DevOps Featured

Some Let's Encrypt Facts

The Tran

12 Th09 2023 • 1 min read

Photo by The Climate Reality Project / Unsplash

Time validity

Certificates issued by LE are valid for 90 days.

SAN (Subject Alternate Name)

A certificate contains up to 100 domain names in SAN list. The domain names map directly into names of servers, as sub-domain wildcards are not allowed.

Wildcard support

Wildcard certificates are available from March 2018 with DNS validation.

Supported algorithms

RSA keys, with lengths 2048, 3076, or 4096
P-256 ECDSA keys
P-384 ECDSA keys.

Max certificates request limit

50 certificates per week per registered domain. This is a soft limit. You can request to increase the limit, but please don't always expect a positive outcome!

Renewals (which contain exactly the same set of domains) are not counted into this limit, even if the existing certificate already expired.

💡

Staging/test environment has the limit of 30,000 certificates per domain per week.

Renewal limits

5 renewals per week per certificate. A request for a certificate is counted as a renewal, if it contains exactly the same set of domain names.

Note:

Domain names are case insensitive
Domain names can be in any order.

💡

The staging/test environment has a limit of 50,000 renewals per account per week.

Update domains of an existing certificate

Changing the set of domain names (add new domains, remove domains, modify domains) will be counted as a new certificate request.

Certificate request steps

The steps are:
1. Authorization request
2. Providing a proof of domain ownership
3. Certificate issuance.

These steps should be completed within 7 days. LE implemented two different time limits:

7 days - to complete step 2
30 days (currently) - to complete step 3