Web development and performance
What is HTTPS?
HTTPS encrypts traffic between browser and server using TLS. It is required for browser features, expected by users, and a lightweight ranking signal — but its real value is that without it, everything transmitted is readable and modifiable in transit.
Also called: TLS · SSL certificate
Getting it right, not merely on
- HTTP redirects to HTTPS in one hop, not through www and back
- HSTS enabled so the browser refuses to downgrade
- No mixed content — a single http:// asset undermines the whole page
- Certificate renewal automated, because manual renewal is a diary entry somebody eventually misses
The failure that costs the most
An expired certificate produces a full-page browser interstitial that stops every visitor. It is entirely preventable with automated renewal and monitoring, and it is one of the most common ways a small business site goes dark without anyone noticing for days.
Cost
Free. Let’s Encrypt has issued free certificates with automated renewal for a decade, and every serious host supports it. Paying for a basic certificate buys nothing technical.
Where this is covered in depth
A definition can only go so far. Technical SEO, in the order the problems actually block you covers this properly — 4 minutes, free, no email required.
Who wrote this
Anas Bin Masud builds e-commerce sites and does technical SEO for businesses in the UK, Canada and Pakistan. These definitions come from client work rather than from a content brief — where an entry describes a mistake, it is usually one found on a real site. More about how I work.