What is a Wildcard SSL Certificate?
Last Updated: August 20, 2025
A Wildcard SSL Certificate is a single digital certificate that secures a primary domain (e.g., yourdomain.com) and all of its first-level subdomains (e.g., blog.yourdomain.com, shop.yourdomain.com, mail.yourdomain.com). It does this using a wildcard character (*) in the Subject Alternative Name (SAN) field, typically formatted as *.yourdomain.com. It, however, does not secure the root domain (yourdomain.com) unless explicitly added as a SAN.
Instead of purchasing and managing separate certificates for each subdomain, a Wildcard SSL consolidates protection under one certificate. This simplifies management, lowers costs, and still delivers the same industry-standard encryption which uses mandatory 256-bit TLS (AES-256 or equivalent). The strength is identical to non-wildcard certificates.
How Wildcard SSL Certificates Work
The Wildcard Mechanism
The asterisk * acts as a dynamic placeholder, automatically securing all existing and future first-level subdomains.
- Example: *.example.com secures store.example.com and support.example.com.
- Limitation: It does not secure second-level subdomains such as dev.blog.example.com.
Encryption functions identically to standard SSL/TLS certificates, with the same TLS handshake and cryptographic processes.
Validation Levels
Wildcard SSLs are available in two validation types:
1. Domain Validation (DV):
- Confirms domain ownership via DNS, email, or HTTP/HTTPS file-based validation.
- Fast issuance (minutes to a few hours).
- Best for internal sites, development environments, blogs, personal sites, or non-transactional pages.
2. Organization Validation (OV):
- Requires verification of legal business existence (registration, address, phone).
- Issued in 1–5 days (may vary by CA).
- Displays organization details in the certificate for added trust.
Note: Wildcard SSLs are not issued at Extended Validation (EV) level, due to industry policies that require stricter, per-domain vetting.
Key Benefits of Wildcard SSL Certificates
- Cost Efficiency
- Protect unlimited subdomains under a single domain with a one certificate.
- Example: One $120/year Wildcard cert replaces 10+ separate single-domain certs ($300+).
- Simplified Management
- One certificate covers all subdomains. This streamlines installation, renewals, and expirations.
- New subdomains are included automatically, without reissuing the certificate.
- Unified Security
- Consistent encryption across every subdomain, reducing risk of configuration mismatches.
- SEO & Trust Advantages
- HTTPS improves Google search rankings.
- Prevents “Not Secure” browser warnings across all subdomains.
Best Practices
- Use Wildcards for non-critical subdomains (ex: blogs, support portals).
- For financial transactions or login portals, use dedicated OV/EV certificates.
KnownHost’s Wildcard SSL Offerings
We partner with top Certificate Authorities (Sectigo, RapidSSL, GeoTrust) to deliver both budget-friendly and enterprise-grade options. Our wildcard ssl offerings are as follows:
Domain Validated (DV) Wildcards
- Sectigo PositiveSSL Wildcard: $120/year – Protects Single domain, $10K warranty.
- RapidSSL Wildcard: $150/year – 256-bit encryption, 99% browser compatibility, $10K warranty.
Organization Validated (OV) Wildcards
- Sectigo InstantSSL Premium Wildcard: $200/year – Business validation + $250K warranty.
Free Alternative: KnownHost’s AutoSSL (powered by Let’s Encrypt) issues free DV Wildcards via cPanel for hosted domains.
Implementation Guide: Setup in 4 Steps
- Generate CSR – In cPanel, create a Certificate Signing Request with *.yourdomain.com as the Common Name.
- Purchase/Activate – Choose a Wildcard certificate via KnownHost’s SSL portal or enable free AutoSSL.
- Install – Navigate to cPanel ? SSL/TLS ? Install Certificate. Upload CA-issued files.
- Verify – Use SSL testing tools (e.g., SSL Labs) to confirm subdomain coverage.
Wildcard vs. Alternatives: Which SSL Should You Choose?
| Solution | Best For | Limitation |
| Wildcard SSL | Sites with frequent/dynamic subdomain growth | No EV option; higher single-key risk |
| Multi-Domain (SAN) | Fixed set of domains (e.g., site.com, app.net) | Higher cost per domain |
| Single SSLs | High-risk, critical pages (checkout, login) | Greater management complexity |
Why Choose KnownHost?
- 24/7 SSL Support: Guidance for installation, renewals, and troubleshooting.
- Transparent Pricing: Competitive multi-year discounts and zero hidden fees.
- Seamless Hosting Integration: SSL deployment optimized for KnownHost VPS.
Final Thoughts: Balance Convenience with Security
Wildcard SSL certificates deliver unmatched efficiency for managing multiple subdomains under one umbrella. They’re ideal for fast-growing businesses, SaaS platforms, and content-heavy enterprises, but should be paired with best practices and additional OV/EV certs for sensitive workflows.