What Is a Permalink?
A permalink is the permanent web address (URL) of every post and page on your WordPress site. For example, yoursite.com/wordpress-installation is a permalink. The structure of these addresses directly affects both the visitor experience and your SEO. Meaningful, readable URLs that contain keywords are better for both users and Google; complex, number-based addresses look weak and are a disadvantage for SEO.
How to Choose an SEO-Friendly Permalink Structure
In your WordPress dashboard, go to Settings > Permalinks. You will see several options:
- Plain: yoursite.com/?p=123 — unreadable and bad for SEO. Never use it.
- Day and name: Contains the date and makes URLs unnecessarily long.
- Post name: yoursite.com/post-title — the most recommended structure. It is short, meaningful and keyword-friendly.
If you are setting up a new site, be sure to choose the "Post name" option. Your URLs will be clean, memorable and search-engine friendly.
Things to Watch Out for When Changing Permalinks
Changing the permalink structure of a site that is already live and ranking on Google is risky. Because the old addresses will no longer work, both visitors and Google will hit 404 errors and your rankings can suffer. If you must change the structure, you have to set up 301 redirects from the old URLs to the new ones. You can use a plugin like "Redirection" for this. Whenever possible, it is best to choose the right permalink structure at the very beginning of the setup and never change it again.
What Is a 404 Error and Why Does It Happen?
A 404 error means that the page the visitor is trying to reach cannot be found. The most common scenario in WordPress is this: the home page opens, but when you click on inner pages (posts, categories) they all return a "Page not found" error. This usually stems from a corrupted or missing .htaccess file, a site migration, or permalink settings that were not saved properly.
Fix 1: Re-Save Your Permalinks (The Most Common Fix)
If you are getting 404 errors on inner pages, the first thing to do is this: go to Settings > Permalinks and, without changing anything, click the "Save Changes" button. This simple action makes WordPress rewrite the .htaccess rules and, in the vast majority of cases, instantly resolves the 404 problem.
Fix 2: Check the .htaccess File
If the step above did not help, your .htaccess file may not be writable or may be corrupted. Open the .htaccess file in your site's root directory via FTP and make sure it contains WordPress's standard rules:
# BEGIN WordPress
RewriteEngine On
RewriteBase /
RewriteRule ^index\.php$ - [L]
RewriteCond %{REQUEST_FILENAME} !-f
RewriteCond %{REQUEST_FILENAME} !-d
RewriteRule . /index.php [L]
# END WordPressIf the file does not exist, create a new .htaccess with this content and upload it to the root directory. If the file exists but is corrupted, replace its content with these standard blocks.
Fix 3: Make Sure mod_rewrite Is Enabled on the Server
For SEO-friendly URLs to work, the mod_rewrite module must be enabled on the Apache server. On most hosting this is on by default; however, if you manage your own server or are getting 404 errors on a local installation, check whether this module is enabled (or ask your hosting provider).
Fix 4: 404 Errors After a Site Migration
If you have recently migrated your site and the inner pages return 404 errors, the cause is most likely an .htaccess file that was not migrated or that contains the old paths. Applying Fix 1 (re-saving the permalinks) is usually enough in this case too.
404 on Specific Pages and Posts (Individual Cases)
Sometimes the site as a whole works fine and only a specific page returns a 404. There are a few typical reasons for this. The page may have been deleted or set to draft; check its status from the dashboard. The page's permalink (slug) may have been changed; links pointing to the old address no longer work, in which case set up a 301 redirect from the old address to the new one. Another reason is two pieces of content trying to share the same slug; although WordPress resolves this conflict automatically, it can sometimes cause issues. To detect individual 404s, regularly check the "Not found (404)" section of the "Page Indexing" report in Search Console.
Managing 404 Errors from an SEO Perspective
Not every 404 error is necessarily bad; for content that has genuinely been removed and has no replacement, a 404 (or a 410, which means permanent removal) is the correct response. But if a valuable page that has earned links or is ranking returns a 404, that is a loss for both visitors and SEO. In that case the right solution is to move that page to the most relevant new address with a 301 redirect. This way the old link does not lose its strength and its visitors, and you bring the user to useful content instead of an empty error page. Decide which 404 should be redirected and which should be left as is based on the page's value.
Frequently Asked Questions (FAQ)
I'm getting 404 errors on inner pages, what should I do first?
Go to Settings > Permalinks and, without changing anything, click the "Save Changes" button. This makes WordPress rewrite the .htaccess rules and, in most cases, instantly resolves the 404 problem.
Which permalink structure should I choose?
Choose the "Post name" structure: yoursite.com/post-title. It is short, meaningful and keyword-friendly. Never use the "Plain" (?p=123) structure.
Can I change the permalink structure later?
You can, but it is risky on a live, ranking site; the old addresses will return 404. If you must, set up 301 redirects from the old URLs to the new ones. The best approach is to choose the structure correctly at the start of the setup.
Conclusion
Most 404 errors in WordPress are solved with simple steps such as re-saving the permalink settings or fixing the .htaccess file with the standard rules. Choosing the "Post name" structure from the very start and never changing it again means both clean URLs and fewer problems. Track individual 404s in Search Console and redirect valuable pages with 301.