Heroku Custom Domain SSL Certificate Not Working

How to fix it

Try these in order — the most common fix is first.

1. 1. Use the right DNS target

   Copy steps
   1. Run heroku domains -a <app> and copy the DNS target (name.herokudns.com)
   2. Create a CNAME for www, and ALIAS/ANAME for the root domain
   3. Do not use A records; Heroku has no static IPs
   Did this fix it? Yes No

2. 2. Add each domain

   1. heroku domains:add example.com and heroku domains:add www.example.com separately
   Did this fix it? Yes No

3. 3. Check ACM status

   Copy steps
   1. Run heroku certs:auto -a <app>
   2. Issuance usually takes 45-60 minutes
   3. After fixing DNS run heroku certs:auto:refresh
   Did this fix it? Yes No

4. 4. Allow Let's Encrypt in CAA

   1. If you have CAA records, add: example.com. CAA 0 issue "letsencrypt.org"
   Did this fix it? Yes No

5. 5. Check for CDN or proxy conflicts

   Copy steps
   1. Point DNS straight at Heroku while the certificate is issued
   2. With Cloudflare strict TLS, disable ACM (heroku certs:auto:disable) and use Cloudflare certificates
   Did this fix it? Yes No

6. 6. Do not toggle ACM repeatedly

   1. Repeated enable/disable can trigger the Let's Encrypt rate limit for 7 days
   Did this fix it? Yes No

Symptoms

Browser warns the certificate is invalid, heroku certs:auto shows Failing/Failed, or the domain does not load.

Why it happens

• DNS points to app.herokuapp.com instead of the herokudns.com target
• A record used on the apex domain
• CAA record blocks Let's Encrypt
• Domain behind a CDN or Cloudflare proxy
• DNS not propagated yet
• Let's Encrypt rate limit after toggling ACM

This guide also covers

• heroku custom domain ssl not working
• heroku acm certificate pending
• heroku certs:auto failing
• heroku ssl certificate error

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• Heroku H12 Request Timeout Error
• Heroku R14 Memory Quota Exceeded Error
• Heroku Application Error Page
• Heroku Build Failed Error
• Heroku Git Push Rejected / Remote Rejected
• Heroku H14 No Web Dynos Running
• Heroku R10 Boot Timeout / H20 App Boot Timeout