In December 2015, the non-profit organization Internet Security Research Group launched the Let’s Encrypt initiative, a free and automated SSL/TLS certificate authority. The project was supported by major technology organizations, including Mozilla, Cisco, and Facebook.
The goal of Let’s Encrypt was simple: make website encryption free, accessible, and easy to deploy for everyone.
Today, Let’s Encrypt is one of the most widely used certificate authorities in the world and has helped make HTTPS the standard across the internet.
Table of Contents
What Is Let’s Encrypt?
Let’s Encrypt provides free SSL/TLS certificates that allow websites to use:
https://instead of:
http://When a website uses HTTPS, communication between the visitor’s browser and the web server is encrypted.
This helps protect:
- Login credentials
- Contact form submissions
- Personal information
- Payment data
- Session cookies
from being intercepted by unauthorized parties.
Is Let’s Encrypt Secure?
Yes.
The level of encryption provided by a Let’s Encrypt certificate is the same as that provided by most commercial SSL certificates.
A free certificate does not mean weaker encryption.
The primary differences between Let’s Encrypt and commercial certificates are related to:
- Validation methods
- Warranty programs
- Extended business verification options
What Type of Certificate Is Let’s Encrypt?
Let’s Encrypt issues:
DV (Domain Validation) certificatesA DV certificate verifies that the applicant controls the domain name.
For example:
yourdomain.comThe certificate authority confirms domain ownership and then issues the certificate.
What Types of Certificates Are Not Available?
Let’s Encrypt does not issue:
OV Certificates
Organization ValidationThese require verification of the company or organization requesting the certificate.
EV Certificates
Extended ValidationThese require extensive verification of the business entity and may display additional company information depending on browser support.
Certificate Validity Period
Unlike many commercial SSL certificates that are issued for one year or longer, Let’s Encrypt certificates are valid for:
90 daysHowever, most hosting providers automate the renewal process.
As a result, users typically do not need to manually renew the certificate every 90 days.
How Does Let’s Encrypt Work?
When a visitor opens a website secured with SSL/TLS:
1. Browser Connects to the Website
The visitor enters:
https://yourdomain.com2. Certificate Is Presented
The web server sends its SSL certificate to the browser.
3. Certificate Validation
The browser checks:
- Whether the certificate is valid.
- Whether it was issued by a trusted certificate authority.
- Whether it matches the requested domain.
- Whether it has expired.
4. Secure Connection Is Established
If validation succeeds, the browser establishes an encrypted connection with the server.
5. Data Is Encrypted
All information exchanged between the browser and server is transmitted in encrypted form.
This helps prevent eavesdropping and data tampering.
Why Is HTTPS Important?
HTTPS is especially important for websites that:
- Allow user logins
- Process online orders
- Collect personal information
- Accept payments
- Provide customer portals
Modern browsers may display security warnings for websites that do not use HTTPS.
Benefits of Let’s Encrypt
- Free SSL certificates
- Strong encryption
- Automated issuance and renewal
- Trusted by major browsers
- Improves website security
- Enables HTTPS support
- Helps build visitor trust
Summary
Let’s Encrypt is a free certificate authority that provides DV SSL/TLS certificates for websites.
Certificates are valid for 90 days, but renewal is usually handled automatically by the hosting provider. Once installed, the certificate allows a website to use HTTPS and encrypt communication between visitors and the server, helping protect sensitive information from interception and unauthorized access.