What Is VPN Split Tunneling? How It Works and the Risks

VPN split tunneling is a setting that sends some of your traffic through an encrypted VPN tunnel while the rest goes straight to the internet over your normal connection. You choose by app, website or IP address. It can fix a printer that vanished, an app that refuses VPN connections or a laggy video call, but anything outside the tunnel loses the VPN's protection and shows your real IP address. At home, that is a reasonable trade for low-risk apps. On public Wi-Fi, or on a work device without IT approval, keep a full tunnel.

What Is VPN Split Tunneling?

A VPN tunnel is an encrypted connection between your device and a VPN server. By default, most VPNs push everything through it. Windows treats force tunnel as the default when no routes are specified, and Android sends all traffic through the VPN unless the app sets up lists of included or excluded apps.

Split tunneling breaks that default on purpose. The NIST glossary describes it as routing organization-specific traffic through the VPN and other traffic through the user's default gateway. In home use, the idea is the same: some traffic takes the tunnel, and the rest behaves as though the VPN were off.

	Full tunnel	Split tunnel
Traffic in the VPN	Everything	Only what your rules select
Address websites see	The VPN server's	The VPN server's for tunneled traffic; your real IP for direct traffic
What your Wi-Fi or ISP can see	That you are connected to a VPN	That, plus the destinations of direct traffic
Speed	All traffic detours through the VPN server	Direct traffic skips the detour
Printers and home devices	May become unreachable	Can stay reachable
Employer visibility on a work VPN	The company can inspect internet traffic	The company cannot inspect direct traffic

Full tunnel sends all traffic through the VPN; split tunnel sends chosen traffic through it and the rest directly

Split tunneling never adds protection. It removes protection from selected traffic in exchange for speed or compatibility, so the only real question is whether that traffic needs it.

How Split Tunneling Works

Your device keeps a routing table, a list of rules that decide which network connection each piece of traffic leaves through. A full tunnel adds a default route, such as 0.0.0.0/0, that points at the VPN. Anything without a more specific rule goes into the tunnel.

A split tunnel changes those rules in one of three ways:

By destination. The VPN adds routes only for named address ranges. In AWS's example, only traffic for 172.31.0.0/16 enters the tunnel.
By app. The operating system assigns whole apps to the VPN or to the normal network. On Android, a disallowed app uses system networking as if the VPN were not running.
By domain. The VPN client looks up the site's IP address and adds a route for it. Cisco's dynamic split tunneling does this at runtime because cloud addresses change.

Routing and name lookups are separate. Cloudflare's documentation warns that its split tunnel rules only affect IP traffic, and that DNS requests follow their own settings. A site can sit outside the tunnel while its DNS lookup stays inside, or the reverse.

Types of Split Tunneling

Type	What the rule matches	Typical use	Main limit
By app	An installed app	Exclude a game or a video call app	Every connection from that app takes the same path
By website or URL	A site's domain name	Exclude one site that blocks VPNs	Some traffic has no URL, and domain rules depend on DNS
By IP address or route	A destination address range	Send only company networks through the VPN	Needs stable, published addresses
Dynamic	A hostname resolved while connected	Cloud services whose addresses change	Support varies by VPN client
Local network access	Addresses on your own network	Reach a printer or home storage	A known target for leak attacks

Two details matter when choosing. Microsoft notes that Teams media traffic has no URL, so URL rules cannot route it. Cloudflare recommends IP rules over domain rules when possible, and says mobile clients apply rules only when the tunnel starts.

Include Lists, Exclude Lists and the Word Inverse

Every split tunnel uses one of two list types. With an exclude list, everything uses the VPN except what you name. With an include list, nothing uses the VPN except what you name. Android's allowed and disallowed lists work this way, and an app can use one or the other, not both.

The confusing part is the word "inverse." Many consumer VPN apps call their exclude list "split tunneling" and their include list "inverse split tunneling." Wikipedia's entry, which cites enterprise gateway documentation, defines inverse as the opposite: everything enters the tunnel except explicit exceptions. Both meanings are in active use, so the label tells you very little.

Exclude lists tunnel unlisted traffic and include lists send it direct, while the word inverse is used for both

Ask one question instead: where does traffic go when no rule mentions it? If the answer is "through the VPN," a forgotten app stays protected. If the answer is "direct," a forgotten app is exposed, and you may not notice.

Why People Use Split Tunneling

To reach local devices. Printers and home storage can disappear while a VPN is on.
To keep an app working. Some websites and apps refuse connections from known VPN addresses.
To get local results. Sites that use your location see the VPN server's location unless they are excluded.
To reduce lag. Games and video calls avoid the extra trip through the VPN server.
To protect company VPN capacity. Microsoft says customers reported that internal traffic fell from around 80% of their total to 20% or lower by 2020, which left VPNs carrying cloud traffic they were never sized for.

Is VPN Split Tunneling Safe?

It can be, for the right traffic on the right network. Split tunneling is not a vulnerability. It is a decision to leave some traffic outside the VPN, and the risk depends on what that traffic is and who runs the network it crosses.

What changes	What it means	What to do
Direct traffic loses VPN encryption	Protection now depends on the app or website using its own encryption	Exclude only apps and sites that use HTTPS
Your real IP address is visible	The destination can see your address and rough location	Do not exclude anything you use the VPN to keep private
The network can see destinations	HTTPS hides content, not which server you contacted	Avoid excluding sensitive services on networks you do not trust
DNS may leave the tunnel	Your ISP or resolver may see the names you look up	Check your VPN's DNS setting
Browsers may reveal your ISP address	WebRTC can discover both addresses on a split tunnel	Test your browser after enabling it
A kill switch may not cover excluded apps	They may stay online when the VPN drops	Disconnect the VPN once and watch what happens

The HTTPS point deserves context. The FTC said in February 2023 that public Wi-Fi is usually safe because most websites now use encryption. The NSA's guidance is stricter: it strongly advises a VPN on public Wi-Fi, HTTPS browsing and avoiding bank or medical accounts there. Both are right about different threats, and a fake site can still have a padlock. Researchers behind the TunnelCrack work add the limit that matters here: HTTPS does not hide who you are talking to.

The browser point comes from the IETF. RFC 8828 says WebRTC can discover both the VPN address and your ISP address on a split-tunnel VPN. Our proxy, VPN and Tor comparison covers DNS and WebRTC leaks in more depth.

A Full Tunnel Can Leak Too

Turning split tunneling off does not guarantee that everything stays in the tunnel. Two pieces of research show why, and both abuse the routing table described above.

TunnelCrack (August 2023). Researchers from KU Leuven, NYU and NYU Abu Dhabi tested more than 66 VPNs on five platforms. Their LocalNet attack abuses the local network exception most VPNs include, so a malicious Wi-Fi network can pull traffic out of the tunnel by posing as local. All iOS apps tested were vulnerable, along with all but one on macOS and about a quarter on Android. A second attack, ServerIP, relies on DNS spoofing. These results describe the products as tested in 2023, and some vendors have since patched.
TunnelVision (May 2024). CVE-2024-3661 describes how an attacker on the same local network can use DHCP option 121 to add routes that force traffic outside a VPN. Leviathan Security Group, which published the research, reported that the VPN still shows as connected and kill switches never trip, and that Android is not affected because it does not implement that option.

Both are forms of man-in-the-middle attack. They need an attacker on your local network, or at your ISP in the case of ServerIP. The TunnelCrack researchers advise updating your VPN app, disabling local network access if the app offers that option, and relying on HTTPS. The FCC adds that your phone's data plan may be more secure than Wi-Fi when you send sensitive information.

Should You Use Split Tunneling?

This table is our editorial guide, based on the sources above.

Your situation	Recommendation	Why
A printer or home storage stopped working on your home network	Use it, or turn on the VPN's local network option	Low risk on a network you control
A game or video call lags at home	Exclude that one app	The app's traffic is usually low sensitivity
A site or app refuses your VPN connection	Exclude only that app, and check that it uses HTTPS	Better than turning the whole VPN off
You are on airport, hotel or cafe Wi-Fi	Keep a full tunnel, or switch to mobile data for the blocked app	You do not control the network
You use the VPN to hide your activity from your ISP or a network owner	Keep a full tunnel	Direct traffic reveals exactly what you want to hide
You are on a work laptop or work VPN	Follow company policy and do not change it yourself	The setting may be a contract or security requirement

If you use split tunneling, prefer an exclude list and keep it short. That way, new apps stay protected by default.

How to Turn On Split Tunneling and Check It

Menu names vary, so these steps are general. Look for "split tunneling," "bypass," "app exclusions" or "route via VPN."

Open your VPN app's settings and find the split tunneling option.
Check whether it uses an exclude list or an include list.
Add the fewest apps or sites that solve the problem.
Reconnect. On Android, lists must be set before the connection starts.
Verify it with the steps below.

Platform	Where the control lives	Good to know
Windows	The VPN app, or the SplitTunneling setting on a built-in VPN profile	Built-in profiles force all traffic through the tunnel by default
macOS	The VPN app, or the "Send all traffic over VPN" option on built-in profiles	Clearing that option may also require adding routes by hand
iPhone and iPad	The VPN app	Per-app VPN is a managed-device feature, so consumer options vary by app
Android	The VPN app	Block connections without VPN can cut off apps when lists are in use
Company VPN	The administrator's policy	Users normally cannot and should not change it

The platform details come from Microsoft's Set-VpnConnection reference, Cisco Meraki's client VPN guide, Apple's VPN deployment overview and Android's VPN guide.

To check the result, compare your public IP address in a tunneled browser and in an excluded app or browser. They should differ. On a computer, you can also read your routing table. These commands only display information and change nothing:

text

# Windows
route print

# macOS
netstat -rn -f inet

# Linux
ip route show

With a full tunnel, the default route points at the VPN interface. With an include-list split tunnel, the default route stays on your normal connection and only named networks point at the VPN. App-based rules may not appear here, so rely on the IP comparison for those.

Frequently Asked Questions

Should I turn on split tunneling?

Only if you have a specific problem to solve, such as a blocked app or an unreachable printer. If nothing is broken, leave it off, because a full tunnel covers apps you forget about.

Why is split tunneling considered bad?

It is not bad in itself, but it leaves traffic outside the VPN. Companies dislike it because they cannot inspect that traffic, and because a compromised laptop can talk to the internet and the company network at the same time.

Does split tunneling make my internet faster?

It can make excluded apps faster, because their traffic skips the trip through the VPN server and its encryption. The gain depends on your VPN server and connection.

Should I exclude my banking app?

Only if the app refuses to work over your VPN. If you must, do it on a network you trust or use mobile data. The NSA advises against accessing bank accounts on public Wi-Fi.

Is a split tunnel the same as a kill switch?

No. A kill switch blocks traffic when the VPN drops. Split tunneling decides which traffic uses the VPN while it is up. Excluded apps may keep working during a drop because they were never in the tunnel, and behavior varies by app.

Can my employer see traffic outside the tunnel?

Not through the VPN gateway. NIST notes that split tunneling stops the organization from examining much of that traffic. Software on a company-managed laptop may still record activity, so check your employer's policy.

What is the difference between split tunneling and per-app VPN?

Per-app VPN is one way to split traffic: the rule matches an app rather than an address. Apple and many enterprise platforms use the term for managed apps, while split tunneling is the broader term.

For Organizations: Policy, Testing and Detection

For a company, the question is not speed alone. A split tunnel changes which security controls see remote traffic, and that needs an owner and a test.

Where the Guidance Disagrees

Source	Position	Scope
NIST SP 800-53 Rev. 5, SC-7(7)	Prevent split tunneling unless securely provisioned with defined safeguards	Moderate and high federal baselines
NIST SP 800-46 Rev. 2	Consider disabling it on untrusted networks such as hotspots	Telework guidance
NIST SP 800-171 Rev. 2, 3.13.7	Prevent it, with no stated exception	Controlled unclassified information
CMMC Level 2, SC.L2-3.13.7	Same requirement	US defense contractors
NIST SP 800-171 Rev. 3 (2024)	Requirement withdrawn; addressed by remote access and configuration requirements	Newer revision, not the CMMC baseline
Australian Cyber Security Centre (2021)	Devices should disable it	General guidance
CISA TIC 3.0 telework guidance (2020)	May be considered, if decision points cannot be easily bypassed	US federal agencies
Microsoft (page updated June 2026)	Recommends it for a narrow set of Microsoft 365 endpoints	Microsoft 365 customers

The Rev. 3 detail catches people out. CMMC's rule at 32 CFR 170.14 says Level 2 requirements are identical to Rev. 2, so Rev. 3's withdrawal does not relax the rule for those contractors. Confirm your contract language with your assessor. For the other positions, see SP 800-53, SP 800-46, the Australian guidance and CISA's telework guidance.

Microsoft's case is narrow on purpose. It targets endpoints that it says carry around 70-80% of Microsoft 365 traffic, in about 20 IP subnets, with encryption and security controls in the service. It describes five models, and recommends the second. Keep in mind that Microsoft sells the service it is advising on.

Five VPN models compared: forced tunnel, few exceptions, broad exceptions, selective tunnel and no VPN

What a Defensible Policy Includes

Keep the default route in the tunnel. Allow a short list of named exceptions, not "everything but the office."
Use IP ranges where they are published. Microsoft advises against FQDN rules for its endpoints because they may not cover key scenarios.
Lock it. SC-7(7) describes pre-approved addresses "without user control," and users should not be able to edit the list.
Prevent bridging. NIST warns that a device with two active interfaces can become a bridge between trusted and untrusted networks.
Replace what you lose. Direct traffic skips the proxy, so endpoint detection, identity controls and zero trust access have to cover it.
Assign an owner and a review date. Exception lists grow quietly. Remote work risks change too.

Also remember that the VPN gateway is itself a target. CISA and the NSA warn that exploited remote access VPN servers can lead to credential theft and remote code execution.

How to Validate It

A policy document proves little until someone tests it. On systems you own or are authorized to test:

Inspect a managed laptop. Confirm the routes, DNS servers and exception list match the policy, and that a standard user cannot change them.
Test on a hostile network, in a lab. Connect test devices to an isolated network with an untrusted DHCP server and confirm whether traffic stays in the tunnel.
Assume the laptop is compromised. The Australian guidance warns that split tunneling could let attackers interact with the company network in real time. An internal penetration test from a VPN-connected device shows what they could reach, and whether lateral movement is contained.
Check detection. Generate harmless direct traffic to a test domain from a split-tunneled device, and confirm that endpoint or DNS monitoring records it. If your only visibility is the proxy, you will see nothing.

A network penetration test can include VPNs in scope. If you want an outside view of your remote access setup, see our penetration testing services or contact our team to discuss scope.

About The Author

Mohammed Khalil is a Cybersecurity Architect at DeepStrike, specializing in advanced penetration testing and offensive security operations. With certifications including CISSP, OSCP, and OSWE, he has led numerous red team engagements, focusing on cloud security, application vulnerabilities, and adversary emulation. His work involves dissecting complex attack chains and developing resilient defense strategies for clients in the finance, healthcare, and technology sectors.