VPN not working in China? Here is what to check
China's Great Firewall does not just fingerprint VPN protocols — it actively probes servers it suspects are proxies, and it maintains IP blocklists that get updated constantly. A VPN that worked yesterday can stop today for three different reasons, and the fix depends on which one it is. This page explains how to tell them apart and what actually helps.
AVEE VPN — a VLESS/Reality app for Android and Windows, with a free trial to test it on your own connection. See the apps and where it's available →
Narrow down the cause
| What you see | Likely cause | Next step |
|---|---|---|
| Connects for a moment, then drops | Active probing flagged the server after first contact | Switch to a Reality/actively-probing-resistant transport |
| Never connects, any server, same app | The protocol itself is fingerprinted at the DPI layer | Switch protocol, not just server |
| Worked for weeks, stopped on one specific server | That server's IP was added to a blocklist | Change server first — the cheapest fix |
| Everything got worse around a specific date | Temporary tightening around a sensitive political date or event | Wait it out; obfuscated transports have better odds during this window |
The fix list
- Switch to a Reality-based transport. VLESS with Reality is built specifically against active probing — it borrows a real website's TLS identity so a probe sees an authentic handshake. Standard OpenVPN, WireGuard and IPSec are both fingerprinted and probed. See what is the Reality transport.
- Change server. If only one server stopped working, its IP is likely blocklisted — a different location often reconnects immediately with the same protocol.
- Use port 443. Ordinary HTTPS traffic on this port is far more expensive for a filter to block without breaking the wider web.
- Avoid re-testing constantly during a tightening window. Filtering measurably tightens around Party congresses, sensitive anniversaries and major political events, and eases afterward — repeated failures during these windows are the restriction, not your setup.
- Update the app. Server lists and certificates go stale; an outdated build can fail silently with no useful error.
Why China breaks VPNs that work everywhere else
Most countries filter VPN traffic by recognising the protocol's signature — an easier problem. China adds active probing: when the firewall sees traffic it suspects is a proxy, it connects to that exact server itself and checks whether it behaves like a normal web server. If it does not, the server gets blocked — regardless of whether the protocol was ever fingerprinted. This is a different, harder problem, and it is why a transport that survives DPI filtering in Turkey or Kazakhstan can still get caught in China. See how the Great Firewall works and how ISPs block VPNs for the underlying mechanisms.
Where AVEE fits
AVEE uses VLESS with the Reality transport by default — built specifically to resist active probing, not just protocol fingerprinting. That said, no VPN can honestly promise it stays ahead of China's filtering on every network, every day; connectivity there changes constantly. The honest way to know is the free trial (about 1 GB, up to 3 days) on your own connection. Plans start at $1/month.
If your current VPN will not connect here, AVEE uses VLESS/Reality — try it on this network first.
FAQ
- Why did my VPN suddenly stop working in China?
- Usually one of three things: the server IP got added to a blocklist, active probing detected the protocol and blocked it, or a censorship tightening happened around a sensitive date (Party congresses, anniversaries, major events). Switching server and protocol fixes the first two; the third lifts on its own.
- What is active probing and why does it break VPNs that work everywhere else?
- The firewall connects to a server it suspects is a proxy and checks how it answers. If it does not behave exactly like a normal website, it gets blocked — even if the protocol itself was never fingerprinted. This is why some transports that survive DPI in other countries still get caught in China.
- Does changing servers help if a VPN stops working in China?
- Often yes, if the specific IP was blocklisted rather than the protocol itself. It does not help against active probing, which targets the server's behavior, not its address.
- Is it legal to use a VPN in mainland China?
- Only government-approved VPNs are authorised. Unauthorised VPN provision is penalised, and individual use sits in a grey area that has occasionally been enforced. This is general information, not legal advice.
Sources
- Top10VPN — VPN censorship methods, including active probing — checked 2026-08-29
- GreatFire — analyzer of blocking in China — checked 2026-08-29