The file hosts is a fundamental element of the network configuration in operating systems, including the mobile platform Android. This small text document serves as a local database that matches domain names with specific IP addresses before the request goes out onto the global network. Users often resort to editing it to block intrusive advertising, prevent access to malicious resources, or bypass geographic restrictions without using third-party VPN services.
However, the process of editing this file on mobile devices is associated with certain technical difficulties. Unlike desktop operating systems, the architecture Android default limits direct access to system partitions for security purposes. This means that it will not be possible to make edits to the file using standard methods available to the average user. You will need to either obtain extended privileges or use specialized tools that simulate the operation of a system file at the application level. /system/etc/hosts it won't work. You will need to either gain elevated privileges or use specialized tools that simulate the operation of a system file at the application level.
In this article we will analyze in detail all the available methods for editing the network configuration. We will consider both radical ways to obtain root accessand safer alternatives that do not require intervention in the system. You will learn which tools to use, how to correctly syntax entries, and what risks an incorrect configuration of your smartphone's firewall carries.
The principle of operation and purpose of the hosts file
The name resolution mechanism on the network works according to a strict hierarchy. When you enter a website address in a browser, the operating system first accesses the local file hosts. If a corresponding entry is found in it, the system immediately redirects traffic to the specified IP address, ignoring requests to the provider's DNS servers. This allows you to instantly block unwanted domains by redirecting them to a local address 127.0.0.1 (localhost), which actually leads to nowhere.
Using this method has a number of undeniable advantages over installing ad blockers in the form of separate applications. Firstly, filtering occurs at the system level, which means advertising is blocked not only in the browser, but also inside many mobile games and utilities. Secondly, it reduces the load on the processor and RAM, since it does not require running background services to analyze traffic in real time.
However, it is worth understanding the limitations of this approach. The file hosts cannot analyze the content of web pages or cut out individual advertising blocks while preserving the rest of the content. It works on an all-or-nothing basis: either the entire domain is blocked or it is allowed to pass completely. For complex cases where advertising is placed on the same domain as useful content, this method may be useless or even harmful.
Before making any changes, always create a backup copy of the original file. This will allow you to instantly restore Internet functionality in case of an error.
Preparation of the device and necessary tools
Before you start editing system files, you need to select the appropriate tool. The market offers many solutions, from simple text editors to powerful system management combines. The choice of a specific application depends on whether your device has root access. Without them, your options will be significantly limited, and you will have to rely on methods that work through a local VPN tunnel.
If you plan to work with the system partition directly, you will need a file manager that supports superuser rights. Popular solutions such as Root Explorer or Solid Explorerprovide a convenient interface for navigating hidden directories. Also make sure that USB debugging is enabled on the device if you plan to use a computer to transfer the corrected file.
- 📱 File manager with Root access: Required for direct editing of files in the directory
/system/etc/. - 📝 Text editor: Any application that supports UTF-8 encoding without BOM to avoid problems with reading the file system.
- 🌐 Current list of domains: a pre-prepared list of addresses to block, so as not to search for them during the editing process.
It is important to note that some smartphone manufacturers, such as Xiaomi or Huaweimay have additional levels of protection for the bootloader or system partitions. Even if you have root access, the system may prohibit writing to certain areas of memory. In such cases, you may need to unlock the bootloader or use specific scripts.
Method 1: Direct editing with root access
This method is the most effective and reliable, since changes are applied globally to the entire operating system. First, you need to make sure that superuser rights are activated on your device. If you have not received them yet, you will need to unlock the bootloader and install a specialized utility, for example Magisk. Please note that this procedure may void the device's warranty.
After obtaining access rights, open your file manager and activate root mode. This is usually done through the app settings or a special button in the interface. Follow the path /system/etc/. Here you will find a file named hosts. Before editing, copy it to a safe place, for example, in the internal memory in a folder Download, under the name hosts.backup.
Open the original file for editing. You will see a list of IP addresses and domain names. A standard blocking entry looks like this:
127.0.0.1 adserver.example.comAdd new lines to the end of the file, following the format: first the IP address, then a space or tab, and then the domain name. Do not use comments or extra characters unless you are sure of their syntax. After making all changes, save the file. The system may ask for confirmation to overwrite the system file - agree.
☑️ Checklist before saving
⚠️ Warning: Never delete the source lines in the hosts file, especially the entry
127.0.0.1 localhost. Removing this line may lead to unstable operation of network services and failure of some applications.
Method 2: Using applications without Root access
For users who do not want or cannot obtain superuser rights, there are alternative solutions. Applications like AdAway (in non-root mode) or Blokada create a local VPN tunnel on the device. All network traffic passes through this application, which filters requests based on its own block list, emulating the behavior of the hosts file.
The main advantage of this approach is security and ease of installation. You do not need to tamper with system files, which eliminates the risk of “bricking” the device. Installation is carried out directly from the application store Google Play or through the official website of the developer. Once launched, the application will ask for permission to create a VPN connection, which must be confirmed.
However, this method has its drawbacks. Because a virtual network interface is used, some applications may conflict with it or may not work. In addition, constant use of a VPN filter may slightly increase battery consumption. However, for most ad blocking tasks, this method is quite sufficient.
Why do some applications not work with a local VPN?
Some highly secure banking applications and services consider any VPN connection a potential security threat and block their work when it is detected. In such cases, you have to temporarily disable the blocker.
Method 3: Editing via computer and ADB
If editing a file directly on your smartphone seems inconvenient or risky to you, you can use a computer. To do this, you will need to install the package ADB (Android Debug Bridge) on your PC and enable USB debugging on your phone. This method allows you to replace the hosts file using the power of a desktop text editor.
First, connect your smartphone to the computer with a cable and open the command line or terminal on the PC. Make sure that the device is visible in the system by entering the command adb devices. Next, you need to obtain rights to remount the system partition in write mode. Execute the following sequence of commands:
adb shellsu
mount -o remount,rw /system
After this, you can pull the file onto your computer, edit it and download it back. Use commands adb pull /system/etc/hosts C:/hosts to copy and adb push C:/hosts_new /system/etc/hosts to download the modified version. After completing the work, do not forget to remount the partition back to read-only mode with the command mount -o remount,ro /system.
| ADB command | Description of action | Required rights |
|---|---|---|
adb pull |
Copying a file from the device to the PC | Debugging USB |
adb shell su |
Obtaining superuser rights in the shell | Root access |
mount -o remount,rw |
Allowing writing to the system partition | Root access |
adb push |
Downloading a modified file to the device | Root access |
This method is especially convenient when you need to make bulk changes or use complex scripts to generate a blocking list. Working with a physical keyboard and a large monitor reduces the likelihood of typos, which are critical when editing system configs.
The method using ADB is ideal for advanced users, as it combines the convenience of working on a PC with the depth of access to the smartphone system.
File structure and syntax rules
Correct file formatting hosts is critical for its correct operation by the operating system. Each line of the file represents a separate directive. Empty lines and lines starting with a hash character #are ignored by the interpreter and used for comments. This allows you to add explanations to your entries without breaking functionality.
The basic structure of an entry consists of two required elements: an IP address and a domain name. The separator between them is one or more spaces or a tab character. Using other delimiters, such as commas or semicolons, will result in the system not being able to recognize the command and blocking will not work.
Consider an example of correct and incorrect filling:
- ✅ True:
127.0.0.1 doubleclick.net—the system will redirect the request to the local host. - ❌ Incorrect:
127.0.0.1,doubleclick.net— the comma is invalid, the entry will be ignored. - ❌ Incorrect:
block doubleclick.net—no IP address, syntax error.
It is also worth mentioning the file encoding. The hosts file must be saved in the format UTF-8 without the BOM (Byte Order Mark) mark. The presence of a BOM may result in the first line of the file not being read correctly, since the system will perceive the service bytes as part of the text. Most advanced text editors allow you to select this option when saving.
⚠️ Attention: Avoid using Cyrillic characters in domain names inside the hosts file. Record the domain in its punycode representation (as
xn--...), if such a need arises, although for most tasks this is not required.
Possible problems and solutions
After making changes, users often encounter a situation where the blocking does not take effect immediately. This is due to the fact that the operating system Android caches DNS queries to speed up the network. Old entries may remain in memory for some time, ignoring your new rules in the hosts file.
The easiest way to force a DNS cache refresh is to reboot the device. This is guaranteed to clear all network buffers and force the system to re-read configuration files from disk. If rebooting is not possible, you can try switching airplane mode: turn it on for 10 seconds and then turn it off. This will reconnect the network interfaces and often helps clear the cache.
Another common problem is a conflict with DNS-over-HTTPS (DoH) or DNS-over-TLS (DoT) in modern versions of Android. These technologies encrypt DNS queries and can bypass the local hosts file by sending queries directly to protected servers. For the hosts file to work correctly, you need to disable the “Private DNS” function in the network settings.
Go to Settings → Connections → Other connection settings → Private DNS and select mode Disabled or Auto. If a specific provider is selected (for example dns.google), the system hosts table will be ignored in favor of the remote server. This is an important detail that is often forgotten when setting up blocking.
What to do if it disappears after editing Internet?
If you make a syntax error or block a critical system domain, the Internet may stop working. Restore the file from the backup (hosts.backup) you created before starting work, or reset the network settings in the phone menu.
Security and legal aspects
Using the hosts file to block ads is legal in many jurisdictions, as the user has full control over the traffic passing through his personal device. However, you should be careful when using ready-made block lists from unverified sources. Attackers can insert entries into such lists that redirect traffic from popular services to phishing sites.
Always check the source of the domain list before importing it. Official repositories of open source projects, such as StevenBlack/hosts on GitHub, are considered reliable and are regularly audited by the community. Avoid downloading files from dubious forums or telegram channels, where no one guarantees the purity of the data.
In addition, remember that modifying system files may violate the terms of service of some applications. Although ad blocking itself rarely results in account suspension, using bypass methods may be considered by developers as a violation of the license agreement. Use these tools wisely and only for personal needs.
Is it possible to edit the hosts file on Android without root access?
Directly changing the system file /system/etc/hosts without superuser rights is impossible due to security restrictions of the Linux kernel. However, you can achieve a similar effect by using applications that create a local VPN tunnel (for example, Blokada or AdGuard), which filter traffic on the fly without requiring access to the system partition.
Where exactly is the hosts file located on a smartphone?
Physical path to the file in the Android file system: /system/etc/hosts. To access this directory, you need a file manager with support for Root access or using the ADB command line with superuser privileges.
Why did the advertisement not disappear after editing the file?
The most likely reason is the active “Private DNS” function in the Android settings, which encrypts requests and bypasses the local file. It is also possible that the DNS cache has failed. Try disabling Private DNS and rebooting the device.
Is it safe to download ready-made hosts lists from the Internet?
It is only safe if you trust the source. It is recommended to use trusted open repositories (for example, the StevenBlack project). Downloading lists from unknown sites carries the risk of redirecting traffic to malicious servers.
How to roll back changes if the phone has stopped connecting to the network?
You need to restore the original hosts file. If you have a backup copy (for example, hosts.backup), rename it back to hosts via a file manager with root access. If there is no access to the file, resetting the network settings or completely resetting the device to factory settings (Hard Reset) will help.