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How to check if your game server's port is open from your phone

Open Port Scanner in the RCON app, type the server's Hostname or IP, pick a Preset such as Minecraft or Rust (or type your own ports), and start the scan. Each port comes back Open, Closed or Filtered, and an open one also shows how long the connection actually took.

3 min read · Updated 2026-09-15

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Why the port is the first thing to check

Friends cannot join, or the RCON console refuses to connect. Either way the first real question is whether the port can be reached at all, and the answer tells you exactly where to look next, router and firewall on one side, server software on the other. It takes seconds from your phone, and running it over mobile data instead of home Wi-Fi shows you what players outside your network actually see.

Running the scan

  1. On Servers, tap the terminal button in the top bar and choose Port Scanner under Tools.
  2. Type the server's public address or domain into Hostname or IP.
  3. Choose a Preset for your game, or type ports into Custom ports (e.g. 80,443,8080-8090). Typing custom ports replaces whatever preset was selected.
  4. Start the scan, and results trickle in as each port answers; Stop Scan cuts it short whenever you have enough.
  5. Read what comes back: an open port shows its connect time in milliseconds right next to it.

The presets already built in

Ports each preset scans
PresetPorts
RCON Ports25575, 27015, 28016
Minecraft25565, 25575, 19132
Rust28015, 28016, 28082
ARK7777, 7778, 27015, 27020
Counter-Strike27015, 27016, 27017
Valheim2456, 2457, 2458
Terraria7777
Factorio34197
Common Services21, 22, 23, 25, 53, 80, 443, 3306, 5432, 8080, 8443

Reading Open, Closed and Filtered correctly

Reading a port scan
ResultWhat happenedWhat to check
OpenA program accepted the connectionThe port is fine; if the game still fails, look at the server settings or password
ClosedThe machine answered but refused the connectionNothing is listening: the server is down, or it listens on another port
FilteredNo answer within 3 secondsA firewall, router or missing port forward is dropping the traffic

This exact pattern shows up more than any other: scan 25565 from home and it comes back Open, scan the same port over mobile data against your public address and it shows Filtered. Nothing wrong with the server itself, the router just is not forwarding that port, classic Minecraft port forwarding not working, every time.

Where TCP-only trips you up

The scanner only tests TCP, that is the one limit worth saying plainly up front. Several games run players over UDP instead, Valheim, Bedrock-edition Minecraft on 19132, the game ports of plenty of Source and Unreal titles. A UDP port usually shows Filtered or Closed here even while players connect to it just fine. For those games, trust the result on the TCP ports, the RCON port especially, and test the UDP game port the old way: by joining the game.

Timing the connection with TCP Ping

Once a port shows Open, TCP Ping answers the next question: how quickly and how reliably does it actually respond? Enter the Hostname or IP and Port, set Count: (10 by default) and start it. The app connects once a second, reports each individual time, then the minimum, average, maximum and whatever got lost along the way.

How TCP Ping reports loss
Probes sentAnsweredLoss shown
10100.0%
10910.0%
10820.0%

This is not a classic ping, worth saying plainly: it times how long opening a TCP connection to that port takes, which means it still works on servers that block ICMP outright. The number will not match in-game latency exactly, but a time that keeps climbing, or loss that keeps growing, is pointing at a real network problem either way.

Questions and answers

Can I check if a port is open on a remote server from my iPhone?
Yes. Enter the server's public address into Port Scanner and scan whichever ports matter to you. Switch to mobile data instead of home Wi-Fi if you want the view outside players actually get.
Why does my open UDP game port show Filtered?
Because the scanner tests TCP only. A UDP game port cannot be confirmed through this tool at all, joining the game is still the real test for those.
How many ports can I scan at once?
As many as you list or put into a range. The app probes up to 50 ports at once and gives each one up to 3 seconds to answer.
Is TCP Ping the same as ping?
No, it is not the same thing. It times a TCP connection to one specific port rather than sending ICMP echo packets, which is exactly why it keeps working on servers where ordinary ping is blocked.

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