New in Calibre: JavaScript parse
and compile runtime metrics

Ben Schwarz
Nov 22, 2017 · 2 min read

After a busy November, we’re pleased to let you know that Calibre will now help you understand another vector of web performance.

🏃‍♀ JavaScript runtime metrics

Runtime execution of JavaScript is what we’ve identified as a major hidden cost for performance on the web. Up until recently, the web performance community hasn’t had a firm grasp on the reporting of these crucial metrics outside of browser dev tools. No more!

If you’ve had a hunch that a particular ad network, tracking script or chat system is slowing down your site, wonder no more. 🎯

📱New test profiles

Test profiles are how Calibre splits up device and bandwidth tests — here are a few small updates to help you test devices more thoughtfully.

First up, when creating a site, the new default profile arrangement will be:

  • Chrome Desktop with an unthrottled network connection
  • Motorola Moto G4, with a 3G connection

Previously we were using an iPhone 6 instead of a Moto G4, but after some reflection, we wanted to provide a default profile that better described a global average smartphone.

There are two new test profile devices to choose from: iPhone 7 and iPhone 8. These more modern phones have extremely fast CPUs and offer near-desktop JavaScript performance.

Help us spread the word about Calibre

As always, we’d love to see more companies using Calibre to help make the web a faster place. If you can help spread the word, that’d mean the world to us. 🤗

Calibre Blog

Everything you have to know about site speed and performance.

Calibre Blog

Calibre is an all-in-one speed monitoring platform with transparent reports and actionable advice to make your sites fast. We write about the newest developments in site speed and share how we build our bootstrapped business.

Ben Schwarz

Written by

Founder of Calibreapp.com

Calibre Blog

Calibre is an all-in-one speed monitoring platform with transparent reports and actionable advice to make your sites fast. We write about the newest developments in site speed and share how we build our bootstrapped business.

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