The explanation under that question and the FAQ answer linked below set out the rule to check against.
Open "Examples and legal text" under the question you were unsure about to see the rule and its source.
You were not sure about: Is it software, or a device or part that stores, processes or sends data?
Sources: CRA Art. 3(1), Art. 3(5)
You were not sure about: Is it a physical device, or software that people download or install on their own device, not just use in a web browser?
Sources: CRA Art. 3(1); Commission guidance C(2026) 5252 final (non-binding)
You were not sure about: Does a device or app need this online service for one of its features, and did that device or app's maker build the service, or have it built for them?
Sources: CRA Art. 3(1), Art. 3(2); recitals 11 and 12; Commission guidance C(2026) 5252 final (non-binding)
You were not sure about: Does it connect to another device or a network to send or receive data, even indirectly, in the way you intend or in a way people could predictably use it?
Sources: CRA Art. 2(1), Art. 3(8) to 3(10), Art. 3(23), Art. 3(24)
You were not sure about: Is it supplied for sale or use in the EU as part of a business activity, whether paid or free?
Sources: CRA Art. 2(1), Art. 3(22); recitals 15, 16 and 18
You were not sure about: Is it one of the products the CRA leaves out, such as a medical device?
Sources: CRA Art. 2(2) to 2(7); Delegated Regulation (EU) 2025/1535, Art. 1; Commission guidance C(2026) 5252 final (non-binding)