⚡️ 65: Use modern JavaScript for speed

        30 December 2020

⚡️ 65: Use modern JavaScript for speed

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[issue 65]()

#### Editor’s note

Here we are, the last issue of Performance Newsletter of 2020. This past year, we switched from monthly to every two weeks schedule to share the most recent and significant developments at the intersection of performance, accessibility and user experience. **We have sent 25 issues with over 150 tools, articles, case studies and tips to improve speed.**

This wouldn’t have been possible without the vibrant community of people (that includes *you*), committed to enhancing user experience and lowering entry barriers for using the web. No matter where you (or your team) is in their performance journey, keeping up-to-date with speed news is also a step towards a more accessible web. Who knows when you’ll be utilising one of the tools or strategies mentioned here.

If you have any feedback, questions, suggestions about Performance Newsletter, we’re all ears. Respond to this email or [drop us a line](mailto:[email protected]). We will keep working on making this email the most high-quality resource.

Thank you and see you in 2021!

Karolina & Team Calibre

#### What’s Performance newsletter?

Performance Newsletter is a fortnightly mailing by [Calibre](https://calibreapp.com), featuring web performance tools, talks and resources.

Don’t worry—we don’t spam. If you’d like to leave, [unsubscribe]() at any time. Suggest content [here](mailto:[email protected]).

# Articles

### [The Import On Interaction Pattern](https://addyosmani.com/blog/import-on-interaction/)

[Addy Osmani](https://twitter.com/addyosmani)

Using UI facades is one way of deferring or entirely removing the negative impact of third party JavaScript. Learn how to delay the loading of non-critical resources.

### [Maximally optimizing image loading for the web in 2021](https://www.industrialempathy.com/posts/image-optimizations/)

[Malte Ubl](https://twitter.com/cramforce)

A comprehensive summary of critical strategies to ensuring your imagery is fetched and rendered fast. Implement these approaches to improve your Core Web Vitals metrics.

### [How to Load Fonts in a Way That Fights FOUT and Makes Lighthouse Happy ](https://css-tricks.com/how-to-load-fonts-in-a-way-that-fights-fout-and-makes-lighthouse-happy/)

[Adrian Bece](https://twitter.com/AdrianBeceDev)

Text is a vital part of any site or application. Understand how to load fonts efficiently and prevent the flash of unstyled text (FOUT) and layout shifts.

### [Content-visibility and Accessible Semantics ](https://dev.to/marcysutton/content-visibility-and-accessible-semantics-2994)

[Marcy Sutton](https://twitter.com/marcysutton)

Content visibility has been quickly hailed the most impactful CSS property for improving performance. Learn about its drawbacks for accessibility.

# Tools

### [Publish, ship, and install modern JavaScript for faster applications](https://web.dev/publish-modern-javascript/)

[Jason Miller](https://twitter.com/_developit) & [Houssein Djirdeh](https://twitter.com/hdjirdeh)

Use [EStimator.dev](https://estimator.dev/) to calculate the size and performance improvement a site could achieve by delivering modern JavaScript syntax.

### [Introducing Zero-Bundle-Size React Server Components](https://reactjs.org/blog/2020/12/21/data-fetching-with-react-server-components.html)

[Dan Abramov](https://twitter.com/dan_abramov), [Lauren Tan](https://twitter.com/sugarpirate_), [Joseph Savona](https://twitter.com/en_JS), and [Sebastian Markbåge](https://twitter.com/sebmarkbage)

React Server Components will have zero effect on bundle size, which might significantly move the needle on JavaScript performance. The project is still in research and development, but the authors are calling for community feedback.

This email is brought to you by the team at [Calibre](https://calibreapp.com). Our performance monitoring platform helps you deliver stellar user experiences to everyone.

Performance Newsletter is sent from the traditional lands of the Wurundjeri people of the Kulin nation. We acknowledge that sovereignty was never ceded and pay respects to the Elders past, present and emerging.

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