Anti-block mode is a switch in Settings → Connection that splits the TLS handshake into smaller chunks. Together with REALITY, this evades deep packet inspection (DPI) used by carriers and state firewalls to detect VPN traffic by its handshake fingerprint.
Does it actually slow my connection?
Only the first second. Splitting the handshake adds 200–500 ms to the connect step, depending on your latency to the server. After the tunnel is up, throughput is identical to a normal connection — anti-block only manipulates the handshake packets, never the data stream itself.
When to turn it on
- Strict mobile carriers known to throttle VPN traffic (e.g. Telkomsel prepaid data, IndiHome on certain routes)
- Anywhere inside mainland China or Russia
- Public Wi-Fi at airports, hotels, or cafés that blocks 'unknown' protocols
- Any time you see 'connecting…' hang for more than a few seconds — auto-detect probably missed a DPI
When to leave it off
- Home Wi-Fi on a clean residential ISP
- Most office Wi-Fi — corporate firewalls block by category, not by protocol
- Mobile data on operators that don't fingerprint VPN (most EU, US, Japan, Singapore carriers)
Auto-detect (default)
If you leave the toggle on Auto (default), the app probes the network on first connect and turns anti-block on only when it detects DPI on the path. The manual override is in Settings → Connection → Anti-block: Off / Auto / On.