Simple Voice Chat Offline Mode Warning: online-mode Fix

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Simple Voice Chat offline mode warning explained. Learn why online-mode=false triggers insecure voice chat warnings, what still works, and how to fix authentication issues.

Simple Voice Chat offline mode warning

Simple Voice Chat can work on offline-mode Minecraft servers, but it may show a warning that voice chat encryption is not secure. This usually happens when server.properties has online-mode=false.

Quick Answer

If you see:

Running in offline mode: Voice chat encryption is not secure!

It means the server is not using Microsoft account authentication. The mod prints this warning at startup whenever the dedicated server runs without authentication. Voice chat can still connect, but the encryption of the voice traffic is weaker than on an online-mode server.

What online-mode=false Means

In server.properties:

online-mode=false

This disables official account authentication. Some private servers use it for proxy setups, LAN-style access, or cracked launchers.

Simple Voice Chat encrypts voice packets with a key per player, and it hands that key to the player over the normal Minecraft connection. On an online-mode server that connection is encrypted. In offline mode it is not, so the key travels in the clear, and that is what the warning is about.

Does Simple Voice Chat Work in Offline Mode?

Yes, in many cases it works. The warning does not always mean voice chat is broken.

Offline mode does not change the networking. You still need:

  • Simple Voice Chat installed on server and client
  • Matching mod versions
  • A UDP port of its own for voice chat, not the Minecraft port. On a Space-Node server that is an extra allocation you create in the panel's Network tab, for free. Put its port in port= in the voice chat server config.
  • voice_host left empty. The official wiki says not to change it unless you know exactly why you need it.
  • A server restart after config edits

If voice chat does not connect at all, that is a port problem, not an offline-mode problem. The disconnected fix covers it.

When Offline Mode Breaks Voice Chat

Offline mode can cause problems when:

  • Players use mismatched usernames
  • A proxy changes UUID handling
  • The server and proxy disagree on online-mode
  • Client and server Simple Voice Chat versions differ

BungeeCord, Velocity and Proxy Setup

If you use a proxy, do not randomly set online-mode=false everywhere. A common secure setup is:

  • Proxy: online-mode=true
  • Backend servers: online-mode=false
  • Forwarding enabled and configured correctly
  • Simple Voice Chat proxy setup followed from the mod documentation

If player UUIDs change between the proxy and backend, voice chat may fail or authenticate incorrectly.

Should You Ignore the Warning?

For a private server with trusted friends, the warning may be acceptable.

For public servers, avoid offline mode unless you understand the risk. Online-mode=true is safer because it verifies player identity through Microsoft authentication.

Fix Checklist

  1. If possible, set online-mode=true
  2. Give voice chat its own UDP port (on Space-Node: an extra allocation in the Network tab) and set port= to it. Do not use port=-1, which the wiki warns may crash the server, and do not reuse Geyser's or the query's port
  3. Use matching Simple Voice Chat versions on client and server
  4. If using a proxy, configure forwarding correctly and follow the proxy setup in the Simple Voice Chat wiki
  5. Leave voice_host empty
  6. Restart proxy and backend servers
  7. Test with /voicechat test PlayerName in game (needs voicechat.admin)

If it still fails on a Space-Node server after these steps, ask in live chat.

Switching online-mode on an existing world

Be careful with step 1 on a world people already play on. Offline-mode servers store player data under UUIDs made from the player's name. Online-mode servers use the real account UUID. Switch modes and every player joins as a new player with an empty inventory, while the old data is still on disk under the old UUID. Our guide on moving a Minecraft server to a new host or region explains this in more detail. Make a backup first.

FAQ

Does Simple Voice Chat support offline mode? It can work, but it may show an insecure encryption warning.

Does the offline mode warning mean UDP is broken? No. UDP issues cause not connected or red plug icon. Offline mode warning is about authentication and security.

Can cracked servers use Simple Voice Chat? Technically some offline-mode servers can, but public cracked setups are less secure and may cause identity issues.

What should online-mode be for normal servers? true.

Does the offline mode warning mean I need to change voice_host? No. The warning is about authentication. Leave voice_host empty.

Related: Simple Voice Chat UDP 24454 fix, Simple Voice Chat disconnected fix