In a perfect world, an internet connection would be as easy as buying the equipment, signing up with an ISP, and plugging into the internet. While some manufacturers tout their plug and play functionality, anyone that has used a network knows that sometimes problems arise. While these issues may be because of slow internet service or outdated equipment, in many cases, the settings and configurations may be to blame. Anyone experiencing issues with their performance should first look to their router settings, including the fragmentation threshold.
What is the fragmentation threshold?
In short, the fragmentation threshold sets the largest Wi-Fi frame size (in bytes) that will be sent in one piece; anything larger is split into smaller fragments before transmission. It applies to unicast frames. The typical range is 256-2346, and most routers default to 2346 - effectively “off,” since that is the maximum frame size. In most cases you never need to change it. Like the related RTS threshold, it is largely a legacy 2.4 GHz tuning option that rarely helps on modern networks.
When to change the fragmentation threshold
If you do troubleshoot with it, change it on its own first, then experiment with the RTS threshold, and only then adjust the two together. Change one variable at a time so you can tell what actually helped.
In most cases it’s best to leave the fragmentation threshold alone. The main exception is a noisy, interference-prone 2.4 GHz environment with frequent collisions: smaller fragments are more likely to get through cleanly, so lowering the threshold can improve reliability. The catch is overhead - smaller frames mean more headers and acknowledgements, which reduces throughput. Lower it gradually (starting around 2304) rather than in big jumps, and stop as soon as reliability improves.
Final notes
A reliable connection sometimes takes a little tuning. Before replacing equipment or calling your ISP, it’s worth reviewing your router settings - but for most modern networks the fragmentation threshold is best left at its default. Treat it as a niche fix for a specifically noisy 2.4 GHz environment rather than a general speed booster.
