What Does "URL Too Long" Mean?
A URL is considered too long if it is longer than 100 characters.
Why It's Important
An overly long URL can cause both usability and search engine issues:
Any potential benefit you may have by including keywords in the URL will be diluted since it's such a small percentage of the total URL text.
Longer URLs are truncated by search engines, in web browsers, and many other areas
Visitors like to see clean, human-readable URLs since it makes them easy to read, remember, and type. A long, unwieldy URL can be a usability issue. It could potentially also lead to lower click-through rates on the SERP.
Very long URLs are often a symptom of other issues, such as having too many parameters in the URL, which can lead to other problems
How To Fix
There are several things that you can do to avoid URLs that are too long:
If using dynamic URLs with URL parameters, use server-side URL rewrites to convert them into static, human-readable URLs
Try to minimize the number of parameters in the URL whenever possible
If using URL rewrites, consider truncating them at a maximum length. This is especially important if you're rewriting them programmatically using page data such as page title - long titles will result in very long URLs.
A Word of Caution
When making changes to many URLs of existing pages on your site, it's important to remember that this process can be tricky and potentially risky if not done correctly. If the changes are not made correctly, it could result in the de-indexation or lower ranking of pages on your site. Therefore, the relatively small benefits that come from undertaking these changes may or may not be worth it for your site.
The process for fixing URLs on your site depends on multiple factors and is too detailed to list here. Instead, remember a few important principles when updating many or all of the URLs on your site: