Website Validation

Here is a list of the online tools I use, which might be helpful for you to find out if your website is without bugs or if it has some greater problems. Have fun and take a look at your own website.

Last updated November 11, 2019.

During my development at Blogless and mobiki I came across the question in many areas whether I am doing everything right. Sometimes you think you've understood everything, but it's always good to see if a programming or approach is really correct. Are all HTML tags correct, is my CSS stylesheet correct, does my international language version “hreflang” match?

Generic online validation tools

Specific validation tools for metadata

Validation regarding security

  • Observatory of Mozilla - checks your website for security
  • CSP Analysis by Report Uri - analyzes and builds a content security policy for you
  • SSL Server Test from Qualsys SSL Labs - Check your SSL Settings
  • Hardenize - Checks your web server and several DNS settings
  • hstspreload.org - checks if your domain is configured correctly for HSTS
  • WebSec - Test your Content Security Policy (CSP), HTTP Security Headers and Web Server Security

Speed and other tools

Mail Server Validation


I will add to this list as soon as I encounter more cool tools