mikrotik-adlist-builder/README.md

Mikrotik Adlist Builder

mikrotik-adlist-builder is a small Python tool for building MikroTik adlists used to block ads and harmful domains.

It can download multiple blocklists from remote URLs, read local files, extract valid domain names from different formats, merge them, remove duplicates, and write the final output in a MikroTik-friendly format:

0.0.0.0 example.com
0.0.0.0 ads.example.net

Features

• Supports multiple input sources
• Downloads blocklists from http:// and https:// URLs
• Reads local files from:
  • relative paths such as ./custom-domains.txt
  • absolute paths
  • file:// URLs
• Supports multiple common blocklist formats:
  • ABP-style rules such as ||example.com^
  • hosts file syntax such as 0.0.0.0 example.com
  • plain domain lists such as example.com
• Removes duplicates automatically
• Filters out invalid entries
• Writes a merged output file ready for MikroTik adlist import

Requirements

• Python 3.9 or newer

Installation

No external dependencies are required.

Clone the repository or just save the script locally:

chmod +x mikrotik-adlist-builder.py

You can then run it directly:

./mikrotik-adlist-builder.py

Or with Python:

python3 mikrotik-adlist-builder.py

Default sources

The script includes a built-in DEFAULT_URLS list. Example:

DEFAULT_URLS = [
    "https://big.oisd.nl/",
    "https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts",
    "./custom-domains.txt",
]

This means the tool can combine public online blocklists with your own local domain list.

Usage

Use default sources

python3 mikrotik-adlist-builder.py

This will create:

adlist.txt

Specify custom URLs

python3 mikrotik-adlist-builder.py \
  -u https://big.oisd.nl/ \
  -u https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts

Mix remote and local sources

python3 mikrotik-adlist-builder.py \
  -u https://big.oisd.nl/ \
  -u ./custom-domains.txt \
  -u ./my-extra-list.txt

Use a local file via file://

python3 mikrotik-adlist-builder.py \
  -u file:///home/user/blocklists/custom.txt

Change output file

python3 mikrotik-adlist-builder.py \
  -o mikrotik-adlist.txt

Full example

python3 mikrotik-adlist-builder.py \
  -u https://big.oisd.nl/ \
  -u https://raw.githubusercontent.com/StevenBlack/hosts/master/hosts \
  -u ./custom-domains.txt \
  -o mikrotik-adlist.txt

Supported input formats

1. ABP syntax

Example:

||example.com^
||ads.example.net^

Some simplified variants are also accepted, for example:

||example.com

2. Hosts syntax

Example:

0.0.0.0 example.com
127.0.0.1 ads.example.net

3. Plain domain syntax

Example:

example.com
ads.example.net
tracker.example.org

Local custom domain file example

Example custom-domains.txt:

example-bad-site.com
ads.example.net
tracker.example.org

You can also mix in hosts-style entries:

0.0.0.0 bad.example.com
127.0.0.1 ads.badsite.net

And ABP-style rules:

||tracker.example.org^
||ads.example.net^

Output format

The generated file contains one domain per line in this format:

0.0.0.0 domain.tld

Example:

0.0.0.0 ads.example.com
0.0.0.0 tracker.example.net
0.0.0.0 malware.example.org

Import into MikroTik

The resulting file is intended to be used as a source for a MikroTik adlist or for further processing before import, depending on your RouterOS version and setup.

Notes

• Relative local paths are resolved against the current working directory from which you run the script.
• file:// paths should normally be absolute.
• Duplicate domains are removed automatically.
• Invalid lines, comments, whitelist rules, localhost-style entries, IPv6 entries, and malformed domains are ignored.

Example output messages

[INFO] Downloading: https://big.oisd.nl/
[INFO] Domains found: 123456
[INFO] Downloading: ./custom-domains.txt
[INFO] Domains found: 25
[OK] Output written to: adlist.txt
[OK] Total unique domains: 123470

License

Use, modify, and distribute freely as needed.