AltServer Could Not Find This Device

AltServer could not find this device usually means your iPhone or iPad is not visible over USB or Wi-Fi because of trust, driver, or network issues.

What AltServer Could Not Find This Device Error Means

AltServer sits on your Windows PC or Mac and talks to AltStore on your iPhone or iPad. When everything works, AltServer signs apps with your Apple ID and pushes them to your device over USB or Wi-Fi. The message “AltServer could not find this device” appears when that link breaks and your computer can’t see your phone or tablet in a way AltServer understands.

This problem can show up while you install AltStore for the first time, refresh an app, or enable JIT for an emulator. In each case, AltServer expects a live connection to your iOS device. If that connection fails, you see AltServer could not find this device and the action stops halfway.

Common triggers fall into a few broad buckets. A USB cable that only charges but doesn’t pass data, a locked device that never shows the Trust prompt, or drivers that never installed correctly on Windows. On both platforms, AltServer may also lose track of your phone if the computer and device sit on different Wi-Fi networks or if a firewall blocks local traffic.

The good news is that this error rarely points to a broken phone. In most cases, you bring AltServer back to life by walking through a short list of connection checks, then updating a few settings on Windows or macOS. The sections below walk through those steps in a clear order so you can get AltStore and your apps running again.

Quick Checks Before Deeper Fixes

Before you change drivers or reinstall software, it helps to run through a few quick checks. These fixes are fast, low risk, and often clear the AltServer could not find this device message without any deeper digging.

Restart AltServer And AltStore — Quit AltServer from the system tray or menu bar, force-close AltStore on your device, then launch AltServer again and reopen AltStore.
Unlock Your Device And Keep It Awake — Wake your iPhone or iPad, enter the passcode, and leave the screen on while you refresh apps or install AltStore.
Check The Cable And USB Port — Use a short, known-good data cable, plug it directly into the computer, and avoid hubs or front-panel ports if possible.
Confirm Trust Prompts In Finder Or iTunes — Connect your device, open Finder on macOS or iTunes on Windows, and accept any “Trust This Computer” prompts on both sides.
Move To The Same Wi-Fi Network — Make sure the computer and iOS device share the same router and band, and avoid guest or “isolated” networks.
Turn Off VPN And Security Apps Temporarily — Pause VPN clients or aggressive security tools that might block local discovery between AltServer and your device.

If the error still appears after these steps, you’re likely dealing with a driver, service, or network configuration issue. The next sections split fixes by platform and network so you can target the right area instead of changing everything at once.

AltServer Could Not Find This Device On Windows

On Windows, the device not found issue usually ties back to Apple services, drivers, or firewall settings. AltServer leans on iTunes and iCloud components to talk to your phone, so if those pieces come from the wrong source or stop running, your device disappears from AltServer’s view.

Clean Up iTunes And iCloud Installations

AltStore’s own guide recommends using the Apple website builds of iTunes and iCloud instead of the Microsoft Store versions. The Store builds install different components, and that can block AltServer from reaching your phone over USB or Wi-Fi.

Uninstall Store Versions — Open Apps & Features, remove iTunes and iCloud that came from the Microsoft Store, and restart Windows.
Install From Apple’s Site — Download iTunes and iCloud directly from Apple, install both, then reboot once more so all services start correctly.

Restart Apple Mobile Device Service

Even with the right iTunes build, the Apple Mobile Device Service can stop working. When that happens, Windows no longer exposes the iPhone connection in the way AltServer expects.

Open The Services Panel — Press the Windows key, type “services.msc”, and press Enter.
Find Apple Mobile Device Service — Scroll to the entry, right-click it, and choose Restart so the driver stack reloads.
Set Startup Type To Automatic — In Properties, choose Automatic so this service always starts with Windows.

Allow AltServer Through Windows Firewall

Even if AltServer works over USB, a strict firewall can block Wi-Fi refresh and trigger the error the moment you unplug the cable.

Open Firewall Settings — In Control Panel, go to Windows Defender Firewall and select Allow an app through firewall.
Enable AltServer Entries — Find any AltServer entries in the list and allow them on both private and public networks.
Test With Cable And Wi-Fi — Plug in your device, refresh once over USB, then unplug and test a Wi-Fi refresh while both devices share the same network.

Refresh Device Drivers Through iTunes

If Windows doesn’t recognize your iPhone at a low level, AltServer has no chance. iTunes is still the easiest way to repair those drivers.

Connect The Device And Open iTunes — Wait until your iPhone or iPad icon appears in the iTunes toolbar.
Accept Any Trust Messages — Tap Trust on your device, confirm on the computer, then close and reopen AltServer.
Replug If Needed — Unplug the cable, count to five, plug it back, and check that iTunes still sees the device before you try another AltStore action.

Fixing Device Not Found On Mac

On macOS, the AltServer could not find this device message usually points to a missing trust relationship, a Finder issue, or a Wi-Fi setting. The fixes here rely on built-in tools, so you don’t need extra utilities.

Verify Trust And Finder Visibility

AltServer depends on the same underlying link that Finder uses. If Finder can’t see your phone, AltServer will fail in the same way.

Open Finder And Check Locations — Plug in the device and look under Locations in the Finder sidebar for your iPhone or iPad.
Tap Trust On The Device — When the trust dialog appears on your iOS screen, choose Trust and enter your passcode.
Reopen AltServer — Quit AltServer from the menu bar, wait a moment, then launch it again and try installing or refreshing from AltStore.

Enable Connect Over Wi-Fi In Finder

For Wi-Fi refresh, your Mac needs permission to see the device without a cable. That setting lives inside the device summary in Finder.

Open The Device Summary — In Finder, click your iPhone under Locations, then stay on the General tab.
Turn On Show This iPhone When On Wi-Fi — Check the box so the Mac keeps a wireless pairing with your device.
Apply And Reconnect — Click Apply, eject the device, unplug the cable, and wait a minute for the Wi-Fi link to settle before you refresh apps.

Check VPN, Firewall, And Mail Plug-In

On some Macs, a VPN client or local firewall filter stops AltServer from talking to your device. The AltStore team also uses a Mail plug-in on macOS, so that part must be enabled for certain actions.

Pause VPN And Local Firewalls — Temporarily disable VPN apps or third-party firewalls, then test AltStore again.
Open Mail And Enable The Plug-In — In the Mail app, open Preferences, check the AltServer plug-in entry, and restart Mail so the plug-in loads.
Retry With USB Attached — Keep the device plugged in while you refresh once; then test Wi-Fi after you see a successful run.

Wifi And Network Fixes For AltServer

Even when USB works, AltServer might lose your device as soon as you unplug the cable. That usually points to a network setup where devices can’t see each other, even though both appear online.

Use the table below to match what you see with a likely cause and a quick fix.

Network Issue	Symptom	Quick Fix
Different Wi-Fi Networks	AltServer works over USB but fails the moment you unplug.	Connect the computer and device to the same SSID and band, then retry.
Guest Or Public Network	AltStore refresh fails everywhere on campus, office, or café Wi-Fi.	Use your phone’s hotspot or a home router where local devices can talk.
Router Client Isolation	The router lets both devices browse the web but they never see each other.	Disable client isolation on the router or move both devices to another network.
Firewall Blocking Local Ports	AltServer appears in the tray, yet AltStore can’t reach it over Wi-Fi.	Allow AltServer through the system firewall and any security suites, then restart.

If none of these changes help, stick with USB for now. AltStore will still install and refresh apps as long as AltServer can see your device over the cable, even if Wi-Fi remains unreliable on a school or work network.

Advanced Fixes And Clean Reinstall Steps

Once you’ve checked cables, trust prompts, Apple services, and Wi-Fi, a small number of stubborn setups still trigger the same error. At that point, a clean sweep of AltServer and AltStore often clears old data or mismatched versions that stand in the way.

Update Or Reinstall AltServer And AltStore

Old builds of AltServer or AltStore can misbehave with current iOS or macOS versions. A fresh install makes sure both ends speak the same protocol and use current fixes from the developer.

Download The Latest Release — Grab the newest AltServer installer from the official site for Windows or macOS.
Remove Old AltStore From The Device — Delete AltStore from your iPhone or iPad Home Screen to clear any broken link.
Reinstall With USB Connected — Run the new AltServer build, plug in the device, and install AltStore again while the cable stays attached.

Reset Pairing And Check Date/Time

Strange pairing glitches can also block the link between AltServer and your phone. Date and time drift can interfere with Apple’s security checks as well.

Reset Location & Privacy On iOS — In Settings > General > Transfer or Reset > Reset, choose Reset Location & Privacy so trust prompts appear again.
Trust The Computer Again — Plug in the cable, accept the new trust prompts on both Mac or PC and the device, then reopen AltServer.
Set Automatic Date And Time — Turn on automatic time on both the computer and iOS device so certificate checks pass cleanly.

Try A Different USB Port, Cable, Or Computer

At this stage, it’s worth ruling out hardware. A marginal port or cable might work just enough for charging while failing during longer operations like app refresh.

Test Another Cable — Use a short MFi-certified cable, preferably the one that came with your device.
Switch USB Ports — Move from front ports to rear motherboard ports on a desktop, or avoid hubs and docks on a laptop.
Borrow Another Computer — Install AltServer on a second machine and see whether the device connects cleanly there.

When AltServer Still Cannot Find Your Device

If you still see AltServer could not find this device after working through Windows fixes, Mac steps, network changes, and a clean reinstall, you’re dealing with a rare edge case. At that point, it helps to capture as much detail as you can, then reach out to the AltStore community or the official support channels.

Note your platform, AltServer version, iOS version, how the device connects, and which steps you tried. Screenshots of the exact error and any console logs from AltServer also help. With that information in hand, you give the developer and other users enough context to point out a small setting or pattern that fits your setup.

In day-to-day use, though, this error usually comes down to one of the basics: a cable issue, a trust prompt that never appeared, Apple services that stopped, or a network where devices can’t see each other. Once those pieces line up, AltServer and AltStore tend to run quietly in the background again, keeping your sideloaded apps refreshed without complaint.