The Great Firewall for travellers: what opens, what does not, and what to prepare before you fly

What the Great Firewall means when you are only visiting

"Great Firewall" is the informal name for the system that filters and controls internet access on mainland China. What a visitor notices is simple: many foreign services load slowly, hang, or do not open at all when you connect through a network inside the mainland, whether that is hotel Wi-Fi, café Wi-Fi or a SIM bought in China.

The key point is that the result depends on the route your data takes to the internet, not on the phone or the app. The same handset may open Instagram on a travel eSIM and fail on hotel Wi-Fi. Filtering details change often, so the table below is a general picture, not a guarantee.

Popular apps on a mainland Chinese network

For a broader app list with connection options, see “Google, LINE, Facebook and Instagram in China, and Whether to Use an eSIM, Chinese SIM, Roaming or Pocket WiFi” and “China eSIM Without a VPN: How It Works and What to Check Before Buying”.

Why roaming and travel eSIMs behave differently

With roaming or a travel eSIM from a non-Chinese provider, your data usually travels through a gateway outside the mainland before reaching the internet, much like ordinary roaming. That is why foreign apps usually open. Hotel Wi-Fi and Chinese SIMs exit inside the mainland, so they meet the full filtering.

• Nobody can guarantee every app on every network; some may be slow or fail temporarily.
• Test LINE, Google Maps and any banking app as soon as you switch the eSIM on at the airport or first hotel.
• If you are on hotel Wi-Fi, foreign apps may fail; switch Wi-Fi off and use mobile data instead.

Hong Kong and Macau are not behind it

Hong Kong and Macau are special administrative regions with internet access separate from the mainland. Google, LINE, Instagram and other apps work normally on networks in those two cities. When you cross the border into Shenzhen or elsewhere on the mainland, the network you use changes, so check which network your SIM has joined.

A neutral word on VPNs

Some travellers consider a VPN, but the legal position for visitors is a grey area, many VPN services are blocked or unreliable in China, and we do not recommend any brand. Installing one in advance does not guarantee it will work. Read the basics in “What is a VPN? How it works, what it is good for, and whether it is actually safe” and “Using a VPN while travelling: what to know before switching it on”, and check current rules from official sources before deciding.

Common misunderstandings

• "An eSIM opens everything" is not always true; some networks or moments are slow and a few apps may not connect.
• "The app will not open, so the data is broken" is often just filtering; switch between Wi-Fi and mobile data before concluding.
• "Chinese apps work instantly" is also false; many ask for identity or a Chinese number, so set them up early and read “Chinese Social Media Apps vs Thai Apps: What to Install”.

What to prepare before you fly

1. 1Install the eSIM on home Wi-FiInstall the profile in advance but leave it off, then enable data roaming for the eSIM line on arrival. See “How to install an eSIM, step by step (iPhone and Android)”.
2. 2Keep your Thai SIM onA data-only eSIM has no phone number, so the Thai SIM stays on for bank SMS and OTP.
3. 3Set up paymentsLink a Visa/Mastercard to Alipay or WeChat Pay and verify your passport before flying. See “Using a Credit Card in China and Linking a Card to Alipay or WeChat Pay”, and keep some cash and a physical card as backup.
4. 4Download offlineOffline maps, tickets, hotel addresses in Chinese, and music or video. See “Offline maps that actually work when the data runs out”.

See eSIM plans for China

Frequently asked questions