A self-signed certificate is a type of digital certificate that’s signed by the entity creating it rather than a trusted certificate authority (CA). In simple terms, it's like creating your own ID badge instead of getting one issued by a recognized authority. These certificates are most commonly used in development environments or internal networks, where trust is already established and cost-saving is a priority.

While they can offer encryption and authentication just like CA-issued certificates, self-signed certificates don't provide third-party validation, which can raise trust issues for public-facing websites. That's why they're generally not recommended for live websites meant for external users.

How does a self-signed certificate work

When you generate a self-signed certificate, your server essentially acts as both the issuer and the subject. It uses its own private key to sign its certificate file. This still allows for encrypted communication, but because there's no outside authority verifying its legitimacy, browsers may throw up warning messages indicating the connection isn’t secure.

Where are self-signed certificates commonly used

Self-signed certificates are useful for internal testing, local development, and intranet applications. Developers often use them to simulate secure connections before launching a website live with a proper CA-issued certificate.

For example, if you’re testing how your site handles HTTPS before going live, a self-signed certificate does the trick. They're quick to create, cost nothing, and still offer SSL/TLS-level encryption.

Why don’t browsers trust self-signed certificates

Browsers and operating systems rely on a list of trusted certificate authorities. Since self-signed certificates aren’t signed by any of these trusted parties, browsers treat them as suspicious. That’s why you might see a scary-looking warning when visiting a site that uses one. It doesn’t necessarily mean the site is malicious—it just hasn’t been validated by a trusted third party.

Should I use a self-signed certificate on my live site

If your goal is to create trust, improve SEO rankings, and support secure communication with your customers, then no—a self-signed certificate isn’t the way to go. You’ll want a certificate from a trusted CA. But for quick internal setups or early-stage development, self-signed can be a helpful tool.

FAQs about self-signed certificate

Can I use a self-signed certificate with a custom domain?

Yes, you can, but expect browser warnings unless users manually accept your certificate. It’s not ideal for public access.

How do I create a self-signed certificate?

You can generate one using tools like OpenSSL. The process typically involves generating a private key and then creating a certificate signed by that key.

Are self-signed certificates encrypted?

Yes, they use the same encryption protocols as CA-signed certificates. The lack of trust comes from identity verification, not encryption.

Do self-signed certificates expire?

Yes. Like CA-issued certificates, self-signed ones have an expiration date. You’ll need to regenerate and reapply them periodically.

Can I convert a self-signed certificate to a CA-signed one?

Not directly. You’d need to request a new certificate from a certificate authority and go through their validation process.

How self-signed certificates fit into web design

For most live and public-facing projects, you’ll want to steer clear of self-signed certificates because of the trust and browser issues. But if you’re working in a sandbox or building with an AI website builder like B12, self-signed certificates can still play a useful role during development. They’re a budget-friendly way to test HTTPS setups or internal tools before applying for a verified certificate. When you're ready to move from staging to live, consider upgrading to a CA-signed certificate for better reliability and user trust.

If you're aiming to boost your client engagement or start email marketing campaigns that require secure forms and user interactions, proper SSL via trusted certificates is key. Whether you’re launching a blog, generating content, or offering online scheduling, your certificate matters.

Ready to build securely and smartly? Get started with B12 today.