Swisscom Speed Test

This diagnostic utility validates the throughput of your Swisscom blue Internet connection. To interpret your results, you must identify your technology type. Fiber (FTTH) uses the OTO socket and offers symmetrical speeds up to 10 Gbps via XGS-PON. Copper (FTTS/FTTB) utilizes g.fast technology, which pushes incredibly high speeds (up to 500 Mbps) over short copper telephone lines, but remains physically limited by distance and old in-house wiring.

Understanding Your Speed Metrics

When analyzing your connection integrity, focus on these three performance vectors:

Download Throughput:
• Fiber (10 Gbit/s): To test this, you need the Internet-Box 3 or 4 and a computer with a 10G Ethernet port plugged into the router's 10G LAN port. On standard equipment, seeing 940 Mbps is a "Pass."
• g.fast (Copper): Speeds are highly variable (e.g., 200-500 Mbps). If you lose sync often, your old telephone wiring likely lacks a "Digital Microfilter."

Upload Throughput:
• Fiber: Symmetrical. 1 Gbps Down = 1 Gbps Up.
• Copper (g.fast): Asymmetrical. A 500 Mbps download plan might only deliver 100 Mbps upload. This is a physical limitation of the copper spectrum.

Latency (Ping): Swisscom Fiber is extremely low latency (2ms to 5ms to Zurich IX). If you see high ping on Fiber, it is almost certainly a Wi-Fi issue, not a line issue.

What Results Should You Expect?

The "Internet-Box" Hardware Factor

Your router generation determines your maximum test speed. Benchmarks include:

Internet-Box 4 (Fiber Only): Includes a 10 Gbit/s LAN Port. You must use this specific port (often labeled with a "10" or distinctive color) for multi-gigabit speeds.

Internet-Box 3: Also supports 10 Gbit/s WAN/LAN. Features Wi-Fi 6.

Internet-Box 2 / Standard: Legacy units. These physically limit any connection to 1 Gbps. If you pay for the "XL" plan with this box, you are wasting money.

Why Is Your Swisscom Connection Slow?

Before calling the hotline (0800 800 800), verify these common Swiss infrastructure faults:

The "Bridge Mode" Issue: Swisscom Internet-Boxes do not support true Bridge Mode. If you plug your own router (e.g., UniFi) into the Internet-Box, you create "Double NAT." You must configure the DMZ function or "IP Passthrough" in the Swisscom router settings to fix gaming/VPN issues.

OTO Socket Dust: The fiber socket (OTO) is sensitive. If you unplug the fiber cable and let the tip touch the carpet, microscopic dust will block the light signal, dropping speeds from 10 Gbps to ~100 Mbps or causing disconnects.

WLAN-Box Placement: If you use the Swisscom WLAN-Box (Repeater), it must be connected via Ethernet for best results. If used wirelessly, ensure the LED is solid white, not blinking red (weak signal).

Swisscom Technical Configuration Data

How to Get an Accurate Test

Wireless testing cannot validate 10 Gbit/s lines.

To confirm the actual speed delivered to your home:
1. Use a PC with a 10G Network Card (NIC).
2. Use a Cat6a Ethernet cable (Cat5e is not enough for 10G).
3. Plug into the 10G LAN Port of the Internet-Box 3/4.
4. Run the Swisscom Speedtest (available directly within the router interface at http://internetbox.home) to test "Router-to-Server" speed, eliminating your PC as a variable.

When to Call Support

Escalate the issue to Swisscom if you observe these specific failures:

Red LED (Internet): The router cannot synchronize. For Fiber, check if the fiber cable is clicked firmly into the OTO socket.

Flashing White/Red: The router is updating or provisioning. Wait 15 minutes.

Activation Fail: If you plugged into a new OTO socket (e.g., Port 2 instead of Port 1), the service won't work. You must ask Swisscom to switch the activation to the correct OTO port number.

You can manage your device list, Wi-Fi password, and parental controls via the My Swisscom App or by calling 0800 800 800.