Zapret was originally developed as a response to the growing use of DPI technologies by governments and ISPs to monitor, filter, or censor internet traffic. Instead of relying on external servers like VPNs or proxies, Zapret takes a smarter approach it manipulates packets locally on the user’s device, making it difficult for censorship systems to detect blocked domains while keeping browsing fast and lightweight.

Key Features

How Zapret Works

Understanding Deep Packet Inspection (DPI)

Deep Packet Inspection (DPI) is a technology used by internet service providers, governments, or networks to analyze internet traffic beyond just the basic headers. Instead of simply examining where a packet is going (like in typical routing), DPI can look inside the packet’s data and identify patterns such as:

• Domain names in the HTTP header (Host: field).
• Keywords within the traffic.
• Application signatures (e.g., torrents, VPNs, or VoIP).

This allows firewalls to block, throttle, or redirect connections to specific websites or services.

Techniques Used by Zapret

Zapret confuses censorship systems by making small, innocuous changes to network packets, which:

• Do not affect how websites see your traffic.
• Disrupt the ability of DPI systems to accurately identify blocked content.

TCP/IP Packet Modification

DPI engines often expect packets in a very specific format. Zapret makes minor modifications, such as:

• Changing the case of characters (Host: → hOst:).
• Reordering harmless headers.
• Adding extra spaces or line breaks.

These minor changes render the packet ineffective for DPI detection, but it remains perfectly valid for the actual web server.

Fake Packet Injection

Zaproxy can send fake or misleading packets that appear legitimate to the firewall.

• For example, it can send an extra header that tricks the DPI (Deep Packet Inspection) into thinking the request is going somewhere else.
• The firewall gets confused and allows the traffic to pass through.

Meanwhile, the actual website receives the correct packet and responds normally.

TTL (Time To Live) Manipulation

Every packet on the internet has a TTL value (the number of hops it can traverse before being discarded).

• Zapret sets a very low TTL value for the disguised packets, causing them to expire before they reach the actual server.
• DPI systems located near the user see and analyze these packets, but the real server never receives them.
• As a result, the firewall is “fooled” into processing the fake data instead of the actual connection.

Why These Techniques Work

Censorship firewalls, while powerful, are inflexible. They rely on rigid rules to identify prohibited traffic.

• If the data doesn’t exactly match the expected pattern, they often fail to block it.
• Zapret takes advantage of these rigid expectations by slightly modifying the packets in a way that is harmless to the destination server but confusing to the DPI engine.

As a Result:

• You can access blocked websites.
• Your ISP’s censorship system is bypassed.
• Browsing speed remains faster than with a VPN because the traffic is not rerouted.

Platforms Supported

Installation Guide

Where to download Zapret

• Official builds of Zapret are available on its GitHub repository or trusted mirrors such as zapret.io.
• To avoid security risks, make sure you download the latest stable version from an official source.
• After downloading, extract the zip file to a folder on your computer.

System Requirements

• Operating System: Windows 7, 8, 8.1, 10, or 11 (64-bit recommended).
• Permissions: Administrator privileges are required (because it modifies network packets).
• Network: Works with wired, Wi-Fi, or mobile hotspot connections.
• Dependencies: No external libraries are required (self-contained executable).

Step-by-Step Installation on Windows

• Download the latest release ZIP file from zapret.io or GitHub.
• Extract the ZIP archive to a convenient folder (e.g., C:\zapret).

Open Command Prompt as Administrator:

• Press Win + S, type cmd, right-click and select Run as Administrator.

Navigate to the extracted folder:

• cd C:\zapret

Run the program with a preset. For example:

• zapret.exe -1

FAQs About Zapret