{"id":13634,"date":"2022-05-20T04:43:14","date_gmt":"2022-05-20T04:43:14","guid":{"rendered":"https:\/\/www.searchenginejournal.com\/6-javascript-optimization-tips-from-google\/451021\/"},"modified":"2022-05-20T04:43:14","modified_gmt":"2022-05-20T04:43:14","slug":"6-javascript-optimization-tips-from-google-via-sejournal-mattgsouthern","status":"publish","type":"post","link":"https:\/\/marketingnewsbox.com\/?p=13634","title":{"rendered":"6 JavaScript Optimization Tips From Google via @sejournal, @MattGSouthern"},"content":{"rendered":"
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In a new video from Google, Developer Advocate Alan Kent shares six ways to optimize JavaScript to improve the performance of your website.<\/p>\n

Kent identifies common performance problems caused by JavaScript and goes over steps you can take to fix them.<\/p>\n

1. Avoid JavaScript File Proliferation<\/h2>\n

Avoid proliferation in the number of JavaScript files on your site.<\/p>\n

The number of JavaScript files could become excessive if you\u2019re not careful, especially if each UI component is in a separate file.<\/p>\n

Reducing the number of JavaScript files a browser has to download can improve website performance.<\/p>\n

How To Detect<\/h3>\n

The Opportunity<\/strong> section of the PageSpeed Insights<\/strong> report lists recommendations specific to your site.<\/p>\n

Look for the recommendation to keep request counts low and transfer sizes small<\/strong>.<\/p>\n

Click on the recommendation for a summary of the number and sizes of resource types requested including JavaScript files.<\/p>\n

How To Fix<\/h3>\n

You can fix this problem in a number of different ways. One option Google recommends is to combine smaller files together to have a single, larger file to download.<\/p>\n

Another fix is to support HTTP2 on your site, as it can improve performance without joining files.<\/p>\n

2. Avoid Excessive DNS Lookups<\/h2>\n

Avoid an excessive number of DNS lookups for the reference JavaScript files, as this can slow down a user\u2019s first visit to your site.<\/p>\n

How To Detect<\/h3>\n

PageSpeed Insights can show you a list of domain names used in URLs in sections such as reduce JavaScript execution time<\/strong>.<\/p>\n

The network tab in Chrome Developer Tools is another way to see all the domain names referenced.<\/p>\n

How To Fix<\/h3>\n

To reduce the number of DNS lookups, Google suggests you consider hosting a copy of externally referenced JavaScript files on your own site.<\/p>\n

3. Eliminate Inefficient JavaScript<\/h2>\n

Reduce or eliminate inefficient JavaScript, as it can slow down webpages and lead to poor user experiences.<\/p>\n

How To Detect<\/h3>\n

Look for the following opportunities in Google\u2019s PageSpeed Insights report:<\/p>\n