Is the provided SharePoint site URL available, or is it already taken?<\/strong><\/p>\n\n\n\nApproach 1: Checking the Site via SharePoint REST API<\/h2>\n\n\n\n
The most obvious approach is to simply check whether a site exists under the given URL.<\/p>\n\n\n\n
One way to do this is by sending a request to the SharePoint REST API and trying to read basic site information, such as the site title:<\/p>\n\n\n\n
https:\/\/<tenant>.sharepoint.com\/sites\/<siteUrl>\/_api\/web?$select=Title<\/code><\/pre>\n\n\n\nBased on the HTTP response, we might interpret the result as follows:<\/p>\n\n\n\n
\n- 200 OK
<\/strong>The site exists and is accessible so the address is not available.<\/li>\n\n\n\n- 403 Forbidden
<\/strong>We don\u2019t have permissions to access the site \u2014 which still means the site exists.<\/li>\n\n\n\n- 404 Not Found
<\/strong>The site does not exist, so the URL must be available.
Right?<\/li>\n<\/ul>\n\n\n\nAt first glance, this logic seems correct. If SharePoint says the site is not found, we should be able to create a new site with that URL.<\/p>\n\n\n\n
Unfortunately, this assumption is wrong.<\/p>\n\n\n\n
Approach 2: Handling Deleted (Soft-Deleted) Sites<\/h2>\n\n\n\n
The first approach works only as long as no one has deleted a site with the same URL.<\/p>\n\n\n\n
When a SharePoint site is deleted, it is not removed permanently right away. Instead, it goes into a soft-deleted state<\/strong> and remains there for 93 days<\/strong>, during which it can still be restored.<\/p>\n\n\n\nDuring this period:<\/p>\n\n\n\n
\n- The site cannot be accessed<\/strong><\/li>\n\n\n\n
- The REST API call returns 404 Not Found<\/strong><\/li>\n\n\n\n
- A new site cannot be created using the same URL<\/strong><\/li>\n<\/ul>\n\n\n\n
This creates a dangerous situation:<\/p>\n\n\n\n
The REST API indicates that the site does not exist, but SharePoint still blocks the URL. So while Approach 1 returns 404<\/strong>, the URL is not actually available<\/strong>. Clearly, we need a better solution \u2014 one that also accounts for deleted sites<\/p>\n\n\n\nTo properly validate whether a SharePoint site URL can be used, we can leverage the following internal SharePoint API endpoint:<\/p>\n\n\n\n
https:\/\/<tenant>.sharepoint.com\/_api\/GroupSiteManager\/GetValidSiteUrlFromAlias?alias='mySite'<\/code><\/pre>\n\n\n\nThis endpoint returns a validated site URL<\/strong> based on the provided alias.<\/p>\n\n\n\nThe behavior is simple but effective:<\/p>\n\n\n\n
\n- If the requested URL is available<\/strong>, the response contains exactly the same URL<\/strong><\/li>\n\n\n\n
- If the URL is not available<\/strong> (because it already exists or is soft-deleted), SharePoint returns a modified URL<\/strong>, usually with a number appended (for example, mySite2)<\/li>\n<\/ul>\n\n\n\n
While this is not the most elegant solution, it gives us a reliable signal:<\/p>\n\n\n\n
If the returned URL differs from the requested one, the original URL is not available.<\/strong><\/p>\n\n\n\nMost importantly, this mechanism takes soft-deleted sites into account<\/strong>, making it far more reliable than checking site existence via REST.<\/p>\n\n\n\nSummary<\/h2>\n\n\n\n
Checking whether a SharePoint site URL is available is trickier than it looks:<\/p>\n\n\n\n
\n- Simply calling the site REST API and checking for 404 is not sufficient<\/strong><\/li>\n\n\n\n
- Soft-deleted sites block URLs for up to 93 days<\/strong><\/li>\n\n\n\n
- The GroupSiteManager.GetValidSiteUrlFromAlias endpoint provides a practical and reliable way<\/strong> to validate URL availability before site creation<\/li>\n<\/ul>\n\n\n\n
If you are building custom provisioning solutions, request forms, or automated intranet tooling, this extra validation step can save you from unexpected provisioning failures \u2014 and confused users.<\/p>\n","protected":false},"excerpt":{"rendered":"
The problem When working on intranet solutions in SharePoint, a very common scenario is allowing users to create new sites \u2014 or at least request them through a form or custom application. In such cases, users are often asked to provide the site URL suffix \u2014 the part that comes after: https:\/\/tenant.sharepoint.com\/sites\/\u2026 Before creating a […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[4],"tags":[],"class_list":["post-31","post","type-post","status-publish","format-standard","hentry","category-sharepoint"],"_links":{"self":[{"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/posts\/31","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/comments?post=31"}],"version-history":[{"count":3,"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/posts\/31\/revisions"}],"predecessor-version":[{"id":36,"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/posts\/31\/revisions\/36"}],"wp:attachment":[{"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/media?parent=31"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/categories?post=31"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/tomaszwojtasik.com\/index.php\/wp-json\/wp\/v2\/tags?post=31"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}