Note: Check the speed of your website using a free performance service such as GTMetrix. This service will inform you of your page loading time and the overall file size of your page. They also offer tips which you can apply using third party plugins such as WP Rocket plugin.
A good plugin to optimize images that have already been uploaded is WP Smush.it. It utilizes the Smush.it API to optimize JPEG images, strip meta data from JPEGs and convert GIF images to PNG. You should however be aware that the plugin uses up a lot of resources when it is converting images, therefore your website may be slow whilst it is running.
Smush.It is a web service from Yahoo where you can upload your images and download the compressed version of them after some process.
There is a very robust app for Mac users called ImageOptim. Just drag the image to the app and it will compress and replace it with the original one. Simple and free.
PNG Gauntlet is a windows software which works great when it comes to PNG compression. Working with it is easy and it is free.
More information about image optimization you can find in this blog post.
One of the best methods to speed up the website is reducing the server requests for the website. This can be achieved by caching the website and serving the cached version of pages instead of requesting the whole backend process from the server. To learn more about different caching plugins, how to install and use them, check out this article.
Content Delivery Network
Content delivery network is a method of distributing different assets like images and media files between different locations with the goal of reducing the main server load. This method boosts the speed of the website to a great extent. There are many CDN providers on the market. Here is the list of recommended ones by us:
This service has a free plan which is enough for most personal websites. Needless to say by purchasing other plans from this service the website speed sometimes increases two times.
This is a professional service and has different plans to choose from. They provide a very robust and satisfactory service.
This is one of the most famous CDN services on the market provided by Amazon. If you are a professional webmaster and have a website with a large amount of information, this service is for you.
CSS and JS Minification
Gzip compression allows a website page to be transferred to a browser at up to 70% of its original size. The browser will then decompress the page and display it to the user. Gzip can be enabled via the WordPress options page. You can find this page at www.yourwebsite.com/wp-admin/options.php. To enable Gzip, simply change the value of the Gzip field from 0 to 1.
Also you can contact your hosting provider support to enable the Gzip Compression on your server.
Monitor your Plugins
Plugins are one of the biggest causes of WordPress websites being slow. The more plugins you install without research, the more likely you will face performance issues. Certain plugins are known for causing websites to be slow. There are many reasons for this including bad coding, calls to external servers and persistent calls and updating of your WordPress database. Pay close attention to how much CPU plugins use too. Many plugins can bottleneck your CPU due to persistent processes. Keep the number of activated plugins at the minimum.
Note: 80% of good site performance is related to installing a good caching plugin, setting up a good server, using CDN, optimizing images, building not lengthly pages.
Note that scores also depend on the length of the page and number of images, and amount of html content.
- Forget about the deferring the JS, it will ruin your website since there is actually no way you can guarantee which JS file is needed for each page.
- Try to add leverage browser caching rules in your .htaccess file.
- Add expiration headers to your .htaccess file.
- Make sure to keep the number of activated plugins at the minimum.