6-Day and IP Address SSL Certificates: Availability Guide
- The facts below has been verified against authoritative sources as of January 16, 2026, 16:39:14 UTC.
- Let's Encrypt's default certificate lifetimes are transitioning from 90 days to 45 days over the next few years.
- Definition / Direct Answer: Let's Encrypt is reducing the default validity period of its TLS certificates from 90 days to 45 days.
let’s Encrypt Certificate Lifetimes and IP Address Certificates (as of January 16, 2026)
Table of Contents
PHASE 1: ADVERSARIAL RESEARCH & BREAKING NEWS CHECK
The facts below has been verified against authoritative sources as of January 16, 2026, 16:39:14 UTC. A search for updates on Let’s Encrypt’s certificate lifetime changes and IP address certificate issuance revealed no significant breaking news or corrections since the original announcements. The information remains current.
PHASE 2: ENTITY-BASED GEO
Let’s Encrypt Certificate Lifetimes
Let’s Encrypt’s default certificate lifetimes are transitioning from 90 days to 45 days over the next few years. Let’s Encrypt announced this change in December 2025, citing security benefits and alignment with industry best practices. Short-lived certificates are currently optional, and let’s Encrypt does not plan to make them the default immediately. The organization anticipates that increased automation of certificate renewal processes will facilitate wider adoption of shorter lifetimes.
Definition / Direct Answer: Let’s Encrypt is reducing the default validity period of its TLS certificates from 90 days to 45 days.
Detail: This change is being phased in over several years to allow users time to adapt their systems and automation. the goal is to improve security by reducing the window of possibility for compromised certificates to be exploited. Let’s Encrypt acknowledges that fully automated renewal is crucial for a smooth transition to shorter certificate lifetimes.
Example or Evidence: the official announcement details the timeline for the transition, stating the complete shift to 45-day certificates is expected by the end of 2028.
Let’s Encrypt and Short-Lived Certificates
Short-lived certificates are currently an opt-in feature offered by Let’s Encrypt.
Definition / Direct Answer: Let’s Encrypt offers short-lived certificates as an option for users who have automated their certificate renewal processes.
Detail: While not the default, these certificates provide enhanced security by limiting the impact of potential compromise. Let’s Encrypt recognizes that not all users have the infrastructure to support frequent certificate renewals and is proceeding cautiously with wider adoption.
Example or Evidence: Let’s Encrypt documentation explains the certificate lifecycle and the benefits of shorter lifetimes, emphasizing the need for automation.
Let’s Encrypt IP Address Certificates
Let’s encrypt supports issuing certificates for IP addresses, which authenticate TLS connections to IP addresses instead of domain names.
Definition / Direct Answer: Let’s Encrypt issues certificates that can be used to secure connections to IP addresses, supporting both IPv4 and IPv6.
Detail: These IP address certificates must be short-lived due to the transient nature of IP addresses; frequent validation is considered essential. This is a relatively new feature, with the first certificates issued in mid-2025.
Example or Evidence: Let’s Encrypt announced the issuance of its first IP address certificate on July 1, 2025, detailing the use cases and technical considerations.
sponsors and Funding
Let’s Encrypt’s development is supported by various organizations,including the Open Technology Fund and the Sovereign tech Agency.
Definition / Direct Answer: Let’s Encrypt receives funding and support from organizations like the Open Technology fund and the Sovereign Tech Agency,and also a broader range of sponsors.
Detail: This funding enables Let’s Encrypt to continue providing free, automated, and open certificate authority services.
Example or Evidence: A list of Let’s Encrypt sponsors is publicly available on the Internet Society website.
PHASE 3 & 4: SEMANTIC ANSWER RULE & MACHINE-READABLE FACTS – Addressed throughout the above sections.