To add WWW or not to add WWW?

1. What are the advantages and disadvantages of not adding www?

The main advantage of a domain name without www is that it is shorter and easier to remember. There are more disadvantages, and there are several main technical reasons:

Naked domain names can only be bound to DNS 's A record, not CNAME record. That is, you cannot set a naked domain as an alias for another domain name. Many times, this is not very convenient for management, especially when using a third-party hosting service. If the third-party migration server causes the IP address to change, you must change the DNS A record yourself .

For example, if your personal blog uses the Tumblr service, you use a naked domain, you need to manually point the domain name's A address to the IP address specified by Tumblr . If Tumblr moves the computer room, all users who set up their personal domain names in this way must change their DNS to continue using it, otherwise the service will be interrupted. Using a subdomain's CNAME record is relatively simple, just point the CNAME field of the www subdomain to the domain name domains.tumblr.com , and then if Tumblr changes the IP address, you only need to reset the A domain name domains.tumblr.com record without changing the DNS record for each user.

This technical limitation has caused many large third-party service providers to not support the use of naked domains. Typical services like Google cannot use naked domains now. Google 's service user base is large, so it must be distributed at the DNS level. There are too many IP addresses used , and they vary greatly. Letting users bind A records is not conducive to load balancing, and maintenance is also a nearly impossible task. Similarly, most CDNs do not support naked domains.

Regular matches of URLs (if they are prefixed with www and end with .com/.net/.org) generally have a greater chance of success. You will encounter this problem in many text editors. If the URL does not start with www and does not end with the first three domains, the chances of a successful match are much lower. This point sometimes drives people crazy during use. Whether it is important depends on your purpose and occasion.

Another non-technical consideration: the benefit of using the www subdomain reflects the offline environment, such as outdoor advertising, newspapers and magazines, voice broadcasts, voice calls, etc., which can clearly remind the audience of the www prefix (both visually and audibly) that this information is a website. Some people would say that adding the http : // prefix can also solve this problem, but now that browsers led by Chrome/Safari have begun to hide the http : // protocol prefix in the address bar, the understanding of these characters by ordinary users will become more and more vague, so even if it is offline, the visual / sound prompt www can still be retained .

Generally, naked domains are not recommended for websites with large traffic or multiple subdomains. For websites with less traffic or fewer subdomains, it depends on your personal preference. I really like naked domains. The "Single Page Web App " that has become popular in recent years mainly uses naked domains. Twitter is an example.

2. Will deleting www affect the website's SEO (mainly ranking and inclusion)? (The premise is that there was www in the past)

When naked domains first became popular there were indeed rumors, but now there seems to be no problem. If anything, they are a bug in the search engine. Tell them and they should be happy to fix them. Google 's webmaster tools have tools to help you with URL migration so you can effectively fix this issue and then work with the next part without having to worry about any negative impact on SEO .

3. What is the best way to redirect? (e.g. 301)

Regardless of whether you decide to use or not use a naked domain, it is best not to keep both the www prefix and the naked domain in the URL . This is inconvenient for user browsers to distinguish the access history, but it will also cause you a lot of trouble when doing access statistics. The best way is to use 301 to redirect and keep everything after the domain name in the URL when redirecting . For example, if you decide to use the naked domain http://abc.com , then be sure to change http://www.abc.com/foo/bar?spam=egg.

301 Jump to                                 

http://abc.com/foo/bar?spam=egg

Or conversely, if you decide not to use a naked domain, then be sure to

http://abc.com/foo/bar?spam=egg

SEO Advantages of Using www and Not Using www

With or without www , it has absolutely no impact on SEO . Even Google says it is all about your personal preference. Be sure to keep the same choice as when you built your website, in other words, don't just add or remove www from your website . It is just a personal preference for search engines to have or not have www .

Technical differences between using www and not using www

When you add www in front of a domain name , www acts as a hostname. It can help increase the flexibility of DNS . It can restrict cookies when using multiple subdomains . A domain name without www is also called a naked domain name and has no technical advantages.