simplewall

Free and open sourced! There's a portable version as well as setup version... x32 or x64... Customization interface, 17 languages, preset rules blocking Windows telemetry[619 Rules], blacklist/whitelist, customizable notifications for whitelist, dropped packet logging, in-client updates [no restart required], advanced rules such as boot-time filters [prevents leaking during boot(I recommend enabling)]... Windows firewall GUI is terrible, this is much easier to understand; much easier to edit. Previously I was using Kaspersky total security; after an account of mine was hijacked by some spyware... However during the last month of your Kaspersky license, it nags you, and is preventing windows from sleeping. Unlike paid/freemium firewalls there's nothing to nag you, no donations [in the main interface, there's a "give thanks" in the about window] or ads in the client etc. Even though it's open source they are constantly releasing builds, so no need to self compile, unless you don't trust anyone... Has an update feature, updates ask for approval, updates don't require a restart of the client. Hardware utilization Simplewall [x64] 2.4.6 Size: 1.10 MB (1,154,916 bytes) Size on Disk: 1.12 MB (1,176,120 bytes) [it's odd that windows is reporting size on disk to be larger than the size, normally size on disk is smaller] RAM usage 7.2 - 11mb depending on how many apps are listed/filters... CPU usage 0% - 0.5% [6700k] ; CPU usage when a notification is up/ when you change the interface styling

[Edited by Chaython, September 12] When there's 200 apps there's instability [hangs, when scrolling the application list]

EDIT: no longer recommend it. In v3.6.7 at some point Task Scheduler started constantly hogging the CPU when simplewall was on. Killing SW fixed the issue. At that time it's been a while since had I introduced any new firewall rules. And the dev's feedback was hollow

ORIGINAL COMMENT: Lightweight, easy to manage rules, open source. Comes with optional rules preventing Windows tracking and telemetry.

Doesn't support path wildcards. Which means that after every windows update or after application updates you must get bombarded again with notifications to allow or block applications. I personally recommend Fort Firewall as an alternative for this.

Svchost is another problem. You have svchost.exe as a entity in the apps tab , yet you also have the services that are used by the svchost on the services tab. This is where conflicts appear and you can come into some weird scenarios. Fort Firewall also has this covered.

The System rules and user rules should be merged

Also the disable on the other tabs like applications or services , is pretty useless.

You can have that application disabled in the applications tab yet if you have a user rule that is having that application as allowed , it will ignore the fact that it is disabled.

This might sound simple but after you have over 200 entries in the apps tab and a lot of rules , it makes things like the disable function completely useless

Oh and don't get me started with UWP.

Overall not the worst open source firewall but not in the top 3 either

It's simple, but sometimes that's all you need. I appreciate the ability to block microsoft analytics/telemetry. However you need to configure the default/gen settings a bit. So that enabled filters don't interfer with other software.

Old school yet powerful. I have daily driven this software for 3 years on Windows 10 no problem...

But I can't say I had the same experience with simplewall on Windows 11.

Since EVERYTHING in Windows 11 has to connect to internet (for whatever reason) and uses a new stupid design (UWP/Universal Windows Platform) which is unfortunately a CANCER to all developers because of Microsoft's policies making it hard to access/modify/control these pieces of software for any third party developer or end user. You might end up with one part of your windows (like Microsoft store) to not work correctly after receiving an update or etc...

It has many details designed for ease of use. One that no one mention is the ability to add notes, for me, it's huge. One of the main problems with the firewalls is to know if you should block one process or not, with simplewall notes you can google one time and annotate there. For me, the only drawback is that it doesn't have help.

WARNING: This program is NOT open-source, it only appears to be.

The binaries are NOT reproducible from the source code that's published on github.

All kinds of symbols are linked into the compiled executable from an external source. Functions like _r_skipuac_enable for example, and many others. The source code contains lots of these _r_xxx function calls.

Even the build.bat file calls a script from a parent directory (not included!), so the build process isn't open either.

Binaries should always be reproducible from the source code, and since this is NOT the case, this application should NOT be listed as open-source.