An eSIM, roaming or a local SIM in China differ in one thing that matters more than price or speed: the country where your data exits to the internet. On your home carrier's roaming and on most travel eSIMs, it exits in the carrier's home country, so Chinese filtering never sees it and Google, Instagram and WhatsApp work without a VPN. On a Chinese SIM or hotel Wi-Fi, it exits in China, filtering applies, and travelers add a VPN. Once you know which side of that line a plan is on, the choice is easy.
Below: how roaming actually routes your traffic, why "eSIM" can mean two opposite things, what a local SIM gets you, and a recommendation by trip length.
How roaming routes around the filter
When your phone roams on a foreign SIM, it connects to a Chinese tower only for the radio signal. The tower identifies the SIM as a visitor and, under the roaming agreement between carriers, tunnels your data back to your home carrier's network. Your traffic reaches the public internet in your home country. To the Chinese international gateways this is carrier-to-carrier transit, not a user session, and it is not filtered. That is the entire reason foreign apps work on roaming: it is routing at the network level, not an app doing anything clever.
Two costs come with it. Money: roaming packages are more expensive than local data, and without a package the default per-day rate can be steep, so check with your carrier before you fly. Latency: every request takes a round trip through the home network, which messaging and maps tolerate and video calls sometimes do not.
"eSIM" means two different things
A travel eSIM is a profile of a foreign carrier, often based in Hong Kong, Singapore or Europe, that visits China as a roaming guest. Data exits in that carrier's country, filtering does not apply, your usual apps work. You buy it online, install it from a QR code, and it is live before you land. It is cheaper than home-carrier roaming, but you need an eSIM-capable, unlocked phone, and most plans are data-only.
An eSIM from a Chinese carrier is a local SIM in digital form. It exits in China and is filtered like any local connection. Read whose profile you are buying; if the listing says foreign services work without a VPN, it is almost certainly a foreign carrier's profile.
What a local SIM gives you
China Mobile and China Unicom sell tourist SIMs at airports and in stores against a passport. It is the cheapest and fastest data you can get, with 4G and 5G nearly everywhere, and it comes with a Chinese number, which some local apps want. The trade-off is that it is Chinese internet: Google services, Western social networks and messengers are unreachable, and travelers who want them use a VPN that was installed and tested before departure. The preparation and the protocol question are covered in VPN for China: what travelers need to know.
Hotel and café Wi-Fi is the same category: a Chinese connection, sometimes a very fast one, with the same rules.
Which to choose
A few days. Roaming or a travel eSIM. Nothing to configure, almost no risk of being cut off, and the premium for a short stay is small.
One to two weeks. A travel eSIM for your usual apps plus, if your phone has a second slot, a local SIM for speed and local apps. Or a local SIM with a VPN you have tested at home.
A month or longer. A local SIM with a VPN as the primary setup, and roaming kept as an emergency option: switch it on for a few minutes on a day when the VPN will not connect.
Working remotely. Do not rely on a single path. Carry both a travel eSIM and a VPN, and expect to switch between them.
What to check before you fly
- Your carrier's roaming rates for China and how to activate a package. Disable any automatic top-up to the most expensive tier.
- Whether your phone supports eSIM and is carrier-unlocked; phones bought on installment plans are sometimes locked.
- If you are taking a local SIM: VPN installed, two protocols configured, connection verified on What Is My IP, WebRTC and IPv6 leak tests clean.
- WeChat and Alipay installed with a card linked, whatever connection you choose.
A note on privacy
Roaming and travel eSIMs solve reachability, not privacy. Your carrier still sees the same domains it sees at home, and websites still see your real address, just from another country. If you want the hotel network or the local carrier not to see your browsing, a VPN remains a separate tool, on roaming too. What a carrier sees with and without a tunnel is in What can my ISP see.
Dual-SIM setups
Most current phones take a physical SIM and an eSIM at once, which makes the best combination easy: a Chinese SIM for cheap, fast data and a local number, and a travel eSIM that you switch to as the data line whenever you need your usual apps. Set the eSIM as the default for data only when you need it; leaving it on all the time means paying foreign-carrier rates for local traffic. With a VPN configured on top, you also have a third path for the days when one of the others misbehaves.
404 VPN runs over any connection, local SIM, eSIM or Wi-Fi, with VLESS and WireGuard, DNS inside the tunnel, a kill switch and locations in Hong Kong, Singapore, Japan and Thailand. The free plan of 5 GB a day is enough to test before you go. Start on the home page.