b16

.b16BitTorrent Blocklist

BitTorrent · 2005

Developer
BitTorrent
Category
System Files
MIME Type
application/octet-stream
First Released
2005
Open Format
Yes
File Signature
N/A (Plain text file)
At a Glance
.b16
BitTorrent Blocklist

.b16 files are plain text lists of IP addresses used by BitTorrent clients to block known malicious or unreliable trackers and peers for security.

Reviewed on July 23, 2026
Compression
Plain text
Transparency
Yes
Editability
High
Best for
IP blocking

Key Features

  • Plain text format for easy readability and editing.
  • Stores lists of IP addresses to block.
  • Enhances BitTorrent client security and stability.
  • Supports individual IP addresses and ranges.

Best For

  • BitTorrent users seeking enhanced security.
  • Maintaining a custom list of untrusted IP addresses.
  • Quickly updating a blocklist for a BitTorrent client.

Less Ideal For

  • Storing general network data.
  • Configuring complex network settings.
  • Distributing executable software.
  • Holding any data other than IP address lists.

Common Use Cases

  • Blocking known malicious IP addresses in BitTorrent clients.
  • Preventing connections to unreliable or scam trackers.
  • Improving download speeds by avoiding problematic peers.
  • Manual management of a custom blocklist.

How to Open It

  1. Open the .b16 file with any text editor like Notepad (Windows), TextEdit (macOS), or nano/vim (Linux).
  2. Most BitTorrent clients, such as qBittorrent, uTorrent, or Transmission, automatically detect and use these files if placed in the correct directory.
  3. Check your specific BitTorrent client's documentation for instructions on how to configure and manage IP blocklists.

What is a .b16 file?

A .b16 file is a plain text file used by the BitTorrent client to store a list of IP addresses that are known to be malicious or unreliable. This list, often referred to as a 'blocklist' or 'tracker blocklist', helps to prevent your BitTorrent client from connecting to potentially harmful servers or peers. By maintaining this list, users can enhance their security and improve the overall stability of their BitTorrent downloads. The format is simple and human-readable, making it easy to manage and update manually if needed.

Programs That Open .b16 Files

PlatformProgram
WindowsNotepadFreeOfficial
qBittorrentFree
uTorrentPaid
macOSTextEditFreeOfficial
TransmissionFree
LinuxnanoFreeOfficial
vimFreeOfficial
qBittorrentFree

Common Problems with .b16 Files

⚠️ BitTorrent client not using the blocklist.
Ensure the .b16 file is placed in the correct directory specified by your BitTorrent client's settings and that the client is configured to use IP filtering. Restart the client after placing the file.
⚠️ Blocklist is outdated or missing entries.
Download updated blocklists from reputable sources or manually add/remove IP addresses. Ensure the IP addresses are correctly formatted (e.g., IPv4 or CIDR notation).

Frequently Asked Questions

What is a BitTorrent IP blocklist?

It's a list of IP addresses that your BitTorrent client will refuse to connect to. This helps prevent connections to known malicious servers, copyright trolls, or unreliable peers.

Can I create my own .b16 file?

Yes, you can create a plain text file with a .b16 extension and manually add IP addresses, one per line, or ranges in CIDR notation.

Where do I put the .b16 file?

The location varies by client. Commonly, it's in the client's main configuration folder or a specific 'blocklists' subdirectory. Refer to your client's documentation.

Technical Details

The .b16 format is essentially a plain text file where each line typically contains a single IP address or an IP address range. These entries are used by BitTorrent clients to filter out connections to problematic peers or trackers. The file is not a complex binary structure; it's designed for easy parsing and manual editing.

Did You Know?

While .b16 is a common extension for BitTorrent blocklists, some clients might use .dat, .gz, or simply .txt.
The '16' in .b16 doesn't have an official meaning but is likely an internal identifier used by early BitTorrent software.

Security Information

Opening a .b16 file itself with a text editor is safe, as it's just plain text. However, the effectiveness of the blocklist depends on the source. Only use blocklists from trusted sources to avoid accidentally blocking legitimate peers or trackers.

Related Extensions