I can connect but my friends can't (or vice versa) — why?

When a server works for one person but not another, the server itself is fine — the difference is on the client side. That narrows things down to a handful of easy checks.

Why it's client-side

If the server were down or misconfigured, nobody would get in. Since you can connect, the process is running and reachable; the person who can't is hitting a mismatch on their end.

What to check

Make sure everyone uses the same IP:port or domain, copied exactly.
Check they're on a matching Minecraft version.
If some are on Bedrock, they need the Bedrock/Geyser port and the IP and port in separate fields.
Have them try a different network — some school, office, or mobile networks block game ports.

Tip: If only Bedrock players fail, it's a crossplay/port setup issue — see the Geyser articles.

Frequently asked questions

We're all on the same address and version — still blocked. Have the affected player switch networks (mobile hotspot is a quick test). Restrictive networks are a common cause.

Only I can't connect but everyone else can. Flush your local DNS and confirm you copied the address exactly, then retry.