Open port checker
Check whether a TCP port answers from the internet, like 443 for a website, 22 for SSH or 5432 for PostgreSQL.
Good to know
- Closed or filtered?
- Closed means the server answered but nothing listens on that port. Filtered means no answer at all, usually a firewall dropping the connection.
- Should my database port be open?
- Usually not. Databases like MySQL (3306), PostgreSQL (5432), Redis (6379) and MongoDB (27017) should only accept connections from your own servers.
- Keep an eye on a port
- Spot Downtime's TCP monitors check a port around the clock and alert you when it stops answering.
Get told the moment it breaks
Checking by hand only tells you about right now. Spot Downtime checks your sites around the clock and alerts you by email, Slack or Discord.
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