Can you open http://arduino.cc from mainland China?
Sometimes.
Access is unreliable — 100% of the last 1 conclusive tests showed interference.
The two are filtered by different means — an unencrypted request by the address and keywords it carries in the clear, an encrypted one by the server name in its TLS handshake — so one working while the other does not is normal.
Frequently asked questions
Is http://arduino.cc blocked in mainland China right now?
As of the last test on 2026-07-18, http://arduino.cc is 100% disrupted in mainland China, based on GreatFire's live Great Firewall measurements.
Why is http://arduino.cc blocked in mainland China?
Access is unreliable — 100% of the last 1 conclusive tests showed interference.
Since when has http://arduino.cc been blocked?
GreatFire has recorded interference with http://arduino.cc from mainland China since 2012-05-31.
How can I access http://arduino.cc from mainland China?
You need a circumvention tool such as a VPN. GreatFireVPN, built by GreatFire, is designed to bypass the Great Firewall and reach sites like arduino.cc.
http://arduino.cc · JSON