TCP Optimizer: tune your Windows connection without digging through the registry
Your connection is paying for a fast line, but downloads never seem to reach it. Windows ships with general-purpose TCP/IP settings, and fixing them by hand means editing the registry and running netsh commands you may not trust yourself with. TCP Optimizer from Speed Guide puts those settings in one window.
Quick facts
- Version: 4.1.1
- Platforms: Windows, from XP up to Windows 11, plus several Windows Server editions
- Price: free
- Installation: none; you download it and run it as administrator
- Size: about 668 KB
Key features
Pick the right TCP Window for your connection speed
The program uses the bandwidth-delay product to find the best TCP Window for your line speed, so you aren't guessing at RWIN values.
Change MTU, QoS and ToS/Diffserv settings from one screen
You get to the related TCP/IP parameters, including MTU and the more advanced QoS and ToS/Diffserv prioritization, without hunting through Windows dialogs.
Test latency and find your largest packet size
Built-in tools measure average latency across multiple hosts and find the largest possible packet size (MTU), so you can check a change took effect.
Back up your settings and return to the Windows defaults
You can back up your current settings and restore the Windows defaults, which makes experimenting much less risky.
Apply tweaks through the registry, netsh and PowerShell
Version 4 applies changes using the Windows Registry, netsh commands and PowerShell cmdlets. Settings differ a little between Windows versions, so the vendor publishes separate documentation for older Windows (9x to XP) and for Windows 7 and later.
Who it's for
It suits anyone who wants to tune a broadband connection without editing the registry by hand. The vendor says it aims at broadband but can help with any connection type, from dialup to Gigabit and faster. Beginners can use it as is. Advanced users get access to the deeper parameters.
Pros and cons
- Pro: free, tiny, and needs no installation.
- Pro: backup and restore-to-default options make changes reversible.
- Pro: covers a long list of Windows versions.
- Con: it changes low-level network settings, so you need to run it as administrator and read the documentation for your Windows version.
- Con: the legacy 3.08 build is deprecated and doesn't support Windows 8 or 10. Use version 4 on current systems.
- Con: it is Windows-only.
FAQs
Is TCP Optimizer free?
Yes. The vendor describes it as completely free, and says it can be redistributed as long as credit is given and it isn't sold for profit.
Do I need to install it?
No. You download it and run it as administrator.
Will it work on Windows 10 or 11?
Yes, version 4 is the build for current Windows. Version 3.08 is a deprecated legacy build for Windows 7 and earlier.
Can I undo changes?
Yes. You can back up your current settings first and restore the Windows defaults later.
System requirements
Windows XP through Windows 11, and Windows Server 2008, 2012 and 2019. Run it with administrator rights.