Why Is Pinterest Website So Slow? Here Are The Reasons

Pinterest is an American image-sharing website that receives over 1 billion visits each month from both desktop and mobile (according to SimilarWeb). The company has reported annual revenues of over $2.8 billion as of 2022

A speed report from Lighthouse paints a rather grim picture and scores the Pinterest website 5.5 seconds on the speed index (SI), and 67 on Performance.

There are many reasons why the Pinterest website is so slow. This includes:

• Bloated JavaScript files
• Slow server
• Large DOM size
• Ineffective Caching Policy

Let’s look at each of these reasons and identify potential ways that Pinterest can make its website load faster.

But before we do that, a quick word about our website CWVIQ.com - we are a free email alert service that sends out notification any time your website is loading very slowly (often due to heavy traffic, or poor scripts). If you have a website, consider setting up an alert so that you can fix issues before they become major. 

Bloated JavaScript files

Pinterest uses a lot of JavaScript to run the website. However, loading them all from one source could slow up the performance of the website. Pinterest can avoid this by splitting the code into smaller files. This way, you only load files that are necessary.

The Pinterest website can be as much as 2.77 seconds faster by adopting this technique.

Slow server

According to the Lighthouse report, a slow server may be contributing to nearly 0.63 seconds of additional loading time. In addition to upgrading the server hardware and database systems, Pinterest should also look into the server’s application logic to prepare pages faster.

Large DOM size

The Pinterest website takes close to 6.8 seconds to evaluate all the scripts, parse them, compile, and render them. This can be minimized by minimizing the main-thread work.

They may also look at reducing the number of nodes in the DOM. In simpler terms, you need to make sure that the main HTML code is smaller and has fewer nodes. I have explained this in greater detail in this article about DOMContentLoaded.

Ineffective Caching Policy

A website like Pinterest is made of several components, including a lot of images, and other media files. Caching, or storing these components in your local computer, enables your browser to load the website much faster when you come back a second or third time.

With Pinterest however, the cache for most media files clear is deleted every 14 minutes. This means that the website is loaded completely from scratch any time you visit after 14 days. Enabling a longer cache period could make loading pages faster and more user-friendly.