GoodByeDPI GUI offers three modes. This page explains what each does, when to use it, and how they differ.

Deep Packet Inspection (DPI) is a technology ISPs use to inspect the contents of your internet traffic. It's often used to:

• 🚫 Block specific websites
• 🐢 Throttle certain services
• 📊 Log traffic patterns

GoodbyeDPI doesn't encrypt your traffic (that's a VPN's job). Instead, it tricks DPI systems by fragmenting the very first packet of each connection, so the DPI filter can't identify what you're connecting to.

Splits the TLS Client Hello packet into fragments and sends them in reverse order, plus injects a fake packet with a wrong TCP sequence number that the DPI sees first.

Start here. It's the default for a reason — works on most ISPs and gives the best speed.

Uses automatic TTL detection to figure out how far the fake packet needs to travel, then fragments more conservatively.

Try this if:

• Fast mode causes slow loading or hanging connections
• Some sites work but others don't
• You're on a mobile hotspot or unusual network

You supply the arguments yourself. The app passes them straight to goodbyedpi.exe.

• Fast & Compatible both fail
• You want to test a specific combination
• You're following a tutorial for your ISP
• You want a highly-specific setup

For stubborn ISPs:

-f 2 -e 40 --native-frag --reverse-frag --max-payload

Aggressive bypass:

-9 --fake-gen 5 --fake-resend 2 --auto-ttl --min-ttl 3

With DNS redirection:

-6 --dns-addr 1.1.1.1 --dns-port 53 --dnsv6-addr ::1 --dnsv6-port 53

📖 See Custom Arguments for the full reference.

        ┌─────────────────────────┐
        │   Websites not opening? │
        └────────────┬────────────┘
                     │
                     ▼
        ┌─────────────────────────┐
        │  Try  ⚡ Fast  first.    │
        └────────────┬────────────┘
                     │
         ┌───────────┴────────────┐
         │                        │
      Works ✅               Doesn't work ❌
         │                        │
         ▼                        ▼
     🎉 Done!         ┌──────────────────────┐
                      │  Try 🛡 Compatible.   │
                      └──────────┬───────────┘
                                 │
                     ┌───────────┴──────────┐
                     │                      │
                  Works ✅              Doesn't work ❌
                     │                      │
                     ▼                      ▼
                 🎉 Done!        ┌──────────────────────┐
                                 │  Go 🔧 Custom mode.   │
                                 │  See Custom Args.     │
                                 └──────────────────────┘

Both Fast and Compatible use GoodbyeDPI's built-in mode shortcuts:

The presets are documented in the official GoodbyeDPI README.

• 🔄 Always try Fast first. It solves 90% of cases.
• 🎯 Don't stack modesets. Using -6 -5 together is undefined behavior.
• 📝 Save your working args. If a Custom combo works, copy it somewhere safe.
• 🧪 Test after 30 seconds. Give pages time to fully load before concluding it doesn't work.
• 🚫 No VPN simultaneously. They'll fight each other.