The quickest way to check is to search the site's domain in OONI Explorer, a free database of censorship tests run by volunteers in more than 200 countries. For China specifically, dedicated firewall checkers give you a faster yes or no.
Step by step
- Search OONI Explorer. Type the domain (for example, bbc.com) into the search bar, then filter by country and date. Results show whether recent tests from local networks loaded normally or came back as "anomaly" or "confirmed blocked." It also covers apps like WhatsApp, Telegram and Signal. Anomalies aren't always censorship, so look for a pattern across many tests and networks.
- Run a China-specific test. GreatFire's analyzer compares probes inside mainland China with a control server outside and tells you how a URL is being blocked, such as DNS poisoning or a connection reset. Comparitech also runs a simple blocked-in-China checker where you paste a domain and hit Check.
- Read the country report. Freedom House's Freedom on the Net report covers 72 countries and notes which social networks, messaging apps and news sites are blocked, plus whether users have been arrested for online activity.
- Ask someone there. Blocks can differ between mobile carriers and home broadband, and change around elections or protests. A quick message to a local contact confirms what the tools show.
Testing from inside the country
You can also install OONI Probe on your phone and run tests yourself while traveling. Be careful with that: the EFF warns that running it can draw attention, and some governments block it. In places where censorship monitoring is sensitive, stick to the online lookups from home.
If a site you rely on is blocked, check whether VPNs are legal at your destination before you fly.