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# #TIL - ZeroSSL
- URL: https://muratcorlu.com/til-zerossl/
- Published: 2024-02-19T15:34:39.000Z
- Updated: 2024-04-05T22:45:17.000Z
- Author: Murat Çorlu
- Tags: Today I Learned

[Free SSL Certificates and SSL Tools - ZeroSSLFree SSL certificates issued instantly online, supporting ACME clients, SSL monitoring, quick validation and automated SSL renewal via ZeroSSL Bot or REST API.![](https://zerossl.com/assets/images/zerossl_icon.png)ZeroSSL LogoZeroSSL![](https://zerossl.com/assets/images/zerossl_logo.svg)](https://zerossl.com/?fpr=muratcorlu&ref=muratcorlu.com)

I use LetsEncrypt for all of my projects since a while. But this week I learned that, LetsEncrypt has a limit of 50 domain certificates generation per week. 

> The main limit is **Certificates per Registered Domain** (50 per week). A registered domain is, generally speaking, the part of the domain you purchased from your domain name registrar. For instance, in the name `www.example.com`, the registered domain is `example.com`.  
> [https://letsencrypt.org/docs/rate-limits/](https://letsencrypt.org/docs/rate-limits/?ref=muratcorlu.com)

This is still a generous number but if you consider to provide a SaaS with custom domain support, you would need to consider a solution. ZeroSSL can be a good drop-in replacement for LetsEncrypt since it also supports ACME clients. So it works with Traefik, that was important to me. And $8/m for basic requirements seems like a fair pricing.

### EDIT (5 April 2024):

I wanted to try ZeroSSL buy subscribing their Basic Plan. When I enabled on my Traefik Server, I immediately started getting "429 Too Many Requests" errors from their server. They don't mention any rate limits anywhere and I only tried to issue certificates for a few domains. Then I noticed that this seems like a common problem on ZeroSSL. Check this GitHub Issue: 

[Controller can’t handle hitting request rate limits of zerossl ACME API · Issue #5867 · cert-manager/cert-managerDescribe the bug: We’ve been using cert-manager with zerossl as ACME provider using http01 challenges for several months now vey successfully. However, since a couple of weeks ago, zerossl must hav…![](https://github.githubassets.com/assets/pinned-octocat-093da3e6fa40.svg)GitHubcert-manager![](https://opengraph.githubassets.com/7e8e50eee5a89e5aa5b4e74e39a6e2e8ce1be6aab4f17f307b7235111704f59c/cert-manager/cert-manager/issues/5867)](https://github.com/cert-manager/cert-manager/issues/5867?ref=muratcorlu.com)

So, please be cautious for using ZeroSSL to avoid LetsEncrypt's rate limits. You can consider using [Google Cloud's ACME](https://cloud.google.com/blog/products/identity-security/automate-public-certificate-lifecycle-management-via--acme-client-api?ref=muratcorlu.com).