Answered by
Oliver Hall
Hashbang (#!) URLs refer to a method of AJAX navigation that was historically used in web applications. The #! symbols in the URL signify a hashbang, which tells the browser and search engines that what follows is a single-page application's state, not a traditional URL path. Due to the complexity and uniqueness of these URLs, indexing them can be challenging for search engines.
A typical hashbang URL might look something like this:
http://www.example.com/#!about
In this example, http://www.example.com/ is the base part of the URL, and #!about is the hashbang part, indicating that the 'about' state of the app should be loaded dynamically by JavaScript.
Initially, Google provided a scheme for making AJAX-based websites crawlable. This involved using a special format with hashbang (#!) and handling requests that included _escaped_fragment_. If Google detected a hashbang URL, it would attempt to crawl an alternate version of the page by replacing #! with ?_escaped_fragment_=. For example, Google would translate:
http://www.example.com/#!about
to
http://www.example.com/?_escaped_fragment_=about
The server needed to return a static HTML snapshot of the page corresponding to this fragment for Googlebot to render and index the content effectively.
Due to advancements in Google's rendering capabilities and broader changes in web development standards, Google announced in 2015 that it no longer requires the AJAX crawling scheme described above. Modern Googlebot can now render JavaScript-heavy pages more like an actual browser, meaning that many dynamic elements of websites, possibly including those relying on hashbangs, are automatically crawlable and indexable without special accommodations.
That said, the use of hashbang URLs is generally discouraged as newer technologies like HTML5 pushState are preferred for managing dynamic content in single-page applications (SPAs). These methods are cleaner and more seamlessly supported by search engines.
If you are developing or maintaining a site with hashbang URLs, consider migrating to a more modern JavaScript framework or architecture that uses HTML5 history APIs. This approach improves both the user experience and compatibility with search engine crawlers.