The “No Connected Devices” error in AltStore is a communication failure where the AltServer desktop client cannot establish a recognized “handshake” with the iOS device due to specific driver conflicts, software restrictions, or network isolation issues. When this error appears, it halts the installation or refreshing of apps like Delta or YouTube++, effectively rendering the sideloading process useless until the connection path is restored. This issue is most prevalent during the initial setup but can occur spontaneously if software updates alter the required drivers.
For Windows users, the primary culprit is almost always the version of iTunes and iCloud installed on the PC; specifically, the Microsoft Store versions lack the essential “Apple Mobile Device Support” drivers required for AltStore to function. Correcting this involves a strict process of uninstalling the Store versions and replacing them with the direct download executable files provided by Apple. Without these specific legacy drivers, AltServer is invisible to the connected iPhone or iPad.
On macOS, the root cause is fundamentally different, typically stemming from the system’s Mail application plugin architecture. Unlike Windows, the Mac ecosystem relies on a specific “AltPlugin.mailbundle” running inside the native Mail app to authenticate the connection with Apple’s developer servers. If this plugin is disabled, outdated, or blocked by macOS security settings, AltServer cannot verify the device’s identity, resulting in the “No Connected Devices” prompt.
Beyond these platform-specific software conflicts, broader network and hardware variables such as firewall settings, “Trust” permissions, and physical cable integrity play a significant role. Transitioning from identifying the error to solving it requires a systematic approach, starting with the most common software environment issues and narrowing down to specific network configurations.
What Causes AltStore to Show the “No Connected Devices” Error?
The “No Connected Devices” error is a technical breakdown in the communication protocol where the AltServer application on your computer fails to detect and authenticate the unique device identifier (UDID) of your iPhone or iPad via the established local connection.
To understand better why this specific error occurs, we must look at the underlying mechanics of how AltStore interacts with Apple’s restrictive ecosystem. The “Handshake” is a metaphor for the cryptographic pairing process that must occur between an iOS device and a trusted computer. When you plug your phone in, or attempt to connect via Wi-Fi, the computer doesn’t just need to “see” the storage; it needs permission to execute developer commands on the device. AltStore relies entirely on the background frameworks provided by iTunes (on Windows) or Finder (on Mac) to send these commands.
The Root Attributes of this error almost always point to a missing link in this chain. It is rarely a bug within the AltStore app itself, but rather an environmental issue on the host computer. For the handshake to succeed, the “Apple Mobile Device Support” service must be running, the device must be “Trusted,” and the network ports must be open. If any single variable—such as a firewall blocking port communication or a driver version that doesn’t support the current iOS version—is out of alignment, AltServer returns the null value of “No Connected Devices.”
Key reasons for this failure differ slightly by platform but generally fall into three categories:
1. Driver Absence: The computer lacks the specific `.dll` or system files to recognize the iPhone as a developer target.
2. Permission Denial: The phone has not unlocked its data port to the computer (The “Trust” prompt).
3. Software Mismatch: The version of AltServer is too old for the iOS version, or the iTunes version is incompatible.
How to Fix “No Connected Devices” on Windows: Is Your iTunes Correct?
Fixing this error on Windows requires addressing three main components: uninstalling Microsoft Store versions of Apple software, installing the direct download versions (non-store), and verifying device recognition within iTunes itself.
Specifically, the vast majority of connection failures on PC stem from how Apple packages its drivers in different distribution channels. Microsoft mandates that apps on the Microsoft Store be sandboxed, meaning they cannot install deep system-level drivers in the same way a standard installer can. Unfortunately, AltServer requires these deep system drivers—specifically `AppleMobileDeviceSupport64.msi` and `AppleApplicationSupport64.msi`—to communicate with your phone. If you installed iTunes or iCloud from the Microsoft Store, you have a cosmetic version of the software that works for music but fails for developer tasks.
To start the remediation process, you must completely uninstall iTunes and iCloud from your computer. Go to “Add or Remove Programs” in Windows Settings and ensure every trace of Apple software is removed. Once the system is clean, you must download the “Direct Download” versions. These are often hidden on Apple’s website, as they push users toward the Store. Once the correct versions are installed (detailed below), you must launch iTunes and plug in your phone. If iTunes shows a small phone icon in the top toolbar, the drivers are working. Only after iTunes confirms the connection should you launch AltServer. If iTunes cannot see the phone, AltServer never will.
Which Version of iTunes and iCloud Should You Download?
The direct download (.exe) versions of iTunes and iCloud are superior because they include the “Apple Mobile Device Support” and “Apple Application Support” modules, whereas the Microsoft Store versions lack these critical background drivers needed for AltServer.
Specifically, you must avoid the “Get it from Microsoft” buttons at all costs. The Microsoft Store versions are streamlined for consumer use—listening to music or syncing photos—but they are stripped of the background services that allow third-party applications like AltStore to inject code into the iOS device. This distinction is the single most common reason for the “No Connected Devices” error on Windows 10 and 11.
To illustrate, when you run the `.exe` installer (often labeled as “Windows 10 (64-bit)” on the Apple site, but not the Store link), you will see a progress bar installing “Apple Mobile Device Support.” This specific component is the bridge AltServer walks across to reach your phone. Furthermore, you also need the non-Store version of iCloud. AltServer uses the iCloud interface to authenticate your Apple ID during the signing process. If you have the Store version of iCloud, AltStore cannot retrieve the necessary data to sign the apps.
- Key Action: Download the “iTunes for Windows (64-bit)” installer directly from Apple’s Knowledge Base or the AltStore FAQ page links.
- Key Action: Download “iCloud for Windows” (Look for the link that says “download iCloud for Windows 7 and 8” – even if you are on Windows 10/11, this is the version containing the necessary independent drivers).
Is the “Trust This Computer” Prompt Accepted?
Yes, accepting the “Trust This Computer” prompt on your unlocked iPhone is a mandatory security requirement for AltServer to read the device’s UDID and inject applications.
More specifically, this physical security layer is a gatekeeper that prevents unauthorized chargers or computers from stealing data or installing malware on your device. When you plug your iPhone into a computer for the first time, or after resetting your network settings, iOS will display a pop-up dialog asking, “Trust This Computer?”.
If you ignore this prompt, click “Don’t Trust,” or if your phone is locked when you plug it in, the USB connection defaults to “Charging Only” or “Camera Mode.” In these modes, the data channel is restricted, and the device does not broadcast its identity to iTunes or AltServer. You must unlock the device screen, plug in the cable, wait for the prompt, tap Trust, and then enter your device passcode to confirm. Only then is the encrypted channel established, allowing AltServer to “see” the connected device.
How to Fix “No Connected Devices” on macOS: Is the Mail Plug-in Active?
The solution for macOS users revolves around the Mail app, specifically requiring you to install, enable, and apply the “AltPlugin.mailbundle” to authorize the signing process with Apple’s servers.
Unlike Windows, which relies on iTunes drivers, the Mac ecosystem integrates this functionality directly into the system via the native Mail application. This often confuses users who do not understand why an email client is involved in sideloading apps. The technical reason is that the Mail app possesses specific system “entitlements” that allow it to communicate securely with Apple ID servers. AltStore piggybacks on this existing secure connection to sign your apps without triggering Apple’s security alarms. If this plug-in is not active, AltServer has no method to authenticate, resulting in the “No Connected Devices” or “Could not connect to Mail plug-in” error.
The process to fix this is manual and requires specific steps inside the Mail app:
1. Launch Mail: Open the native Mail app on your Mac (even if you don’t use it for email).
2. Access Preferences: Click “Mail” in the top menu bar, then select “Settings” or “Preferences” (depending on your macOS version).
3. Manage Plug-ins: Navigate to the “General” tab and look for a button labeled “Manage Plug-ins…” at the bottom.
4. Enable AltPlugin: You will see “AltPlugin.mailbundle” in the list. Check the box next to it.
5. Restart: Click “Apply and Restart Mail.”
It is critical to note that the Mail app must remain running in the background whenever you are trying to install or refresh apps via AltServer. If you close the Mail app, the connection is severed, and AltServer will lose sight of the device.
How to Enable Wi-Fi Sync for Wireless Refreshing?
Enabling Wi-Fi sync involves configuring settings in iTunes (Windows) or Finder (macOS) to allow data transfer over the local network, provided both devices share the exact same Wi-Fi frequency and subnet.
Afterwards, once you have successfully established a wired connection and fixed the initial drivers, you likely want to enable wireless refreshing so you don’t have to plug your phone in every seven days. The “No Connected Devices” error frequently appears for users trying to refresh wirelessly because the computer stops “looking” for the phone once the USB cable is unplugged. To fix this, you must explicitly tell the Apple ecosystem to keep the data channel open over Wi-Fi.
The Fix requires you to connect your device via cable one last time.
- On Windows: Open iTunes, click the Device icon, go to the Summary tab, and under “Options,” check the box that says “Sync with this iPhone over Wi-Fi.” Click Apply.
- On macOS: Open Finder, select your iPhone from the sidebar, and under the General tab, check “Show this iPhone when on Wi-Fi.” Click Apply.
Condition: For this to work, your computer and your iPhone must be on the same local network. A common issue arises with dual-band routers. If your PC is on Ethernet or 5GHz Wi-Fi, and your iPhone is on the 2.4GHz band of the same router, they might be isolated from each other depending on your router’s “AP Isolation” settings. Ensure both are on the exact same SSID and frequency to guarantee AltServer can find the device wirelessly.
Are Firewalls or Antivirus Software Blocking AltServer?
Yes, third-party antivirus software and the native Windows Defender Firewall frequently interpret AltServer’s network discovery attempts as potential threats, thereby blocking the connection port.
To start troubleshooting network interference, you must acknowledge that AltServer behaves like a server—it listens for incoming connections and broadcasts its presence on the local network. Security software often flags this behavior as suspicious. If you have verified your drivers and cable are working but still see “No Connected Devices,” your firewall is likely silently dropping the data packets.
Diagnosis involves checking your active network profile. On Windows, if your network is set to “Public,” Windows effectively puts up a shield that hides your computer from other devices (like your iPhone) on the network. You must ensure your Wi-Fi or Ethernet connection is set to “Private” in Windows Settings > Network & Internet. Furthermore, you should create an exclusion for `AltServer.exe` in your firewall settings.
1. Open “Windows Defender Firewall with Advanced Security.”
2. Check “Inbound Rules.”
3. Ensure AltServer is listed and has a green checkmark (Allowed).
4. If not, create a “New Rule” -> Program -> Select the AltServer executable -> “Allow the connection.”
Is the Bonjour Service Running Correctly?
The Bonjour service is absolutely essential for device discovery, and if it is stopped or disabled in the background, AltServer will fail to locate any iOS devices on the network.
Specifically, Bonjour is Apple’s zero-configuration networking protocol that enables devices to find each other without manual IP address entry. If you installed iTunes correctly but disabled startup items to speed up your PC, you might have accidentally killed Bonjour. Without it, your computer is essentially blind to Apple devices on the Local Area Network (LAN).
To illustrate, you can verify this status using the Windows Task Manager.
- Press `Ctrl + Shift + Esc` to open Task Manager.
- Click the “Services” tab.
- Scroll down and look for a service named `Bonjour Service` or `Dnscache`.
- The status should be “Running.”
- If it says “Stopped,” right-click it and select “Start.”
- If the service is missing entirely, it indicates a corrupted iTunes installation, and you must reinstall the package to restore the Bonjour protocol.
How to Troubleshoot Physical Connection Issues?
Troubleshooting physical hardware involves verifying the integrity of the lightning/USB-C cable to ensure data transfer capabilities and testing different USB ports to rule out power or driver failures at the hardware interface level.
Next, before assuming complex software failures, it is prudent to rule out the simplest mechanical variables that often go overlooked. Not all cables are created equal. The market is flooded with cheap, third-party cables sold at gas stations or convenience stores that are wired for “Charge Only.” These cables lack the internal data pins required to transmit information between the PC and the iPhone. If your phone charges but does not appear in iTunes or AltStore, you are likely using a charge-only cable. Always use the official Apple OEM cable or an MFi-certified (Made for iPhone) cable to ensure data throughput.
Additionally, the USB port on your computer can be the point of failure.
- USB 3.0 vs. 2.0: Sometimes, older motherboard drivers for USB 3.0 ports can conflict with Apple’s mobile device drivers. If you are having trouble, try plugging the cable into a slower USB 2.0 port (usually black, not blue) to see if detection improves.
- Port Debris: Inspect your iPhone’s charging port. Compacted pocket lint can prevent the cable from seating fully, allowing power to flow (charging) but preventing the precise contact needed for data transfer. Use a non-conductive pick to gently clean the port.
AltStore vs. Sideloadly: Which Has Better Device Detection?
Sideloadly generally offers superior device detection reliability because it employs a direct injection method that is less dependent on the unstable Wi-Fi Sync protocol required by AltServer.
Moreover, comparing the technical infrastructure of both tools reveals why switching to Sideloadly is often a viable solution when AltStore fails to recognize a device due to driver corruption or network restrictions.
Can You Install IPAs Without a Computer to Avoid This Error?
Yes, it is entirely possible to install IPA files without a computer, thereby completely bypassing the “No Connected Devices” error since there is no local server to connect to. This method relies on Over-The-Air (OTA) installation services or signing services that utilize an enterprise certificate rather than your personal Apple ID. When you use a “No-PC” method, the authentication happens between your device and a third-party server, eliminating the need for AltServer to detect your phone via USB or Wi-Fi. However, this convenience comes with significant stability trade-offs regarding how long the app remains functional.
To understand if this method suits your needs, consider the following technical distinctions:
- Enterprise Certificates: Services like iOSGods App or Scarlet use shared certificates. While this solves the connectivity issue, these certificates are frequently subjected to Certificate Revocation by Apple, causing apps to crash unexpectedly.
- Zero Infrastructure: Unlike AltStore, which requires a daemon running on a local PC, OTA methods work strictly through the Safari browser, making them immune to firewall or driver issues.
- Paid Signing Services: For a more permanent fix without a PC, users often opt for paid services (like Signulous) which register the device’s UDID, offering a full year of uptime without weekly refreshes or connection errors.
Why Does AltStore Lose Connection After 7 Days?
It is a common misconception that AltStore loses connection because 7 days have passed; in reality, the 7-day limit is an Apple-imposed rule, and the connection error merely prevents the necessary renewal. Apple restricts free developer accounts to a 7-day lifespan for any Provisioning Profile tied to an App ID. Consequently, apps sideloaded via AltStore must “check in” with the AltServer on your computer to re-sign the certificate before this period expires. If the “No Connected Devices” error is present during this critical window, the refresh fails, and the app ceases to open.
Here is the breakdown of the relationship between the connection and the expiration:
- The Apple Rule: The 7-day expiration is not a bug but a security feature for non-paid developer accounts; the app is programmed to stop working if the Digital Signature is not renewed.
- The Connection Role: AltStore attempts to perform a Background Refresh via Wi-Fi Sync. If the device cannot be detected due to network isolation or Bonjour service failures, the new signature cannot be applied.
- Validation Failure: When you see “App is no longer available” after a week, it confirms that while the device might have been connected physically, the software bridge (AltServer) failed to handshake with the device to reset the timer.
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