HTTP vs HTTPS explained simply

HTTP vs HTTPS explained simply

This article is a step-by-step tutorial that explains the practical differences between HTTP and HTTPS and shows how to move a website from unsecured HTTP to encrypted HTTPS in a controlled way.

Step 1 — understand the difference and why it matters. HTTP is the original protocol used to transfer web pages and resources, and it sends data in plain text which makes it easy for third parties to read or tamper with requests and responses. HTTPS adds a TLS layer to encrypt the connection between the browser and the server, which protects confidentiality and integrity and helps prevent man-in-the-middle attacks, while also providing a way for a browser to verify the identity of the server.

Step 2 — check your current site and identify scope. Use a browser to look for the padlock and the security information it shows, and open the developer console to find any mixed content warnings where an HTTPS page loads HTTP resources. Inspect server responses to confirm whether requests to port 80 redirect to port 443 and whether cookies use the Secure attribute. Note which domains and subdomains you must secure so you can request certificates that cover every relevant name.

Step 3 — obtain a certificate and prepare for installation. You can choose a free certificate authority such as Let’s Encrypt or a paid certificate from a commercial CA, or you can obtain certificates through your hosting panel which often automates the process. If you use an ACME client like certbot you will request a certificate for each domain and the client will perform domain validation for you, or you can create a CSR and submit it to your chosen CA if you prefer manual control.

Step 4 — install the certificate and update server configuration. On typical web servers you will place the certificate and private key in a secure location and point the server configuration to the full chain and key files. Test the configuration with a syntax check and then reload or restart the web server to apply changes. After the site serves HTTPS correctly, configure a permanent 301 redirect from HTTP to HTTPS for all requests and ensure cookies use Secure and SameSite attributes where appropriate, while being cautious about enabling HSTS until you are confident there are no broken subdomains.

• Confirm the padlock appears and the certificate details match the domain names you expect.
• Scan pages for mixed content and update or host those resources over HTTPS.
• Verify HTTP responses are redirected to HTTPS with a single 301 redirect where appropriate.
• Check that the certificate chain is complete and that intermediate certificates are served where required.
• Note the certificate expiry date and plan for renewal well before that date.

Step 5 — automate renewal and add monitoring. If you used an ACME client, enable automatic renewal and confirm that the renewal job can restart or reload the web server when necessary, for example using a cron job or a systemd timer. If you opted for a paid certificate, set calendar reminders and consider a monitoring alert that warns you when expiry is approaching. Also include periodic checks of your public configuration and mixed content status so that future deployments do not inadvertently revert to HTTP resources.

Final checks and maintaining confidence in HTTPS. After implementation, review any external integrations, API endpoints and third-party widgets to ensure they work over HTTPS, and consider a staged rollout for more complex infrastructures. If you would like more practical infrastructure guides and related tutorials, see the Infrastructure posts on this site for further reading and follow-up steps. For more builds and experiments, visit my main RC projects page.