I wrote FritzGraph: a small always-on-top speed graph for your Fritz!box, Multilangual. Tested on FB7590.
Hi all,
With the help of Claude (and building it with Visual Studio 2026 Community edition) I built a small Windows tool that shows the live download and upload speed of a Fritzbox as an always-on-top graph and I'd like to share it with you. I use it with a Fritzbox 7590 on my fibre connection on the Glaspoort network with Freedom as ISP, but it only reads the router's UPnP status, and so it should work with other models too.
Widget view of the application
What it does:
- Two live graphs (download and upload) in a small, resizable window, borderless by default so it looks like a widget. Double-click to toggle the title bar and menu bar.
- Optional tray icon in several flavours: the program icon, speeds as text, two small bars (download left, upload right), or two separate tray icons, one for download and one for upload, each with an arrow and unit.
- Dark and light theme (the tray icons follow it), adjustable opacity, refresh rate and time span.
- Scale follows the visible graph, or the highest value since start. Optionally the same scale for download and upload.
- Options to start the appication with Windows
- Menu-item that leads to the Speedtest.net website.
- Languages: English, Dutch and German. It follows the Windows display language and falls back to English if no Windows display language meets the 3 languages of the application.
Single systray icon with speed bars relative to widget graphs
How to configure to read the correct IP address of your Fritzbox:
Rightclick on the widget or systray icon and choose the menu option "Fritzbox address...".
As an alternative you can doubleclick the widget and at the menu that shows up go to Settings > Fritzbox address...
How it talks to the Fritzbox:
It polls the UPnP service (GetAddonInfos) on port 49000 and reads the current send/receive rate. No password and nothing is sent to the internet. You only need to enable this in the Fritzbox: Home Network > Network > Network Settings > More Settings (Heimnetz > Netzwerk > Netzwerkeinstellungen > Weitere Einstellungen) > "Transmit status information over UPnP".
Requirements: Windows 10 or 11 and the .NET 10 Desktop Runtime.
Screenshot of the white theme in window mode
It is in beta right now and I can not guarantee a correct working of it. Feel free to play around with and provide feedback.
You can download it from my Stack Storage here: https://joen.stackstorage.com/s/7pLiTflx4xqqXVtY