Issue 18—The cost of third-party scripts, performance auditing, variable fonts and more!

        25 May 2018

#### PerformanceNewsletter

#### Issue 18

#### Editor’s Note

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 As mobile speed metrics will begin to affect SEO negatively, we’ve seen an influx of talks and new tooling evangelising the importance of performance. We hope you’ll enjoy what we’ve selected for this issue. ✌🏻

— Karolina & Ben

#### talk

## Determining the cost of third-party scripts

External scripts, whether it’s ads, analytics, social media or integrations can have a profound impact on performance and privacy. Did you know that on average, some of the top-ranked websites on Alexa include resources from over 22 different domains? Ouch!

Thanks to [Trent Walton](https://twitter.com/trentwalton), we can understand third-party scripts better and more importantly, implement approaches to counter performance regressions.

[name that script →](https://speakerdeck.com/trentwalton/name-that-script)

#### talk

## Step-by-step performance auditing

Performance can be incredibly nuanced, hard to debug and grasp. At Google I/O [Ewa Gasperowicz](https://twitter.com/devnook) and [Addy Osmani](https://twitter.com/addyosmani) performed a live audit of Google Doodles using recommendations from [Lighthouse](https://developers.google.com/web/tools/lighthouse/) and other performance tooling. Watch the talk to learn how to run your audits!

[web performance made easy →](https://www.youtube.com/watch?v=Mv-l3-tJgGk&index=45&list=PLOU2XLYxmsIInFRc3M44HUTQc3b_YJ4-Y)

#### browser

## Fast typography with variable fonts

[Variable fonts](https://css-tricks.com/one-file-many-options-using-variable-fonts-web/) is a specification that in the future will allow significant performance savings in the typography realm. In a nutshell, we will be able to substitute multiple font files with one, that can be morphed to our needs (for example via *font weight*).

In this excellent demo, [Jason Pamental](https://twitter.com/jpamental) demonstrates the variability of FF Meta typeface.

[Getting Started With Variable Fonts →](https://www.monotype.com/fonts/variable-fonts/)

#### report

## When 4G isn’t fast enough

Open Signal provides insightful reports into the state of connectivity and mobile experience. This time, they take a look at India, highlighting the exponential growth in availability, but disappointing 4G speeds.

Another great reminder that not all connection profiles are equal.

[State of Mobile Networks: India (April 2018) →](https://opensignal.com/reports/2018/04/india/state-of-the-mobile-network)

#### article

## Improving media performance with data

In his deep-dive, [Doug Sillars](https://twitter.com/dougsillars/) takes a close look at the state of performant imagery based on BigQuery, WebPageTest and Lighthouse data. He draws fascinating conclusions about the impact of images on metrics and which strategies are worth investing in.

[State of the Web: Top Image Optimization Strategies →](https://dougsillars.com/2018/05/21/state-of-the-web-top-image-optimization-strategies/)

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