Umbraco sells extended support for version 13 in 6, 12, or 24-month blocks - but does not publish the price. Here is the full cost of each route: the XLTS fee structure and what it quietly excludes, versus what an upgrade to 17 actually involves.
WordPress runs about 41% of the web, and its core is not the security problem people claim - 91% of WordPress vulnerabilities sit in plugins. That reframes the whole question: you are not picking a CMS, you are picking a dependency model. Here is when each one is the right call.
Technical SEO is not a package you install afterwards - it is decided in the architecture. Ten points I build every Umbraco solution to: canonical, hreflang, sitemaps, structured data, status codes, performance, and the mistakes I meet most often in existing solutions.
Every Umbraco project started with the same weeks of foundation work: SEO plumbing, security headers, accessibility groundwork, block architecture. After enough repetitions the conclusion was obvious: solve it once, properly, and stop billing clients for solved problems.
Umbraco 13 will reach End of Life on December 14, 2026. The underlying .NET 8 platform will reach the end of Microsoft support even earlier, on November 10, 2026.
Your website will not suddenly stop working when these dates pass. However, regular security updates and support will cease, making the solution increasingly difficult and risky to maintain.
Organizations using Umbraco 13 should therefore evaluate their upgrade options well in advance of the end dates, rather than waiting until a security issue or change in the operating environment forces an emergency migration.