---
title: "O2 (Telefónica Germany) slow internet in Germany: tests, evidence and complaints · Kilobat Guides"
url: "https://kilobat.app/guides/o2-homebox-slow-internet-complaint"
description: "O2 (Telefónica Germany) internet slow or dropping out in Germany? Check equipment, compare tests, keep evidence and follow the complaint route."
---

# O2 (Telefónica Germany) slow internet in Germany: tests, evidence and complaints

If your O2 (Telefónica Germany) connection is slow or unreliable, start with these equipment checks. Then document a repeatable result and ask for a specific investigation.

Applies to: O2 HomeBox 4 (7741), from O2’s manual and firmware-update guide (menus as of 2026). O2 warns that menu entries can change as the product develops. Older HomeBox 3 (6742) and 2 (6641) menus differ. Labels are in German, with an English gloss. · Checked: 3 November 2026

## When this helps

- You use O2 (Telefónica Germany) in Germany.
- Your connection is slower than expected, drops out or performs badly at certain times.

## Check your O2 HomeBox

These checks apply to O2 HomeBox. Check the model before following its menus.

1. Sign in at `http://o2.box`; the **Übersicht** (Overview) page opens.
2. Check **Internet** for the online status, connection time and public IP addresses.
3. Check **System** for the device name, firmware version and system time.
4. Click **Aktualisieren** (Refresh) to update the page.

## Separate the service from your home Wi-Fi

For the exact settings and supported equipment, see [the O2 HomeBox guide](https://kilobat.app/routers/o2-homebox).

Do not factory-reset the equipment as a first step. A reset can erase service settings and interrupt phone service.

1. Compare a wired connection to the router with Wi-Fi on the same device.
2. Repeat the same test server during the slowdown and at a quieter time.
3. Record download, upload, latency and whether another household device was using the connection.

## How to complain to O2 (Telefónica Germany)

Use [O2 (Telefónica Germany)’s official support](https://www.o2online.de/assets/blobs/pdfs/2249366/) to report the fault. Request a formal complaint reference if it remains unresolved.

Include the plan wording, dates, test conditions, previous references and the specific outcome you want. Ask for a written response.

For the local escalation route and conditions, follow [the Germany complaint guide](https://kilobat.app/guides/germany-slow-internet-speed-reduction).

## Collect the evidence with Kilobat

On a Mac, Kilobat can record connection checks and produce a support report. Review the report and add your test conditions before sharing.

The basic report export is free. [Kilobat Pro’s complaint wizard](https://kilobat.app/internet-complaint) helps assemble your evidence, impact and requested resolution into a draft you review and send.

Measurements cover this Mac while monitoring ran. They cannot prove whole-home uptime, establish provider fault or replace a required official measurement procedure.

## Sources

- [O2: Handbuch O2 HomeBox 4 (7741) (PDF)](https://www.o2online.de/assets/blobs/pdfs/2249366/)
- [O2: Anleitung zum manuellen Firmware-Update, O2 HomeBox 4 (7741) (PDF)](https://www.o2online.de/assets/blobs/pdfs/firmware-update-anleitung-o2-homebox-4-7741/)
- [O2: Router-Anleitungen und Handbücher zum Download](https://www.o2online.de/service/router/router-anleitungen/)
- [O2: Router-Hilfe – alle Tipps und Infos im Überblick](https://www.o2online.de/service/router/)
- [O2: O2 HomeBox 4 – Infos und Einrichtung](https://www.o2online.de/service/router/homebox-4/)

Checked on 3 November 2026.

## Related guides

- [Internet slower than advertised? Test it before you complain](https://kilobat.app/guides/internet-slower-than-advertised): A low speed test is a starting point.
- [Wi-Fi slow but Ethernet fast? Find the wireless bottleneck](https://kilobat.app/guides/wifi-slow-ethernet-fast): If the same device is consistently faster on Ethernet, investigate the wireless path first.
- [Slow internet complaint letter: a template with the evidence to attach](https://kilobat.app/guides/broadband-complaint-letter): A useful complaint says what happened, how you tested it and what you want the provider to do next.