How to Troubleshoot A Slow Loading Website

More and more these days, a high search engine page rank is imperative. The ideal website load time for mobile sites now should be under 3 seconds, and honestly, the faster, the better! The average time it takes to load an entire mobile landing page is approximately 22 seconds, but 53% of visits are abandoned if a mobile site takes longer than 3 seconds to load.

This means that a slow loading website can lead to a substantial NEGATIVE impact on ranking factors in Google. These rankings are a nuanced process by which Google evaluates more than 200 signals, and now, the mobile page speed load time is one of the significant factors. 

This article will review some of those factors that can be controlled and improved upon to address a slow loading website. 

Prerequisites

When troubleshooting a slow loading website, the first thing we should do is run a baseline, so we have a future reference to which we can refer. We do this to see how much of a difference our changes have made. This measurement allows us to compare and contrast increases or decreases in load time.

To accomplish this, we can use several online tools that provide an excellent method to obtain that data. Here are three sites that provide superior feedback on performance affecting issues. 

• Pagespeed Insights
• Websitetest
• GTMetrics

Other Factors

As a side note, it should be mentioned that distance, network speed, routing issues, computer speed, and multiple other factors can come into play here as well. This is why selecting a standard timing budget we want to aim for is so important. Eliminating as many variables in our testing framework will provide an increase in accuracy when testing.

Metrics

Metrics are the measurements we employ to determine the optimal load and performance times of a site. The type of metrics will vary with the tool used, but most of the primary measurements used are based on two main areas; Performance Metrics and Browser Timings. Typically, performance scores and timings are weighted as some factors are more critical to usability than others. 

Performance Metrics

Each of these metrics is weighted at anywhere from 5% to 25%. 

• First Contentful Paint — FCP determines how long it takes a browser to render the first piece of DOM content that loads after a client hits your page. The lower the FCP score, the better the results.
• Speed Index: The speed Index determines how quickly visual content is displayed when a page loads.
• Largest Contentful Paint: LCP measures the time it takes for the largest image or text block.
• Time to Interactive: The TTI measurement notes how long it takes a webpage to become completely interactive.
• Total Blocking Time: The TBT measurement is defined as the entire time a page blocks user input. This includes mouse clicks, screen taps, keyboard presses, or other input methods. 
• Cumulative Layout Shift: CLS measures the totals of every single layout shift score for any unexpected shift in a website’s layout, which happens during the full life of the webpage.

We can see these results in several online tests which provide the results of our scans. Additionally, some online calculators provide a more in-depth means to identify how each score affects our website. It also allows us to choose either the mobile or desktop version of a website. From experience, your mobile site is more important to site rankings to Google.

Browser Timings

• Redirect Duration — The total time used redirecting URLs before the full page load
• Connection Duration — The time spent connecting to the server
• Backend Duration — The time take to generate a server response
• Time to First Byte (TTFB) — The total time consumed receiving the first byte
• First Paint — The point at which the browser begins page rendering
• DOM  (Document Object Model) Interactive Time — This measures the time it takes for the browser to finish loading and parsing the HTML
• DOM Content Loaded Time —  The point at which the DOM tree is loaded
• Onload Time — This measurement indicates when the page has finished downloading.
• Fully Loaded Time — The point when the following conditions have occurred
  • First Contentful Paint has happened
  • Onload has happened
  • The Network and CPU are idle

These metrics are used to gauge a website’s overall usability, speed, and performance.

Areas of Issue or Concern

The following recommendations are typically used to ensure a website is optimized fully. We have divided the concerns up into multiple categories to try to be as granular as possible. These areas include:

• Website code
• CMS related optimizations
• Website concerns
• OS/Server problems
• Hosting issues

Website Code 

• A website’s code size can be considerable — Limit objects to 20-30 per page
• JavaScript — Large JS elements can delay page load times
• Minimize/Optimize Code, CSS, and Javascript — Removing unneeded characters from code reduces its size, which improves load times. 
• Limit CSS expressions — These are evaluated when a page is rendered, resized, scrolled, and the user moves their mouse over the page. 
• Use gZIP Compression — Using gzip reduces the overall response times by reducing the HTTP response size.
• Load stylesheets first
• Load scripts last
• Limit DOM objects — The more complex the page, the longer the load time.
• JavaScript & CSS External — There are two proper ways of accessing them
  • Inline (i.e., within the HTML code)
  • External (i.e., in external files cached/stored by the browser, e.g., Firefox)
• Limit ETag usage — If not using the ETag validation model, it’s better to remove them altogether. 

CMS Related Optimizations

• Keep CMS updated 
• Keep all plugins, add-ons, and themes updated
• Remove/Replace resource-intensive plugins, add-ons, and themes
• Avoid Heavy Plugin usage 
• Limit large graphics and media files
• Compress/resize/optimize large images to less than 100k
• Flash is dead — reduce or eliminate this multimedia software
• Keep all page components small — 50k-100k max
• Use a modal window to push videos or large pictures
• Limit the number of external page elements  
• Minify all files
• Avoid empty src or href tags — the browser makes more requests when this occurs
• Consider using the AMP HTML framework
• Enable CMS specific optimizations (WordPress, Joomla, Drupal, and WooCommerce)

Website Concerns

• Conflicting scripts can cause slowdowns
• Avoid or limit the use of external advertisers
• Add Expires or Cache-Control Header
  • Implement “Never expire” for static components
  • Use appropriate Cache-Control header for dynamic components
• Place stylesheets at top of page
• Avoid redirects if possible — a redirect slows the user experience
• Minimize cookie file size and eliminate unnecessary cookies
• Enable lazy loading of images and videos
• Combine files if possible
• Disable hotlinking
• Combine Google fonts

OS/Server Problems

Internal Issues

• Keep server software updated/upgrade
  • Apache/nginx
  • Database software
  • CMS
  • PHP
  • Python
  • Perl
• Add and enable caching
• Check server response times
• Use a CDN
• Limit API calls to external services
• Excessive overhead in the database can slow a site
• Clean and optimize the database often
• Hosting provider platform should be stable and with minimal downtime
• Reduce DNS Lookups — This takes 20-120 milliseconds for DNS to lookups to complete. Implement DNS prefetching.
• Excessive load can cause a slow server, increasing load time
• Server Location — the farther the server is from the user, the longer it can take to load a site.
• Monitor server health regularly.

External Issues

• Optimize external resources being pulled from an outside website
• High HTTP requests — Reduce the number of rendered page components
• Network issues — Latency or network congestion can impact load times
• ISP issues — Network performance can vary greatly by provider.
• Browser issues — Incompatibility, limited functionality, or other factors can play a part in a website loading slowly.

Hosting Issues

• Choose The Right Host — Check uptime, support models, reliability, and other factors.
• Use a reputable developer who understands how all these issues can affect performance.

Diagnostic Tools

Multiple online tools have an established reputation for providing reliable information when reviewing all these aspects. Some of these tools include:

• Google Analytics
• GTmetrix
• Google Page Speed Insights
• YSlow
• Webpagetest.org 

Users can employ these tools in tandem to provide a complete image of what steps should be taken to troubleshoot a slow loading website. 

Conclusion

Lastly, do not let the good become the enemy of the perfect. A solid score might be improved upon, but you should ask yourself these questions before running down this rabbit hole.

• Will users notice an improvement? Optimizations may minimally improve speed but, is it worth investing your time and money on a developer for a small decrease in load time?
• Is investing in the changes worth the trouble? Optimization can require many changes and can include drawbacks that could require many hours of work.
• Is the cost defensible? Is a developer needed to do the work for you? Does his cost justify the necessary improvements?

Website speed is important because it usually improves a sites search engine rankings. Using the above information can reduce overall load times and increase customer retention. Additionally, fast sites typically receive more traffic and have better conversion rates. It is well worth your time to investigate these issues and correct or eliminate any problems that slow down the speed of your website.

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