Clash First-Time Installation Checklist: Cross-Platform Setup Steps and Common Mistakes

When setting up Clash for the first time, there are only a few things that really need confirmation: the client matches the system architecture, the configuration loads correctly, a policy group has been selected, and the proxy entry point is enabled. Most problems come from the order of operations. For example, enabling the system proxy before updating the subscription, or changing DNS, rules, and TUN before verifying the basic connection, makes it difficult to identify the source of an issue.

Clash is a common name for a family of rule-based proxy cores and their client ecosystem. Desktop and mobile clients may use different labels, and the underlying core may be Clash Meta (now commonly known as mihomo), but the initialization process is largely the same. This checklist does not depend on a particular interface and works for compatible clients commonly used on Windows, macOS, Android, iOS, and Linux.

1. Confirm the client, system, and configuration source before installing

Before downloading, confirm the device platform and processor architecture. Windows systems are commonly x64, while some newer devices use ARM64. On macOS, distinguish between Apple silicon and Intel. On Linux, check not only the architecture but also the package format and desktop-environment support. An architecture mismatch may prevent the program from starting, or it may run through a compatibility layer with issues affecting service installation, tray behavior, or performance.

Pre-installation checklist

Check the operating system version: Review the client's release notes for minimum system requirements. Older systems may lack required runtime components or system APIs.
Check the processor architecture: Do not rely on the device brand alone. Open the system information page and look for labels such as x64, ARM64, Apple Silicon, or another architecture.
Keep the subscription details handy: Prepare the subscription URL, configuration file, or import method provided by the service. Subscription URLs often contain access credentials and should not be shared in public chats, screenshots, or logs.
Record the current network settings: If the system already has a manual proxy, VPN, network filter, or enterprise security tool configured, note its state first so you can restore settings one by one if connectivity problems occur.
Avoid running similar tools at the same time: Multiple programs competing for the system proxy, virtual network adapter, DNS, or local ports can make the first test results unreliable.

If another proxy client was previously installed on the device, quitting the program does not necessarily restore the proxy settings. Windows and macOS may retain a manual proxy address, while mobile operating systems may still show a VPN configuration. Before installing a Clash client, check the system network settings and make sure no leftover proxy port points to a program that is no longer running.

2. Install by platform and grant only the necessary permissions

Opening the client only confirms that its graphical interface has started; it does not mean system traffic is being handled by the proxy core. On the first launch, check the core status, configuration directory, and permission prompts before deciding whether to install a system service or enable a virtual network adapter. Administrator access is not required for every operation, but service mode, TUN drivers, and some system-level settings usually need additional authorization.

Windows: Confirm the core starts before enabling service mode

After installing on Windows, launch the client normally and check whether the core is running and the local proxy port is listening. If the client offers “service mode,” “administrator service,” or a similar feature, it is generally used to let a standard-user interface manage TUN, routes, or system settings. You do not necessarily need to install the service for the first system-proxy test. Wait until basic proxy access works, then follow the client's instructions to install it; this makes troubleshooting easier.

If the installer is blocked by a system security warning, verify the download source and publisher information rather than disabling system protection. Company- or school-managed devices may restrict drivers, services, and proxy changes; those permissions should be handled by the device administrator.

macOS: Pay attention to chip architecture and network-extension permissions

On macOS, choose the build that matches your chip. The first launch may require confirmation of the app's source. Enabling TUN or an enhanced mode may also prompt for an administrator password, network-extension approval, or VPN configuration permission. If a feature does not take effect immediately after authorization, fully quit and reopen the client, then check the VPN and filter entries in System Settings.

Do not migrate every rule, script, and override from an old client during the first launch. Import the original subscription and complete a connectivity test first. This helps distinguish a system-permission problem from incompatibility between the old configuration and the new core.

Android and iOS: Understand system VPN authorization

Mobile clients usually take over traffic through the system VPN interface. The first time you tap Connect, the system displays a VPN permission prompt; only after you approve it do the VPN icon in the status bar and the client's connection status become meaningful. Android battery optimization may stop the client in the background. If the connection drops after the screen has been locked for a while, adjust the background activity settings for that client. Menu names vary by manufacturer, so do not change every battery-saving option during initial setup; first confirm that background interruption is actually occurring.

iOS clients must use the network-extension mechanism provided by the system. If the subscription imports successfully but the VPN cannot be established, check whether a broken VPN configuration already exists or whether device-management policies prohibit adding a new one.

Linux: Check execution permissions, desktop sessions, and proxy scope

Linux clients may be distributed as distribution packages, archives, or AppImages. After installation, distinguish between “the program starts” and “the desktop environment is using the proxy settings.” Desktop environments differ in their support for system proxies, and command-line programs may not read desktop proxy settings. For the first test, use the client's built-in connection page or a browser known to support system proxies. Do not conclude that the entire client is broken based only on the result of one terminal command.

3. Import the subscription and confirm that the configuration actually loads

A subscription is a remote configuration entry point that typically contains proxy nodes, policy groups, and rules. After pasting the URL into the client, you still need to download or update it and set the downloaded result as the active configuration. Saving the subscription URL without activating its configuration is one of the most common omissions after a fresh install.

Four checks after importing a subscription

Update time: Confirm that the subscription was updated successfully just now, rather than remaining blank or showing an old cache.
Configuration status: Confirm that the configuration associated with the subscription is selected, and that the core log shows no YAML parsing errors, invalid fields, or failed rule-provider downloads.
Policy group contents: Open the proxy or policy page and check that commonly used policy groups contain selectable nodes rather than being empty.
Update behavior: Check whether the client supports scheduled updates and set a reasonable interval for your needs. Refreshing too often will not improve node quality and may trigger server-side limits.

Some services generate different configuration formats based on the client's request. If a subscription opens in a browser but the client reports an unsupported format, the response may be a plain node list, a format for another app, or a login page rather than Clash-compatible YAML. In that case, return to the provider's setup page and select the appropriate subscription type; do not simply rename the file extension to YAML.

mixed-port: 7890
mode: rule
allow-lan: false
log-level: info

The snippet above is only meant to explain a few basic fields: mixed-port is the local mixed proxy port, mode: rule means traffic is handled according to rules, and allow-lan: false means the proxy is not exposed to LAN devices by default. Real subscriptions usually contain much more, including proxies, policy groups, DNS settings, and rules. Do not treat this snippet as a complete configuration to run directly.

4. Complete the first connectivity test with as few variables as possible

Once the configuration loads successfully, do not enable every advanced feature immediately. The goal of the first connection is to prove that application traffic can enter the local proxy port and be routed to an available exit according to the configuration. The most reliable approach is to use rule mode, select a specific policy node, enable the system proxy, then visit several stable sites while watching the logs.

Recommended verification steps

Set the operating mode to rule mode. This checks rule matching without forcing every request through one policy as global mode does.
Manually select a healthy node in the main policy group. A successful latency test only means that the probe received a response; it does not mean every destination will be reachable.
Enable the system proxy and leave TUN disabled for now. Browsers usually read the system proxy, making them suitable for the first round of testing.
Open a regular website, then visit a destination that requires proxy handling. Check whether the client's connection list shows the domain, destination address, matched rule, and policy name.
If access fails, first disable the system proxy to restore the network, then check the log for timeouts, connection refusals, DNS failures, or configuration errors.

The info log level is usually sufficient. Connection records in the log show that application traffic has entered Clash. If the browser reports an error but the connection list shows no new requests, first check whether the system proxy is enabled, whether the browser uses its own proxy settings, and whether the local port matches the configuration. If connection records appear but repeatedly time out, focus instead on the node, policy selection, remote network, and rule destination.

In rule mode, each request is matched from the top of the rule list downward and passed to the specified policy after the first match. The configuration usually ends with a fallback rule for traffic that matched nothing earlier. There is no need to change the rule order during the first test. Once the original subscription works, add domain or process rules based on actual needs.

5. Enable TUN and DNS only after basic proxying works

The system proxy mainly affects applications that follow the operating system's proxy settings. Some games, command-line tools, background services, and programs using specialized network stacks may bypass it. TUN mode uses a virtual network interface and routing to handle a broader range of traffic, but it also depends more heavily on system permissions, drivers, routing tables, and DNS configuration.

Before enabling TUN, record the working state under the system proxy. Then disable the system proxy or switch using the method recommended by the client, so you can identify the traffic entry point during troubleshooting. Some clients allow the system proxy and TUN to run together, but for an initial setup it is best to use only one primary traffic-capture method. After enabling TUN, retest the browser, then test apps that previously bypassed the proxy, and watch the connection list for their requests.

What to check when TUN fails to start

Whether the client has administrator, VPN, or network-extension permission.
Whether another VPN, virtual network adapter, or network-filtering tool is modifying routes at the same time.
Whether the TUN device was created successfully and whether the core log reports a route or interface error.
Whether the default network adapter changed after switching networks, such as moving from Ethernet to Wi-Fi.
Whether LAN, printer, or development-environment subnets need direct-connection rules.

DNS is a key suspect when you are connected but domains will not open. If domain access fails while direct access to a known service still responds, the DNS path usually needs attention. Clash or mihomo configurations may enable built-in DNS and use enhanced modes such as fake-ip or redir-host. Their compatibility and appropriate use cases differ, so do not switch between them casually without understanding the original configuration design.

When troubleshooting DNS, first determine whether the request reaches the core. Then check whether the upstream DNS server is reachable, whether rules send DNS requests through the wrong exit, and whether the system or browser has its own encrypted DNS enabled. A browser's secure DNS can bypass the system resolver, so the same domain may produce different results in the browser and other applications.

6. Common mistakes during initial setup

Mistake 1: Assuming lower latency always means faster access

A latency test reflects only the response from a specific probe target at a specific time. Real-world speed also depends on line bandwidth, congestion, the destination site, the transport protocol, and the local network. When choosing a node, consider connection stability and actual access results rather than repeatedly refreshing the latency number.

Mistake 2: Assuming no policy selection is needed after importing a subscription

A subscription may set the main policy group to automatic selection by default, or it may remain on an unavailable node. After importing it, open the policy group and check the current selection. If the configuration uses nested policy groups, also confirm which node or automatic testing group the top-level group ultimately points to.

Mistake 3: Assuming an illuminated connection button means traffic is being proxied

A running status usually only means that the core or VPN session has started. The system proxy may still be disabled, or TUN routing may have failed to initialize. Check the system status, connection list, and actual access results instead of relying on a single switch.

Mistake 4: Changing the core, DNS, and rules all at once

Changing several variables at once destroys your troubleshooting baseline. Return to the original subscription, disable custom overrides and TUN, and test only the system proxy. Once the basic path is confirmed, restore DNS overrides, rule sets, scripts, and the virtual network adapter one at a time.

Mistake 5: Assuming LAN access needs no additional restrictions

allow-lan lets other devices on the same local network access the proxy on this machine. Enable it only when proxy sharing is genuinely needed, and restrict access with the listen address, firewall, and authentication settings. For ordinary single-device use, leaving it disabled is simpler and reduces port exposure.

Mistake 6: Treating the subscription URL as an ordinary public link

A subscription URL can usually retrieve the configuration associated with an account, so protect it like a login credential. When sharing troubleshooting screenshots, hide the full subscription URL, query parameters, and authentication fields in the configuration. If the URL has already been exposed, reset it in the provider's control panel instead of merely deleting local history.

7. Final checklist after installation

After the first successful connection, use the checklist below to wrap up. Complete each item before moving to the next; if a problem appears later, it will be easier to return to a known-good state.

The client version matches the system architecture, and the core starts reliably.
The subscription has updated successfully and is set as the active configuration.
The main policy groups have a usable node or an appropriate automatic policy selected.
The browser works in rule mode, and the connection list shows matched rules and policies.
The system network returns to its original state after disabling the system proxy or disconnecting the VPN.
Enable TUN only when needed, then test routing, DNS, and LAN access separately.
Set automatic updates and startup behavior according to your usage habits, and avoid switching configurations repeatedly while troubleshooting.
Subscription URLs and sensitive fields in logs are stored securely and do not appear in public screenshots.

A reliable first-install process is not about turning on every option. It is about establishing a clear known-good baseline: the original configuration loads, the system proxy works, and matched policies appear in the logs. After that, whether you add TUN, custom rules, or DNS overrides, you can quickly identify which change introduced a problem.