# How to Sync to only localhost
**URL:** https://forum.syncthing.net/t/how-to-sync-to-only-localhost/24813
**Category:** Android
**Created:** [August 14, 2025, 8:04pm UTC](https://forum.syncthing.net/t/how-to-sync-to-only-localhost/24813 "2025-08-14T20:04:11Z")
**Posts on this page:** 6
**Page:** 1
### Author:  [@Cameronsplaze](https://forum.syncthing.net/u/Cameronsplaze)
#### Post date: [August 14, 2025, 8:04pm UTC](https://forum.syncthing.net/t/how-to-sync-to-only-localhost/24813/1 "2025-08-14T20:04:12Z")
Hi,
I’m trying to setup local-ONLY syncthing, for getting files in/out of android’s “private space”. (You can technically share files back and fourth, but not directories. I’d like to keep the directory structure without having to re-create it on both sides).
With syncthing files only on my device, I’d like to lock it down to local-host for both security and speed (make sure the files are only transferred on the device, and also don’t look for devices outside the phone to join).
The problem I’m hitting is for the two app/devices to see eachother, I need `Enable NAT Traversal` `Local Discovery` `Global Discovery` `Enable Relaying` checked (At least one of, I checked all of those together). I also need the device “link” set to `dynamic`. I tried setting it to `tcp://127.0.0.1`, but it fails to find the other device then. Is this kind of setup still possible? It worked on the `Syncthing` app, but I just switched to the `Synching-fork` version.
---
### Author:  [@tomasz86](https://forum.syncthing.net/u/tomasz86)
#### Post date: [August 14, 2025, 8:11pm UTC](https://forum.syncthing.net/t/how-to-sync-to-only-localhost/24813/2 "2025-08-14T20:11:03Z")
> [@Cameronsplaze](#):
>
> I tried setting it to `tcp://127.0.0.1` , but it fails to find the other device then.
I think you need to use different ports for the listen address, e.g. `tcp://localhost:22000` for the first, and `tcp://localhost:22001` for the second device, and then use these as their hardcoded addresses.
---
### Author:  [@Cameronsplaze](https://forum.syncthing.net/u/Cameronsplaze)
#### Post date: [August 14, 2025, 8:27pm UTC](https://forum.syncthing.net/t/how-to-sync-to-only-localhost/24813/3 "2025-08-14T20:27:37Z")
Thanks! But no luck. I tried both with/without the 4 options checked too.
That said, I only changed the listen address. Is there a setting somewhere I’m missing to make the other app _send_ on `:22001` maybe?
---
### Author:  [@tomasz86](https://forum.syncthing.net/u/tomasz86)
#### Post date: [August 14, 2025, 8:33pm UTC](https://forum.syncthing.net/t/how-to-sync-to-only-localhost/24813/4 "2025-08-14T20:33:09Z")
First, you need to change the listen address in each Syncthing instance in Actions → Settings, and then, on the opposite side, in the specific remote device settings, you need to put that address in the Advanced tab (instead of the default `dynamic`).
This is just an example, in your case it should say `localhost` or `127.0.0.1`.
---
### Author:  [@Cameronsplaze](https://forum.syncthing.net/u/Cameronsplaze)
#### Post date: [August 14, 2025, 8:47pm UTC](https://forum.syncthing.net/t/how-to-sync-to-only-localhost/24813/5 "2025-08-14T20:47:22Z")
Cool, the `Sync Protocol Listen Address` was exactly what I was missing. Thank you!
---
### Author:  [@system](https://forum.syncthing.net/u/system)
#### Post date: [September 13, 2025, 8:48pm UTC](https://forum.syncthing.net/t/how-to-sync-to-only-localhost/24813/6 "2025-09-13T20:48:08Z")
This topic was automatically closed 30 days after the last reply. New replies are no longer allowed.