Work Week: How and Why We Work Less

View, share and set up reporting in a way that works best for your company.

Collaborate on Speed with Teams

How Lighthouse 8 Changes Affect Your Metrics

We explain what it means to us to be a sustainable company that cares about the people it impacts.

Why We Run a People First Company

Reduce frustration and content shifts by monitoring the Core Web Vital metric.

Cumulative Layout Shift: Measure and Avoid Visual Instability

Learn how to implement request prioritisation to significantly improve speed.

The Critical Request: How to Prioritise Requests to Improve Speed

How to Convince Your Boss to Care About Speed

How to Plan and Deliver on Site Speed as a Team

Learn the most common speed issues caused by CSS and how to avoid them.

How to Improve CSS Performance

95% customer satisfaction rating with no support team. How do we do it?

How We Deliver Great Customer Experience Without a Support Team

Site Speed and Search Ranking (Complete Guide)

Learn how to write an effective job posting that respects candidates.

How to Write a Job Ad (That People Actually Want to Apply For)

Release Notes is a monthly summary of new Calibre features, product improvements and upcoming releases.

A Year in Features: What We Released in 2020

Compress Your Images in GitHub with Image Actions 2.0

Find Slow Pages Easily and Benchmark Against the Competition

Set and Meet Speed Budgets

5 Common Mistakes Teams Make When Tracking Performance

Why You Might Want to Reconsider Tracking First Meaningful Paint

Performance During a Pandemic

See Performance Issues Before They Reach Your Customers

The New Generation of Performance Metrics for Better User Experience

Performance for Designers Part 1: Typography

Learn critical web performance concepts and strategies in this straight-forward primer

Getting Started with Web Performance

Learn about the high user experience cost of live chat tools and how to implement them without compromising speed.

How We Improved the Performance of Our Live Chat by 30%

Learn how to keep your animations buttery smooth at 60 fps in this detailed guide to exploring animation performance using Chrome DevTools.

Investigate Animation Performance with DevTools

Automatically Compress Images on Pull Requests

Everything you need to know to improve page speed

How Google Pagespeed Works: Improve Your Score

Everything you need to know about Time to Interactive

Time to Interactive: Focusing on the Human-Centric Metrics

Learn how to uncover React performance issues with a step-by-step walkthrough of Chrome devtools performance profiler

Profiling React component performance with Chrome devtools

Learn how real-world web performance looks beyond the bubble of privilege.

Welcome to our page speed knowledge base 👋🏻

Product

Track real user Core Web Vitals data with CrUX Dashboard

Latest Articles

Product

A Year in Features: What We Released in 2023

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Core Web Vitals

Interaction to Next Paint (INP): What is it and How to Improve It

How To Improve Largest Contentful Paint for Faster Load Times

Cumulative Layout Shift: Measure and Avoid Visual Instability

Web Performance Strategy

How to Convince Your Boss to Care About Speed

How to Plan and Deliver on Site Speed as a Team

Your Web Performance is Too Reactive; It’s Time to Do More Than Put Out Fires

One platform for all web performance needs