Zapret vs GoodbyeDPI vs ByeDPI — DPI Bypass Tools Compared 2026
YouTube blocked. Discord throttled. VPN connections reset before they even handshake. In 2026, DPI-based censorship is more aggressive than ever, and three open-source tools have emerged as the primary weapons against it: GoodbyeDPI, ByeDPI, and Zapret. Each takes a fundamentally different approach to packet-level DPI evasion. This guide breaks down how they work, what they can and cannot bypass, and which one you should use based on your platform, threat model, and technical skill level.
Why DPI Bypass Matters More Than Ever
State-level internet censorship has escalated dramatically. Russia's TSPU (Technical Means of Countering Threats) boxes, deployed directly at ISP infrastructure, now perform deep packet inspection on all traffic in real time. YouTube has been throttled or blocked entirely on many Russian ISPs. Discord, Signal, and dozens of other services face similar restrictions across multiple countries. Iran, Turkmenistan, and China continue to tighten their filtering infrastructure.
VPNs are an obvious solution, but DPI systems have gotten remarkably good at detecting and blocking VPN protocols. WireGuard, OpenVPN, and even many "stealth" VPN implementations are fingerprinted and dropped at the network edge. This is where DPI bypass tools come in — they don't encrypt or tunnel your traffic through a remote server. Instead, they manipulate outgoing packets at the OS level to exploit weaknesses in DPI parsing logic. No server needed, no subscription, no trust in a third party.
Three tools dominate this space: GoodbyeDPI by ValdikSS, the original and most widely known; ByeDPI, which brought DPI bypass to Android without root; and Zapretby bol-van, the most technically powerful option with support for Linux, OpenWrt routers, and advanced QUIC desynchronization. Let's compare them in depth.
GoodbyeDPI — The Original DPI Bypass Tool
GoodbyeDPI, created by ValdikSS, is the tool that started the modern DPI bypass movement. Released in 2017, it remains the most popular DPI evasion utility with over 25,000 GitHub stars. It runs exclusively on Windows, using the WinDivert driver to intercept and modify outgoing packets before they leave the network stack.
GoodbyeDPI implements 7 active bypass methods and 2 passive ones. The active methods manipulate packets in transit, while the passive methods adjust system-level TCP behavior to make connections less identifiable to DPI.
// GoodbyeDPI core techniques:
- 1. TCP segmentation — split the first data packet (ClientHello) into small segments
- 2. Fake packets with wrong checksum — inject packets DPI processes but the server drops
- 3. Fake packets with wrong TTL — reach the DPI box but expire before the server
- 4. Fake packets with wrong SEQ/ACK — desync DPI state tracking
- 5. HTTP Host header space — add a space after "Host:" to break naive parsers
- 6. HTTP Host header case change — "hoSt:" instead of "Host:"
- 7. HTTP header fragmentation — split the Host header across TCP segments
- P1. TCP window size reduction (passive) — force smaller initial segments
- P2. MSS adjustment (passive) — limit maximum segment size at the TCP level
The typical GoodbyeDPI command for bypassing YouTube blocking in 2026 uses a combination of these strategies. Here are the most commonly effective parameter sets:
# GoodbyeDPI — recommended settings for YouTube (2026)
goodbyedpi.exe -5 --set-ttl 5 --dns-addr 77.88.8.8 --dns-port 1253
# Alternative with explicit fake packet + segmentation
goodbyedpi.exe -9 --fake-from-hex 160301FFFFFFFFFFFFFFFFFFFFFFFF --set-ttl 3 -e 1
# Preset modes (-1 through -9) combine different techniques:
-1 = segment + header space + no host
-5 = -1 + fake packet with wrong checksum + TTL manipulation
-9 = most aggressive mode — all techniques combined
Strengths:GoodbyeDPI is easy to use. Download the binary, run a preset command, and it works. The presets (-1 through -9) abstract away the complexity. The community is large, documentation is excellent, and new bypass strategies are shared quickly on forums and Telegram channels. For Windows users facing basic-to-moderate DPI, it's the fastest path to unblocked access.
Weaknesses:Windows only — no Linux, no macOS, no routers. GoodbyeDPI has no QUIC/UDP bypass support, which is increasingly a problem as more services move to HTTP/3. Against advanced TSPU systems that perform full TCP stream reassembly, GoodbyeDPI's segmentation tricks are less reliable. The tool can't apply different strategies per-host — it's all or nothing for all connections.
ByeDPI — Mobile DPI Bypass
ByeDPI fills the critical gap that GoodbyeDPI leaves: Android. Created as a userspace DPI bypass tool, ByeDPI creates a local SOCKS4/SOCKS5 proxy or a local VPN interface on Android devices to intercept and modify outgoing connections. The Android app (ByeDPIAndroid) requires no root access — it uses Android's VpnService API to capture traffic, applies desync techniques, and forwards the modified packets.
ByeDPI's desynchronization engine supports several techniques: TCP segmentation (splitting the ClientHello), fake packet injection with configurable TTL, disorder mode (sending TCP segments out of sequence), and OOB (out-of-band) data injection. The core binary is written in C and is extremely lightweight — under 200KB compiled.
// ByeDPI desync techniques:
- $ split — fragment ClientHello at a specified byte offset
- $ disorder — send TCP segments out of order (second before first)
- $ fake — inject a fake ClientHello with wrong data before the real one
- $ OOB — send out-of-band data to confuse DPI state machines
- $ TTL-based fake — set low TTL on fake packets so only DPI sees them
- $ TLS record fragmentation — split at the TLS record layer, not just TCP
# ByeDPI CLI — common desync parameters
ciadpi --disorder 3 --fake -1 --ttl 8
ciadpi --split 2 --disorder 3 --oob 1 --ttl 5
# On Android, these are configured via the UI — no CLI needed
Strengths:ByeDPI is the only viable option for Android users who don't want to root their device. The app is lightweight, has a simple toggle interface, and works surprisingly well against moderate DPI. An iOS variant called ByeByeDPI is also available for Apple devices. The small binary size and minimal resource usage make it ideal for mobile.
Weaknesses:ByeDPI's technique set is narrower than Zapret's. It has limited QUIC support and cannot apply multiple desync strategies per connection in the way Zapret can. Configuration requires understanding desync parameters — there are no simple presets like GoodbyeDPI's -1 through -9 modes. Against TSPU with full stream reassembly, effectiveness varies significantly by ISP.
Zapret — The Powerhouse
Zapret, created by bol-van, is the most technically advanced DPI bypass tool available. Originally built for Linux, it now supports FreeBSD, OpenWrt, Windows (via WinDivert), and even macOS. On Linux, Zapret uses nfqueue (netfilter queue) to intercept packets at the kernel's netfilter layer, modify them in userspace, and reinject them. This gives it extremely fine-grained control over packet manipulation — including full QUIC/UDP desynchronization, which neither GoodbyeDPI nor ByeDPI support properly.
Zapret's primary binary is nfqws (netfilter queue worker), which handles the actual packet manipulation. On Windows, it uses winws with WinDivert instead. The tool supports an extensive set of desync strategies that can be combined in a single command and applied conditionally based on protocol, hostname, or connection state.
// Zapret (nfqws) desync techniques:
- $ fake — send a fake ClientHello/first packet before the real one
- $ rst, rstack — inject fake RST/RST+ACK to reset DPI state
- $ hopbyhop — add IPv6 hop-by-hop extension header to confuse DPI
- $ destopt — add IPv6 destination options header
- $ ipfrag2 — IP fragmentation of the first outgoing data packet
- $ disorder — send segments out of order with retransmission
- $ split — TCP segmentation at configurable offsets
- $ tlsrec — TLS record layer fragmentation
- $ UDP desync — fake/hopbyhop/destopt/ipfrag for QUIC traffic
- $ Multi-strategy — chain multiple desync methods per connection
The real power of Zapret lies in its ability to chain multiple desync strategies and apply them conditionally. A single nfqws instance can apply different bypass techniques for different hosts, automatically detect which strategy works, and fall back to alternatives. Here are example commands for common scenarios:
# Zapret — bypass YouTube HTTPS blocking (Linux, nfqws)
nfqws --dpi-desync=fake,split2 --dpi-desync-split-seqovl=1 \
--dpi-desync-split-pos=1 --dpi-desync-fooling=md5sig,badseq \
--dpi-desync-fake-tls=/opt/zapret/files/fake/tls_clienthello_www_google_com.bin \
--dpi-desync-ttl=5 --filter-tcp=443
# Zapret — QUIC/UDP desync for YouTube (blocks QUIC throttling)
nfqws --dpi-desync=fake --dpi-desync-repeats=6 \
--dpi-desync-fake-quic=/opt/zapret/files/fake/quic_initial_www_google_com.bin \
--dpi-desync-ttl=4 --filter-udp=443
# Zapret on OpenWrt — network-wide bypass via iptables + nfqws
iptables -t mangle -I POSTROUTING -p tcp --dport 443 -j NFQUEUE --queue-num 200
nfqws --qnum=200 --dpi-desync=fake,disorder2 \
--dpi-desync-ttl=6 --dpi-desync-fooling=md5sig
# Zapret on Windows (winws)
winws.exe --wf-tcp=443 --dpi-desync=fake,split2 \
--dpi-desync-split-pos=1 --dpi-desync-ttl=5 --dpi-desync-fooling=md5sig
Strengths:Zapret is the most powerful DPI bypass tool in this comparison by a significant margin. It supports QUIC/UDP desync — critical for YouTube, which increasingly uses HTTP/3. It runs on OpenWrt routers, enabling network-wide bypass for every device without per-device configuration. The multi-strategy chaining and per-host filtering mean you can tune the bypass precisely. It's actively maintained by bol-van with frequent updates to counter new TSPU firmware versions. The autohostlist feature can automatically detect blocked domains and apply bypass only where needed.
Weaknesses:Zapret has a steep learning curve. There are no GUI presets — you need to understand desync methods, TTL values, split positions, and fooling strategies to build an effective command line. The documentation, while thorough, is primarily in Russian. Installing on OpenWrt requires comfort with command-line package management and iptables/nftables configuration. For non-technical users, the initial setup can be daunting compared to GoodbyeDPI's one-click presets.
Head-to-Head: Zapret vs GoodbyeDPI vs ByeDPI
| Feature | GoodbyeDPI | ByeDPI | Zapret |
|---|---|---|---|
| Creator | ValdikSS | hufrea | bol-van |
| Language | C | C | C |
| License | Apache 2.0 | MIT | MIT |
| Platforms | Windows | Android, Linux, Windows | Linux, Windows, macOS, FreeBSD, OpenWrt |
| Packet Driver | WinDivert | VpnService / raw sockets | nfqueue (Linux), WinDivert (Win) |
| Techniques Count | 7 active + 2 passive | 6 | 12+ |
| QUIC/UDP Support | No | Limited | Yes (full desync) |
| TSPU Effectiveness | Moderate | Moderate | High |
| Ease of Setup | Easy (presets) | Easy (mobile app) | Complex (CLI) |
| Router Support | No | No | Yes (OpenWrt, Keenetic) |
| Per-Host Rules | No | No | Yes (hostlist/autohostlist) |
| Active Development | Moderate | Active | Very active |
| GitHub Stars | 25K+ | 3K+ | 8K+ |
When to Use Which Tool
The right DPI bypass tool depends on your platform, technical comfort, and the sophistication of the censorship you're facing. Here's a practical decision guide:
GoodbyeDPI
Casual Windows User
Download the latest release, run a preset (-5 or -9), and you're done. No command-line knowledge needed. Best for unblocking YouTube or Discord on a Windows PC with moderate ISP-level DPI.
ByeDPI (ByeDPIAndroid)
Android Phone
Install the app from GitHub releases, toggle it on. No root required. Works via Android's VPN API. Also check ByeByeDPI for iOS. Ideal for mobile users who need quick bypass without a separate VPN service.
Zapret (nfqws)
Linux Desktop
Install from GitHub, configure nfqws with your ISP's effective parameters. Zapret's install_easy.sh script simplifies initial setup. Best for users comfortable with the terminal who want maximum bypass effectiveness.
Zapret on OpenWrt
Whole Network / Router
Deploy Zapret on your OpenWrt router and every device on your network gets DPI bypass automatically — phones, tablets, smart TVs, game consoles. The only tool that supports this use case.
Zapret (multi-strategy)
Advanced TSPU Bypass
For ISPs with aggressive TSPU firmware, Zapret's multi-strategy chaining (fake + split + disorder) with per-host autohostlist gives the highest success rate. Combine with QUIC desync for YouTube.
NetVeil by BypassCore
Research / Red Team
When packet-level tricks aren't enough — against full TCP reassembly + statistical analysis — NetVeil's protocol transformation, TLS fingerprint spoofing, and traffic analysis resistance go beyond DPI bypass into full traffic obfuscation.
What About NetVeil?
Zapret, GoodbyeDPI, and ByeDPI all operate at the same conceptual level: they manipulate packets to confuse DPI parsers. This works well against DPI systems that rely on signature matching and partial stream parsing. But it fundamentally cannot defeat DPI that performs full TCP stream reassembly or statistical traffic analysis — the traffic is still standard TLS to the real destination, just fragmented differently.
NetVeil, built by BypassCore, operates at a different layer entirely. Instead of tricking the DPI parser, it transforms the traffic so it genuinely looks like something else. Pluggable transports wrap your connections in protocols that DPI has no reason to block — real-looking HTTPS sessions with spoofed JA3/JA4 TLS fingerprints, HTTP/2 multiplexed streams with synthetic browsing patterns, or QUIC tunnels indistinguishable from Cloudflare CDN traffic.
NetVeil requires a relay server and is more complex to deploy than local packet manipulation tools. It's designed for researchers, red teamers, and organizations that need to bypass advanced censorship infrastructure — not as a quick YouTube unblocker. If Zapret or GoodbyeDPI work for your use case, use them. If they don't, NetVeil is the next step up.
The Future of DPI Bypass
The DPI bypass landscape is shifting rapidly. Several developments will reshape this space in the coming years:
- $ Encrypted Client Hello (ECH) — hides the SNI field inside the TLS handshake, eliminating the primary vector DPI uses for domain-based blocking. Once ECH adoption reaches critical mass, SNI-based blocking becomes impossible without full MITM.
- $ QUIC everywhere — HTTP/3 over QUIC encrypts more of the handshake than TCP+TLS. Tools that only handle TCP (GoodbyeDPI) will become increasingly irrelevant as services migrate to QUIC.
- $ Post-quantum TLS — larger key exchanges in TLS 1.3 with post-quantum algorithms change traffic fingerprints dramatically. DPI systems will need to re-learn traffic patterns, creating a window of opportunity.
- $ AI-powered DPI — censors are deploying ML classifiers that detect bypass tools by behavioral patterns rather than packet signatures. This arms race will push the field toward protocol transformation (NetVeil's approach) and away from packet tricks.
The cat-and-mouse game between censors and circumvention tools will continue to escalate. Packet-level tools like Zapret, GoodbyeDPI, and ByeDPI will remain effective against moderate DPI for the foreseeable future, but the trend is clear: advanced censorship requires advanced evasion. The tools that survive will be the ones that adapt fastest.
Tool Links
All three tools are open-source. Star the repos, contribute, and report bypass strategies that work on your ISP.
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