NetLeash shows which programs on your Windows PC use the network, right now. Block any of them, in either direction, or limit their upload and download speed. It's small, open source, and nothing leaves your PC.
For Windows 10 and 11, 64-bit. One-time purchase, no subscription, no account.
This is the real NetLeash interface, running on made-up sample traffic. Sort the list, block a program, set a limit, or open Find programs…. Nothing here touches your PC.
The everyday essentials of a per-program firewall and limiter, in one fast, local web page.
Download and upload rates, totals and a 60-second graph for every program, updated every second.
Block the connections a program makes, the ones it accepts, or both. Rules apply even while it isn't running.
Cap any program's speed in KB/s, so a big download or a cloud sync never swamps your connection again.
Every program that uses the network, listed as "Google Chrome", not as a path you'd have to look up.
Bring your NetLimiter 5 block rules and limits along, with a preview before anything changes.
How much each program downloaded and uploaded, per day, for the last 120 days.
Click a program to see its open connections: local and remote addresses, ports and state.
Starts at boot, before anyone logs in, and restarts itself if it ever stops.
A firewall sees everything your PC sends. So NetLeash is small enough to read, and it's designed so that it can't trap your PC offline.
About 4,200 lines of Rust plus one HTML page, under the MIT licence. Read it, build it, check it.
No account, no telemetry, no cloud. The interface is a web page that only your own PC can open.
Blocks and limits disappear the moment NetLeash stops, even if it crashes. It never leaves you cut off.
Monitoring and blocking use the Windows Filtering Platform and event tracing, the same machinery as Windows Firewall.
Limits use the open-source WinDivert driver. Microsoft Defender flags WinDivert as "potentially unwanted", because malware uses it too, so you add one folder exclusion yourself in Windows Security. The installer shows you how. NetLeash never changes your antivirus settings for you. Monitoring and blocking work without it.
NetLeash is a small independent project, and Windows SmartScreen warns about new programs until they've built up a reputation. Choose "More info" and then "Run anyway" to install.
No subscription and no account. Payment and invoices are handled by Lemon Squeezy, which also takes care of sales tax and VAT.
Have a download code? Redeem it here.
Prefer to build it yourself? The source code is free under the MIT licence. Buying the installer supports its development.
A 64-bit PC with Windows 10 or 11, and an administrator account to install it. NetLeash is tested on Windows 11.
Speed limits need the WinDivert driver, which Defender flags because malware uses it too. A program that adds its own antivirus exclusion behaves exactly like malware, so NetLeash asks you to do it: one folder, in Windows Security. The installer walks you through it, downloads WinDivert from its official release and checks it before installing. Skip it, and monitoring and blocking still work.
No. NetLeash itself never contacts any server. The installer connects to GitHub once to download WinDivert, and only if you choose to install it.
Your connection keeps working. Windows removes NetLeash's blocks and limits when it stops, and NetLeash restarts itself within five minutes.
Yes, NetLimiter 5's block rules and per-program limits. NetLeash shows what it will import first, and lists any rule it can't express, with the reason. NetLeash is an independent project, not affiliated with Locktime Software.
Yes. The source code is MIT-licensed, and you're free to build NetLeash yourself. The price is for the ready-made installer, and it supports further development.
Yes, within 14 days of purchase. Reply to your receipt email, or see Legal & contact.
From Settings > Apps > Installed apps, like any other program. Your rules are kept unless you choose to remove them.