How to Fix an SSL Certificate Between IONOS and WordPress

When you open your WordPress website and suddenly see a “Not Secure” warning in the browser, it can be alarming. Even worse, visitors may leave immediately, forms may stop working, and Google rankings can drop.

If your website is hosted on IONOS and powered by WordPress, SSL issues are more common than many beginners expect—but the good news is that they are also very fixable.

This beginner-friendly guide explains how to fix an SSL certificate between IONOS and WordPress, what causes these problems, and how to prevent them in the future—without deep technical knowledge.

What Is an SSL Certificate and Why It Matters

SSL (Secure Sockets Layer) certificates encrypt data transferred between a user’s browser and your website. When SSL is working correctly, visitors see:

• A padlock icon in the browser
• An https:// prefix in the URL
• Trust signals that protect login credentials, contact forms, and payments

Without SSL, browsers warn users that your site is unsafe—even if nothing malicious is happening.

For WordPress websites, SSL is no longer optional. Google uses HTTPS as a ranking signal, and most modern browsers actively discourage users from interacting with non-secure sites.

Why SSL Issues Often Happen Between IONOS and WordPress

IONOS provides SSL certificates at the hosting level, while WordPress controls how URLs, assets, and internal links are loaded. Problems occur when these two systems are not perfectly synchronized.

Common causes include:

• SSL activated in IONOS, but not configured in WordPress
• Mixed content (some files still loading via HTTP)
• Incorrect WordPress Address or Site Address
• Caching or CDN conflicts
• SSL installed on one domain version but not others

Understanding these root causes makes fixing the problem much easier.

Step 1: Confirm That SSL Is Active in IONOS

Before touching WordPress, always start at the hosting level.

Log in to your IONOS dashboard and check:

• Is an SSL certificate assigned to your domain?
• Is it active and not expired?
• Does it cover the correct domain (with or without “www”)?

IONOS usually offers free SSL certificates, but activation is not always automatic. If SSL is not enabled here, WordPress cannot use it properly.

Once SSL is confirmed active in IONOS, move on to WordPress.

Step 2: Update WordPress Site URLs to HTTPS

One of the most common reasons people search how to fix an SSL certificate between IONOS and WordPress is simply because WordPress is still using HTTP internally.

In your WordPress dashboard:

1. Go to Settings → General
2. Update both fields:
   • WordPress Address (URL)
   • Site Address (URL)
3. Change http:// to https://
4. Save changes and log back in

This tells WordPress to load all core pages securely.

Step 3: Fix Mixed Content Errors (Very Common)

Even after enabling HTTPS, your browser may still show a “Not Secure” warning. This usually means mixed content.

Mixed content happens when:

• The page loads via HTTPS
• But images, scripts, or stylesheets still load via HTTP

Browsers block or warn against this behavior.

How to Identify Mixed Content

Open your website in Chrome, right-click, and choose Inspect.
Look for warnings like:

“Blocked loading mixed active content”

These messages show exactly which files are still using HTTP.

Step 4: Automatically Replace HTTP URLs in WordPress

For most WordPress users, the fastest fix is using a plugin.

Popular options include:

• Really Simple SSL
• Better Search Replace
• WP-CLI (for advanced users)

A plugin like Really Simple SSL automatically:

• Detects SSL
• Updates internal URLs
• Forces HTTPS
• Fixes common mixed content issues

This is often the simplest solution for beginners.

Step 5: Force HTTPS via .htaccess (Optional but Powerful)

If your site still loads both HTTP and HTTPS versions, forcing HTTPS at the server level ensures consistency.

Add this rule to your .htaccess file:

RewriteEngine On
RewriteCond %{HTTPS} !=on
RewriteRule ^ https://%{HTTP_HOST}%{REQUEST_URI} [L,R=301]

This permanently redirects all traffic to HTTPS, helping both SEO and security.

Always back up your site before editing .htaccess.

Step 6: Clear Cache and CDN Layers

Caching can make SSL fixes appear broken—even when they are not.

After making changes:

• Clear WordPress cache
• Clear IONOS cache (if enabled)
• Clear CDN cache (Cloudflare, etc.)
• Refresh browser cache or use Incognito mode

Many SSL issues are simply old cached files.

Step 7: Check Domain Variations (www vs non-www)

IONOS SSL certificates may cover:

• example.com
• www.example.com
  …but WordPress might be using the other version.

Make sure:

• SSL covers all domain variations
• WordPress URLs match the SSL-protected version
• Redirects are consistent

Inconsistent domain versions are a silent but common cause of SSL errors.

Step 8: Test Your SSL Setup Properly

After fixing everything, test your site using:

• Browser padlock
• Incognito mode
• Online SSL testing tools

Check:

• No mixed content warnings
• No redirect loops
• HTTPS works on all pages, not just homepage

A properly configured SSL setup should feel invisible to users.

Common SSL Errors Between IONOS and WordPress (Explained Simply)

Here are issues people often encounter:

• “Too many redirects”
  Usually caused by conflicting HTTPS rules between WordPress, plugins, and server settings.
• “Your connection is not private”
  Often appears when SSL is expired, misassigned, or not fully propagated.
• Padlock missing on some pages
  Indicates mixed content inside posts or theme files.

Each of these has a logical cause—and a fix.

How to Prevent SSL Problems in the Future

Once SSL is fixed, prevention matters.

Best practices:

• Always activate SSL before launching a site
• Use HTTPS from day one
• Avoid hard-coded HTTP links in themes
• Keep plugins and themes updated
• Use consistent domain settings

SSL problems usually return when websites grow, migrate, or change hosts without a clear plan.

Final Thoughts: SSL Is More Than a Technical Detail

Learning how to fix an SSL certificate between IONOS and WordPress is not just about removing browser warnings.

It’s about:

• User trust
• SEO performance
• Conversion rates
• Brand credibility

For cross-border websites especially, SSL is a basic expectation. Visitors from different countries are even more sensitive to security signals.

At AIRSANG, this is exactly the kind of work we handle every day—helping global businesses build secure, high-performance WordPress websites that are ready for international markets. From website design to technical setup and long-term optimization, we make sure your site is not only beautiful, but reliable and trustworthy.

If you’re dealing with SSL issues—or planning a cross-border WordPress website—we’re always happy to help.