Slowy adventure has ended

I am really sorry to say that, but Slowy is not and will never be OSX 10.10 Yosemite compatible. Stating with Yosemite, Apple has decided to remove the system tool (ipfw) that Slowy used to alter the network connection. The newcomer, pf, is more powerful but it is missing some of the key features that Slowy needs.

Moreover, on the web developers side, Chrome 38 now integrates a network throttling tool straight into DevTools. And for all of you interested in OSX bandwidth management IceFloor does the job for free.

In order to thank all contributors, the full version of Slowy is now completely free to download.
Thank you all so much and see you on my next project.


Slow down your internet connection

Slowy is a tool which simulates custom connection’s conditions and limits the network traffic to a specified destination port or interface. It is created for web developers, like me, who need to test a website with a real-world connection, even on a local server.

Preview of Slowy app

Slowy is an OSX MenuBar app, so it is lightweight and is placed only on the system topbar.


Multiple network presets (5 included)

With Slowy you can simulate multiple network conditions. Moreover, the app includes five built-in presets for the most common usecases. The presets included are: 56K, EDGE, 3G, LTE/4G and DSL.

Slowy preference window for bandwidth throttling

Custom bandwidth limit, latency,
packet loss rate and port

Each preset has its own settings. You can setup: bandwidth [kbit/s], packet loss rate [%], packet latency [msec] and the destination port. Moreover, you can limit downlink and uplink speeds selectively.

Lightweight and unobtrusive

As Slowy mainly is a GUI for built-in OSX tools, it will occupy only few MB of your RAM and nearly 0% of your CPU. Moreover, Slowy is not a proxy so you do not need to change the address on your browser.

Slowy restricts the network traffic
only to one port or interface

Slowy has the ability to apply the network preset only to the traffic to the selected port. This means that it will not affect other services. Moreover Slowy now can throttle the connection only on one interface.