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Internet access over the FRITZ!Box is slow

The internet is slow? Is internet access very slow for devices connected to the FRITZ!Box? ✔ Here's what to do.

The internet connection on computers, smartphones, and other devices connected to the FRITZ!Box is very slow. As a result, web pages load slowly, it takes a long time to download files, and video streams are not played correctly or are interrupted, for example.

Important:If you are using your FRITZ!Box with an additional modem or router (for example a fiber optic modem) proceed as described in the guide Internet access over a different modem / router is slow.

Simply proceed as described below. After each measure, check whether the problem is solved.

Note:All instructions on configuration and settings given in this guide refer to the latest FRITZ!OS for the FRITZ!Box.

1 Checking the DSL line

Checking the speed of the DSL connection

Check whether the FRITZ!Box displays the DSL speed (data rate) guaranteed by your DSL provider:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "DSL Information" in the "Internet" menu.
  3. Click on the "DSL" tab.
  4. Check which throughput is displayed in the "Current throughput" line.
  5. If the current throughput is almost as high as the speed guaranteed by your DSL provider, there is no error.
    • If the current throughput is significantly lower, follow the steps in our guide DSL data rate is too low.

      Note:With many DSL lines, it is not possible to fully achieve the guaranteed throughput. That is why DSL providers say they offer DSL speeds "up to" a certain value.

Checking the DSL connection for errors

Problems with the DSL connection can slow down the internet connection. Therefore, check whether numerous errors occur on your DSL line:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "DSL Information" in the "Internet" menu.
  3. Click on the "DSL" tab.
  4. In the "Error Counter" section, check whether "Not Remediable Errors" (CRC) occur in the FRITZ!Box or the DSL exchange when the internet is used.
  5. If more than 500 errors occur within 15 minutes, follow the steps in our guide FRITZ!Box indicates numerous DSL connection errors.

2 Checking the speed of LAN connections

The following step is only necessary if your internet service provider guaranteed you speeds of over 100 Mbit/s:

  1. Click "Home Network" in the FRITZ!Box user interface.
  2. Click "Mesh" in the "Home Network" menu.
  3. In the "Mesh Overview", check the connection speed shown for the devices connected to the FRITZ!Box via network cable.
  4. If LAN connections are established with no more than 100 Mbit/s although the devices support gigabit LAN, follow the steps in our guide Transfer rate of LAN connections is only 100 Mbit/s.

3 Deactivating bandwidth reservation

The maximum throughput cannot be achieved on internet connections with speeds of 1 Gbit/s and more if bandwidth reservation is enabled for the home network:

  1. Click "Internet" in the FRITZ!Box user interface.
  2. Click "Filter" in the "Internet" menu.
  3. Click on the "Prioritization" tab.
  4. Disable the option "Reserve bandwidth for the home network".
  5. Click "Apply" to save the settings.

4 Optimizing Wi-Fi connections

The following step is only necessary if Wi-Fi connections to the FRITZ!Box or a Mesh Repeater are significantly lower than the Wi-Fi speed that can be achieved with the FRITZ!Box:

  1. Follow the steps in our guide Slow Wi-Fi connection.

5 Adjusting the Windows network settings

In order for a computer to access the internet, all web requests from the computer must be forwarded to the FRITZ!Box. If the computer automatically obtains its IP settings from the FRITZ!Box via DHCP, it also automatically receives a default gateway (IP address of the FRITZ!Box).

Configuring multiple default gateways is not allowed and causes errors. Therefore, make sure that only one single default gateway is configured on the computer:

Note:Note for network experts: Default gateways required for routing to another IP network can be replaced by a static route. Refer to the Windows help for information on setting up static routes.

  1. Press the keyboard shortcut Windows key + R.
  2. Enter cmd in the "Open" field and click "OK".
  3. Enter route print in the command prompt window and press Enter.
  4. If you see several entries in the table with 0.0.0.0, then there is more than one default gateway:

    Windows 11

    1. Click (Start) and then (Settings) in the Windows task bar.
    2. Click "Network & Internet" in the "Settings" menu.
    3. Click "Advanced network settings".
    4. Click "More network adapter options" in the section "Related settings".
    5. Right-click the network adapter that is not connected with the FRITZ!Box.
    6. Click "Properties".
    7. Select "Internet Protocol Version 4 (TCP/IPv4)".
    8. Click "Properties".
    9. If a default gateway was entered, remove it.
    10. Click "OK" to save the settings.

    Windows 10

    1. Click (Start) and then (Settings) in the Windows task bar.
    2. Click "Network & Internet" in the "Settings" menu.
    3. Click "Change adapter options" in the section "Advanced network settings".
    4. Click the arrow next to the (Change view) button in the menu bar and select "Details".
    5. Right-click the connection for a network adapter that is not connected to the FRITZ!Box. The name of the adapter is listed under "Device Name".
    6. Click "Properties".
    7. Select "Internet Protocol Version 4 (TCP/IPv4)".
    8. Click "Properties".
    9. If a default gateway was entered, remove it.
    10. Click "OK" to save the settings.
  5. Repeat these steps for all network adapters that are not connected to the FRITZ!Box.

6 Checking internet applications

VPN connections and applications that monitor or regulate internet access, such as firewalls, virus scanners, parental controls filters, or software that prioritizes individual internet applications, can reduce the speed of the internet connection.

  1. Clear any existing VPN connections and disable all other internet applications for testing purposes.
  2. Test the speed of the internet connection, for example download a large file.
  3. If the internet connection is fast enough now, configure the other applications so that they do not limit the speed of the internet connection. Refer to the manufacturer of the application for information on how to set it up, for example consult the manual.

Now the FRITZ!Box and the devices connected to it establish the fastest possible internet connection. If internet access continues to be too slow, your internet service provider may be throttling your internet connection or experiencing technical difficulties, or the internet services may be temporarily overloaded, or there may be a device error if only individual devices are affected. The internet service provider or the manufacturer of the devices in question may be able to give you advice on how to solve the problem.