Improve page speed loading using CDN and async or defer attribute

1. Which is better async or defer?
2. What is the use of defer attribute?
3. How do you load third party code after your page has primarily finished loading?
4. How can I make scripts load faster?
5. Can we use both async and defer?
6. Which is faster defer or async?
7. What is purpose of class attribute?
8. What defer means?
9. How do you use defer?
10. How do you fix reduce the impact of third party code?
11. Do iframes slow down page load?

Which is better async or defer?

DEFER always causes script execution to happen at the same time as or later than ASYNC. Presumably, scripts are made DEFER or ASYNC because they are less important for the critical content on the page. Therefore, it's better to use DEFER so that their execution happens outside of the main rendering time.

What is the use of defer attribute?

The defer attribute is a boolean attribute. When present, it specifies that the script is executed when the page has finished parsing. Note: The defer attribute is only for external scripts (should only be used if the src attribute is present).

How do you load third party code after your page has primarily finished loading?

How do you load third-party script efficiently?

1. Load the script using the async or defer attribute to avoid blocking document parsing.
2. Consider self-hosting the script if the third-party server is slow.
3. Consider removing the script if it doesn't add clear value to your site.

How can I make scripts load faster?

Speed Up Your Javascript Load Time

1. Find The Flab. Like any optimization technique, it helps to measure and figure out what parts are taking the longest. ...
2. Compress Your Javascript. ...
3. Debugging Compressed Javascript. ...
4. Eliminating Tedium. ...
5. Optimize Javascript Placement. ...
6. Load Javascript On-Demand. ...
7. Delay Your Javascript. ...
8. Cache Your Files.

Can we use both async and defer?

if you specify both, async takes precedence on modern browsers, while older browsers that support defer but not async will fallback to defer . These attributes only make sense when using the script in the head portion of the page, and they are useless if you put the script in the body footer like we saw above.

Which is faster defer or async?

Whereas DEFER scripts don't execute until the HTML document is done being parsed (AKA, DOM Interactive or performance. timing. domInteractive). Comparing the ASYNC and DEFER waterfalls, we see that using DEFER makes DOM Interactive fire sooner and allows rendering to proceed more quickly.

What is purpose of class attribute?

The class attribute specifies one or more classnames for an element. The class attribute is mostly used to point to a class in a style sheet. However, it can also be used by a JavaScript (via the HTML DOM) to make changes to HTML elements with a specified class.

What defer means?

defer, postpone, suspend, stay mean to delay an action or proceeding. defer implies a deliberate putting off to a later time.

How do you use defer?

Defer sentence example

1. "You must defer to him in my absence as you do me," he reminded her. ...
2. consented to defer his Crusade until March 1222. ...
3. There was still no improvement in the countess' health, but it was impossible to defer the journey to Moscow any longer.

How do you fix reduce the impact of third party code?

Reducing The Impact Of Third-Party Code

1. Find Third-Party-Code In WordPress.
2. Lazy Load YouTube Videos.
3. Host Google Fonts Locally.
4. Host Google Analytics Locally.
5. Host Facebook Pixel Locally.
6. Host Gravatars Locally.
7. Delay Third-Party JavaScript.
8. Defer Parsing Of JavaScript.

Do iframes slow down page load?

Every iframe on a page will increase the memory used as well as other computing resources like your bandwidth. ... To avoid having your iframes slow down your pages, a good technique is to lazy load them (i.e., loading them only when they are required like when the user scrolls near them).