Home Blog Software Development What is the Google Lighthouse tool, and can it improve your web application's speed?

What is the Google Lighthouse tool, and can it improve your web application's speed?

If you’re working on a new digital product, you want to ensure its functionality and quick, smooth operation. Google Lighthouse is one tool that comes in especially handy for both Progressive web apps (PWAs) and websites. Read on to see what Google Lighthouse is and how to use it to measure and improve your website’s performance.

What is the Google Lighthouse tool, and can it improve your web application's speed?

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If we had to squeeze the whole broad topic of website or PWA functionality into just one sentence, we’d say it has to offer sufficient performance, accessibility, and SEO-friendliness. Websites that tick these three major boxes offer satisfying UX and are ready to rank high on Google, thus enabling your online business to grow effectively.

Google supports website owners in creating well-performing webpages. They regularly publish new guidelines (e.g. concerning mobile-friendly web design) and offer free tools to assess the quality of your website. One such tool is known as Google Lighthouse. Believe us; every website owner should be acquainted with it.

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What is the Google Lighthouse tool?

It’s an open-source tool provided by Google as a part of their DevTools. You can use Google Lighthouse to audit your website or progressive web application (PWA) and verify its:

  • Performance (there are six factors that Google Lighthouse takes into consideration, many of them are related to Core Web Vitals).
  • Accessibility (Lighthouse uses over 40 different audits to verify accessibility, although even Google recommends running manual tests as well).
  • SEO-friendliness (there are three crucial elements to check: Do Google bots understand your website’s content? Can they crawl and index your site? Is your website mobile-friendly?)
  • Technical condition (e.g. if there are any browser errors).
  • Compliance with other Google and UX best practices (e.g. concerning security and not using deprecated technologies).

There is also a separate PWA audit intended for just this type of digital product. Within this audit, Google’s tool verifies whether your progressive web app is fast, reliable, installable, and if all the elements in your app are PWA-optimized.

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The Google Lighthouse tool: How to use it

If you own a website or a PWA app and you want to run a Google Lighthouse audit, you don’t have to download anything or even have advanced IT knowledge.

All you need is a Chromium-based web browser (Google Chrome, Opera, Microsoft Edge, Brave). Go to a website you want to audit (you need to give Lighthouse a specific URL address), open the control panel in your browser (in Chrome, you can find a button with three vertical dots in the upper-right corner), choose the “More tools” section and then “Developer tools”. You will see several tabs in the upper part of this section. One of them is called “Lighthouse”. That’s where you need to be.

Once you click it, you will see a list of elements that can be audited. Select the ones you want (or just go with everything) and generate the report. In a few moments, you will get a comprehensive view of your website’s condition. The Google Lighthouse tool provides information on what works correctly and what should be improved. You will also find out about any significant issues that need to be fixed.

There are other ways to open Google Lighthouse (e.g. through a Chrome extension or from the command line), but the way we describe above is the quickest and most straightforward one. This method comes with a certain risk: some plugins can affect the result of the test, if remain switched on.

How to use Google Lighthouse to improve site speed

If your website’s speed is your major concern, go with the Navigation mode, where performance is the first thing that’s verified. Once the report is ready, you will get a list of opportunities that will help you shorten the page load time. For example, such recommendations might include:

  • Reduce initial server response time
  • Properly size images
  • Serve images in next-gen formats (primarily the strongly encouraged by Google WebP format)
  • Eliminate render-blocking resources
  • Reduce unused JavaScript code

Each recommendation comes with an estimated time reduction. Provide this list to a consultant or the company managing your website and ask them to implement Lighthouse’s suggestions.

When should you use the Google Lighthouse tool?

This tool should be in continuous use at your company. It’s best to use it:

  1. At the prototyping stage (before your digital product is released).
  2. Every time you implement some changes on your website or in your PWA.
  3. When you implement or change an SEO strategy.
  4. When Google releases new guidelines for website owners.
  5. If you notice disturbing signs concerning your website’s behavior (e.g. a decline in visits).

Are there any alternatives to Google Lighthouse?

There are, although their functionality is limited. Typically, Google Lighthouse alternatives concentrate on your website’s performance. But there is one more tool that’s worth your attention: WebPageTest.org. It’s a free tool that offers five different tests:

  • Core Web Vitals
  • Site performance
  • Lighthouse
  • Visual comparison
  • Traceroute

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What are the benefits of testing applications and websites with the Google Lighthouse tool?

Using the Google Lighthouse tool is the first step on the way to ensuring that your website or PWA works effectively and in full compliance with the latest Google requirements. Thanks to the thorough audits offered by this tool, you get access to all the relevant information about your webpage/app and have a ready-made list of improvements and changes that need to be applied.

This tool comes in handy, particularly when you work with an IT or product development company or an in-house development team. They can use Google Lighthouse insights to eliminate all the weak points in your product and improve their testing processes by knowing what to focus on.

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The Google Lighthouse best practices and summary

You have to bear in mind that Google Lighthouse is just a tool; it can give you some ideas and suggestions on what should be done or fixed on your website, but it shouldn’t replace common sense and manual verifications. Not every suggestion will be worth implementing or even beneficial for your website. Lighthouse is mostly based on general guidelines and data from other apps and websites, so it’s not an oracle.

There are some more factors to keep in mind when using this tool:

  • Many elements can impact the audit’s result, including the network you’re using and extensions installed in your internet browser.
  • It’s usually best to run Google Lighthouse audits in Incognito mode.
  • If you have a product development team working on your app or website, and many changes are being implemented, adding Lighthouse to your project’s CI (continuous integration) system is beneficial.

Now you know everything you need to discover more information about your website. Run a Google Lighthouse audit today and start improving your website’s operation and position with the largest search engine.