Split Tunneling Explained: Which Traffic Goes Through the VPN and Which Doesn't?

When you use a VPN, have you ever wondered: does all my traffic really have to go through the tunnel? Actually, no. Split tunneling is exactly for this—it lets you decide which apps and which websites go through the VPN and which connect directly to the local network. Done right, you get faster speeds and a smoother experience.

This article breaks down split tunneling: how it works, who it's for, how to configure it, and which pitfalls to avoid.

What exactly is split tunneling?

Simply put, a regular VPN is "global mode": every network request on your device is encrypted, sent to the VPN server, and only then reaches the target website. The upside is consistency and peace of mind; the downside is that local websites also take a detour, which can increase latency.

Split tunneling, on the other hand, is "on-demand routing." You can specify that certain traffic goes through the VPN while the rest uses your local broadband. For example, route streaming and overseas work systems through the encrypted tunnel, while WeChat, online banking, and local video sites connect directly.

Technically, it's usually implemented through routing tables, app whitelists/blacklists, or domain rules. Support varies by system—Windows, Android, and macOS each have their own implementations.

Which traffic should go through the VPN, and which can skip it?

There's no standard answer, but you can categorize by need. Here's a reference list:

• Recommended through VPN: Overseas streaming, cross-border office systems, browsing where you need to hide your real IP, and sensitive operations on public Wi-Fi.
• Can skip VPN: Domestic video sites, local cloud drives, banking/payment apps, LAN devices (printers, NAS), and online games (depending on server location).
• Depends: Download tools, cloud sync, video conferencing—it depends on where the servers are and how sensitive you are to latency.

For example: you work from home and need to access your company's overseas intranet while also joining a domestic video conference. With global proxying, the meeting might lag; with split tunneling, you point the intranet domain to the VPN and let the meeting traffic connect directly—both sides work smoothly.

The benefits and costs of split tunneling

The benefits are straightforward. First, speed: local traffic doesn't take a detour, so pages load faster. Second, bandwidth savings: less load on the VPN server. Third, compatibility: some local services (smart home devices, banking USB keys) are sensitive to proxies, and direct connections are more stable.

There are costs too. Split tunneling is more complex to configure than global mode, and miswritten rules can cause "what should go through doesn't, and what shouldn't does." Also, directly connected traffic isn't protected by VPN encryption, so be extra careful on public networks.

One often overlooked point: DNS leaks. With split tunneling, if DNS queries aren't handled properly, the domains you visit may be exposed. When choosing a client, check whether it has DNS handling mechanisms.

How to configure it? The approach matters more than the steps

Client interfaces vary widely, but the logic is the same. There are generally three routing methods:

1. App-based routing: Choose which apps go through the VPN—suitable for mobile and desktop.
2. IP/domain-based routing: Point specific domains or subnets to the tunnel—suitable for users with clear targets.
3. Region-based routing: Domestic IPs connect directly, foreign IPs go through the VPN—many clients have built-in rules for this.

If you don't want to fiddle with rules, prioritize clients with "smart routing." lightxtreme VPN provides routing-related settings in its client, so you can switch by scenario without manually writing routing tables. Before configuring, think clearly: what are your three most-used overseas services? Add them to the proxy list, let everything else connect directly for a few days, then fine-tune.

Security reminder: don't leave what should be protected out in the open

Split tunneling isn't "the more split, the better." When connecting to public Wi-Fi at a café, temporarily switch back to global mode—don't let login and payment traffic run unprotected. The same goes for handling sensitive files on business trips: fewer direct-connect rules means more security.

Also, review your split tunneling rules regularly. System updates and app redesigns can render old rules ineffective. If a website suddenly becomes slow or won't open, first check whether it was mistakenly routed to direct connection.

Should you use split tunneling? It depends on your habits

If you only occasionally look things up or watch videos, global mode is hassle-free enough. But if you switch between domestic and overseas services every day, split tunneling can noticeably improve your experience—especially in latency-sensitive scenarios.

If you want to try it, start with the basic rule "domestic direct, overseas through VPN," and once that runs smoothly, refine by app. lightxtreme VPN's client supports switching connection modes by scenario, with a low learning curve—great for practicing split tunneling. After downloading, don't rush to change a bunch of rules; run with the default smart routing for a day, see which traffic needs adjustment, and then make changes.