Support

System requirements

Item	Requirement
Android	Android 8.0 (API 26) or newer
Windows (optional)	Windows 10 or 11 — only needed for the PC features
Network	Both devices must be on the same Wi-Fi for PC, network player and NAS features
Cloud storage (optional)	OneDrive — needs a Microsoft account and an internet connection
USB DAC (optional)	A USB Audio Class 2.0 DAC and an Android device that supports OTG
Languages	12 languages (including Korean, English and Japanese)

Common problems

I want to connect my phone to my PC for the first time

The first connection must be made while the phone and the PC are on the same Wi-Fi. Listening away from home (remote connection) also needs this connection first.

Open the CastFi window on the PC. The connection request appears in this window.
On the phone, tap the device icon at the top right of CastFi and pick your PC from the list.
The phone asks you to check that the PC shows the same number and to allow it on the PC. The PC shows a new device connection request with a 6-digit confirmation code.
If both screens show the same number, click Allow on the PC. You are done when it says the device is connected.

If the numbers differ, or you did not start this connection, click Deny.

My PC does not appear in the list

Check that the phone and the PC are on the same Wi-Fi. A guest network, or a router that separates the 2.4 GHz and 5 GHz bands, can keep them from finding each other.
Make sure CastFi is running on the PC.
Check that Windows Firewall is not blocking CastFi's network access. In Windows Settings → Network & internet, also check that the current network is set to Private (a Public network blocks device discovery).
If your router has "AP isolation" or "wireless client isolation" enabled, devices cannot talk to each other.
If a VPN is on, on the phone or the PC, turn it off and try again.
If it still does not work, send a report from CastFi on your phone. We will look at the connection log to find the cause.

My USB DAC is not detected

Reconnect the OTG cable and the DAC, then choose Allow when Android asks for permission to access the USB device.
Some DACs need their own power supply or a powered hub.
If another music app has already claimed the DAC, close that app and try again.
Supported formats differ by model — check what the app reports once the DAC is connected.

Playback stops when the screen turns off

Go to system settings → Apps → CastFi → Battery and set it to Unrestricted.
Some manufacturers close background apps aggressively; locking CastFi in the recent-apps list helps.

Tracks from other music apps do not show up

Android's notification access permission is required. Open the settings from the prompt inside the app and enable CastFi. Without it, CastFi's own playback and every other feature still work normally.

I want to change which folders are scanned

You can add or remove music folders in settings. Removing a folder takes its tracks out of the library only — the actual files on your device are not deleted.

I want to listen to music in my OneDrive

Go to settings → Music folders · network · cloud → Add cloud storage, sign in with your Microsoft account and pick a music folder.
If the app says your sign-in has expired, sign in again on the same screen. The folders you added stay as they are.
Whether to stream or download over mobile data is set in settings → Mobile data.
Removing the account leaves your downloaded songs and the original files in OneDrive untouched. You can revoke CastFi’s access on your Microsoft account page (account.live.com/consent/Manage).

I want to turn off statistics and crash reports

Both usage statistics and automatic crash reports have their own switches in settings. Everything that is collected is described in the privacy policy.

CastFi for Windows

The desktop app can be downloaded here.

Download the latest version (v0.10.8) →

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