simplewall review: block apps until you allow them

simplewall is a free open-source Windows firewall for people who want to choose which programs on a PC may use the network.¹ Henry++ publishes it as a tool that configures Windows Filtering Platform, the Windows services other programs use to allow or block network traffic.¹⁶ By default it blocks every application, so a program stays offline until you allow it.¹

Last checked October 28, 2026.

At a glance

What it is: A free open-source Windows firewall that blocks applications until you allow them

Works on: Windows 7 SP1, 8, 8.1, 10 and 11, 64-bit and ARM64¹

Price: Free¹

Licence: GPL-3.0⁴⁵

Best for: Windows users who want every program blocked until they allow it

Official site: github.com/henrypp/simplewall

What simplewall does (and how it protects your privacy)

simplewall configures the Windows Filtering Platform (WFP).¹ Microsoft describes WFP as a set of API and system services for building network filtering applications, and as a development platform rather than a firewall itself. Windows Firewall with Advanced Security, the firewall in Windows Vista, Windows Server 2008, and later, is implemented with WFP.⁶ simplewall uses that platform on its own. The project says it is not a control panel for Windows Firewall, and that it does not interact with Windows Firewall.¹

In the default setup, simplewall blocks all applications, and you allow the ones you want online.¹ Those filters keep working after you close the program.¹ Traffic you allow still travels on the network you are using. What an internet provider can still see is a separate question from which program you allowed.

The project also ships an internal blocklist, described as a way to block Windows spy and telemetry.¹ Telemetry means reports a system sends about how it is used. WindowsSpyBlocker, the list linked from simplewall, says those rules sit in blocklist.xml and are used by default.⁷ Settings, then Blocklist, then Disable turns the list off.¹ The rules editor can cover every program, or only the ones you pick, by address, port, range, or IPv6 address.¹

Key features of simplewall

A default block. Every application is blocked until you allow it.¹
Your own rules. A global rule covers all applications. A special rule covers only the ones you choose. Addresses, ports, ranges, and IPv6 fit in the rule syntax.¹
A Windows blocklist you can switch off. The built-in list is described as blocking Windows telemetry, and Disable turns that list off.¹⁷
A record of blocked and allowed traffic. Dropped packets can raise a notification and be written to a file on Windows 7 and later. Allowed packets can be logged on Windows 8 and later.¹
Services, Store apps, and Linux-on-Windows. simplewall can cover Windows services, Microsoft Store apps on Windows 8 and later, and Windows Subsystem for Linux.¹
Rules that last, or rules that reset. Permanent rules stay until you disable them. Temporary rules clear at the next reboot.¹
An installer or a portable copy. Portable mode uses a simplewall.ini file next to the program, or the copy kept in your user folder. Installed filters keep working when simplewall is closed.¹

Pros and cons of simplewall

Pros

The download is free, and the source is published under the GNU General Public License, version 3.¹⁴
The default blocks every application, so new programs stay offline until you allow them.¹
You can leave Windows Firewall on. The project says the two work independently.¹
The filters keep working after you close the window, and the telemetry blocklist can be switched off.¹
The project is still updated. The changelog lists 3.9.1 as a beta on 22 July 2026, the repository is not archived, and the last push was on 28 October 2026.²⁵

Cons

The project describes simplewall as definitely for advanced users.¹
It runs on Windows 7, 8, 8.1, 10 and 11, 64-bit or ARM64. A phone, a Mac, or a Linux PC needs a different tool.¹
The project says administrator rights are required.¹
The default block can stop Windows Update until you allow it. On Windows 10 and later, use Settings, then Rules, then Allow Windows Update.¹
Uninstalling leaves the filters in place until you open simplewall and press Disable filters.¹
Version 3.9.1, dated 22 July 2026, is listed as a beta. The latest version listed without that label is 3.8.7, from 8 August 2025.²

Is simplewall safe and private?

Henry++ is the developer named on the project, with a copyright line covering 2016 through 2026.¹ The source is public under the GNU General Public License, version 3, which GitHub records as GPL-3.0.⁴⁵ The repository is not archived, and it was pushed on 28 October 2026.⁵

Filters stay on that computer after you close simplewall, and they remain after an uninstall until you disable them.¹ Settings normally live in simplewall.ini under your user folder, in Henry++\simplewall. Portable mode keeps that file next to the program.¹ The 3.8.7 release publishes simplewall-3.8.7-setup.exe.sig beside the installer.³ The project says each binary carries a GPG signature named simplewall.exe.sig, and it publishes the fingerprint D985 2361 1524 AB29 BE73 30AC 2881 20A7 5635 B5FD.¹

The notes for version 3.8.6 say the check for updates was fixed so it does not bring up a popup.²

How to get started with simplewall

Download version 3.8.7 from the official 3.8.7 release. Choose simplewall-3.8.7-setup.exe, or the portable archive simplewall-3.8.7-bin.7z. The signature file simplewall-3.8.7-setup.exe.sig is published with the installer.³ The changelog dates 3.8.7 to 8 August 2025, and dates 3.9.1, which adds network statistics about speed, as a beta on 22 July 2026.²
Administrator rights are required. Run the installer, or start the portable program, with those rights.¹
For a first try, choose temporary rules. They reset after the next reboot. Permanent rules stay until you disable them.¹
Allow the programs you use. Everything else stays blocked.¹ On Windows 10 and later, if updates cannot download, open Settings, then Rules, then Allow Windows Update.¹
Leave Windows Firewall on. The project says you do not need to disable it.¹
Leave the blocklist on, or open Settings, then Blocklist, and choose Disable.¹
If you remove simplewall later, open it first and press Disable filters. Otherwise the filters remain after uninstall.¹

Who should use simplewall (and who might prefer something else)

simplewall fits a Windows user who wants approved programs online and everything else blocked, even after the window is closed.¹ The project says it is definitely for advanced users. Temporary rules are a gentler first try, because a reboot clears them.¹

On a Mac, LuLu reviews outgoing connections. On Linux, OpenSnitch reviews which applications connect. On Android, NetGuard chooses which apps get internet access. If you want only the firewall Windows already includes, Microsoft documents Windows Firewall with Advanced Security as the firewall built into Windows Vista, Windows Server 2008, and later.⁶ simplewall is the extra step when you also want each application blocked until you allow it, with Windows Firewall left on.¹

Frequently asked questions

Is simplewall free?

Yes. The project lists it as free and open source, and the licence is the GNU General Public License, version 3.¹⁴ The same page has a donate section, including PayPal, for people who want to support the work.¹

Is simplewall safe?

The source is public under GPL-3.0, Henry++ develops it, and the repository was updated in October 2026.¹⁴⁵ The 3.8.7 installer is published with a signature file, filters stay on the PC, and the project says administrator rights are required. The default blocks every program until you allow it.¹³

Does simplewall work on Windows 11 or iPhone?

Yes on Windows 11, in 64-bit and ARM64, and on Windows 7 SP1, 8, 8.1 and 10.¹ On Windows 7, the project says updates KB2533623 and KB3063858 were required.¹ Those requirements do not list iPhone. For an Android phone, NetGuard is the matching idea.

Do I need to turn off Windows Firewall?

No. The project says simplewall is safe to use with Windows Firewall, that you do not need to disable it, and that the two work independently.¹ Its filters also keep working when simplewall itself is closed.¹