Buffering has a short list of causes, and most are in the home, not at the provider. This checklist goes from the quickest and most likely fixes to the ones that mean calling support. It draws on the troubleshooting pages of Swisscom, Sunrise, Netflix and Zattoo (state: October 2026), and works for licensed services and apps alike.
01
Fix TV buffering: the first five minutes
Do these in order and test after each step:
- Check that all cables on the box, router and TV are firmly connected
- Restart the router and the TV box: unplug both for 10 seconds, then reconnect, as Swisscom instructs
- Select the correct HDMI input with the TV's own remote if there is no picture at all
- Restart other devices on the home network that may be using the line, such as a Wi-Fi box, powerline adapter or switch
- Open the provider's status page to rule out a fault on their side: Swisscom publishes faults and maintenance at swisscom.ch/status
02
Network cable or Wi-Fi
Wi-Fi is the most frequent cause. Sunrise says its TV Box can use Wi-Fi but recommends a cable connection because it is more stable, and Zattoo names a LAN cable as the most stable option, ideal for a TV; it lists distance from the router, walls and ceilings and other devices on the network as what disturbs Wi-Fi. If your TV is far from the router, a cable or a powerline adapter often fixes stutter that a faster internet plan would not.
03
Update and restart the app and the device
For the blue TV app Swisscom lists a set of checks that fit any streaming app: check the internet connection, switch the TV and box off and on, log out of the app and in again, restart the other devices in the network and update the software of the TV or box.
04
Lower the quality to test your line
Netflix advises that if your internet provider limits your speed, you can lower the video quality to get a more stable connection or to fix buffering. The same test works for any service: if SD plays smoothly and Full HD does not, the line or the Wi-Fi cannot carry the higher bitrate, and internet speed for TV streaming shows what each quality needs.
05
Phone, tablet and laptop: the minimums
On a laptop, Swisscom states that blue TV needs more than 4 GB of free RAM, Windows 10 or macOS 11 (Big Sur) or newer and the latest Chrome, Firefox, Safari or Edge. On a phone it asks for iOS 14 or Android 8 as a minimum. For both, the connection needs at least 0.5 Mbit/s and 5 Mbit/s for the best picture; close programmes you do not need on a laptop.
06
Symptom, likely cause and fix
A quick reference for what you see:
| Symptom | Likely cause | What to try |
|---|---|---|
| Stutter on every channel in the evening | Overloaded line or Wi-Fi | Cable instead of Wi-Fi; test at that time of day |
| One channel fails, others work | Problem at the channel or its stream | Check the provider's status page; try again later |
| Picture freezes after some minutes | Weak Wi-Fi signal or overheating device | Move closer or use a cable; restart the device |
| Lower quality plays, higher stutters | Not enough sustained speed | Compare with the figures per stream; ask the provider about the line |
| Black screen, sound present | App or device fault | Restart; update; log out and in |
07
When to call support
If a cable, a restart and a lower quality do not help, collect what you saw: the time, the channel, the device and whether other devices stutter too. A pattern across devices points to the line, a single device points to the device, and one channel points to the provider. For an unlicensed service there is usually nobody to call, which is one more reason to read IPTV scams and red flags before you pay.
08
Where to go next
See also Why live streams lag behind TV, IPTV glossary and Swisscom blue TV explained. For the whole picture, start from IPTV Switzerland: licensed providers compared.
Also useful: A second TV and Do you need a TV box?.
FAQ
Frequently asked questions
Why does my TV stream keep buffering?
Most often because of weak Wi-Fi, an overloaded line in the evening or a device that needs a restart or an update. A network cable and a restart fix the majority of cases.
Does a faster internet plan fix buffering?
Not always. Stutter is often caused by the Wi-Fi link to the TV, not by the plan, and a stable line matters more than a high peak speed.
Should I use Wi-Fi or a cable for TV?
A cable is more stable: Sunrise recommends one for its TV Box and Zattoo calls a LAN cable the most stable option. If a cable is impossible, move the router closer and keep other heavy users off the network.
How do I find out whether the fault is at the provider?
Check the provider's status page, such as swisscom.ch/status, and see whether one channel fails while others play.
Sources
Read next
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