Support
Help and troubleshooting for Jitter Box.
Last updated May 19, 2026
Need help with Jitter Box? You’re in the right place.
Quick troubleshooting
“Could not connect” when I run a test
- Make sure the other Mac has “Listen for incoming tests” enabled in Settings.
- Make sure both Macs are on the same network (Wi-Fi, Ethernet, or VPN).
- Check that your firewall (System Settings → Network → Firewall) isn’t blocking incoming connections on the port you picked (default 7878).
- Try the receiver’s IP address (e.g.
192.168.1.42) instead of its hostname — some routers don’t expose.localBonjour names.
“The numbers look too low”
- The test reports the actual speed of the link between the two Macs. Wi-Fi is often slower than your ISP plan, especially in a busy 2.4 GHz channel or far from the router. Try Ethernet on one or both ends to see what the wired link can do.
- 4 parallel TCP streams saturate gigabit easily; if you have a 10 Gbps link, try increasing “Parallel streams” to 8 or more in Settings.
“The receiver toggle won’t stay on”
- The first time you enable the receiver, macOS may ask for Local Network permission. Open System Settings → Privacy & Security → Local Network and make sure Jitter Box is on the list and switched on.
- If you’re running Jitter Box out of
~/Downloadsand macOS shows a Gatekeeper warning, move the app to/Applicationsand reopen it (right-click → Open the first time).
“Launch at login” doesn’t work
- Open System Settings → General → Login Items & Extensions and make sure Jitter Box appears under “Open at Login” with its toggle on. If the toggle was previously denied, the in-app switch in Jitter Box’s Settings can’t override that — you have to re-enable it in System Settings first.
Frequently asked
Does it work over a VPN?
Yes, as long as the two Macs can see each other on the VPN’s address
space. The app uses plain TCP, so any VPN that routes a /24 of
addresses between peers will work.
Does it work over the public internet?
In theory yes — if the receiver Mac is reachable on its public IP and the relevant port is forwarded. In practice, the app is designed for LAN use; running a public-facing speed test receiver has obvious security implications and is not officially supported.
Will it test against speedtest.net or fast.com?
No. By design Jitter Box only talks to other Jitter Box installs (or the free companion Go CLI that speaks the same protocol). The whole point is to measure the link you actually care about, not the path to a server in someone else’s data centre.
What’s the data I see in “History”?
Every test you’ve ever run, with the four headline numbers (ping, jitter, download, upload), the host you tested against, and the date. All stored locally on your Mac; nothing leaves the device.
Contact
Email: help@jitterbox.app
— Cloudmanic Labs, LLC