Online sessions are also provided

WhatsApp — end-to-end encrypted by default

WhatsApp messages and calls (including video calls) are end-to-end encrypted automatically, for everyone, with no setting to turn on. It uses the Signal Protocol, the same encryption technology used by the Signal messaging app and widely regarded as the industry benchmark. In practice this means only you and the other person on the call can access the conversation; not even WhatsApp can see or hear it.

One practical caveat, unrelated to the call itself: if chat backups are turned on (iCloud or Google Drive), those backups aren't end-to-end encrypted unless encrypted backup is separately switched on in WhatsApp's settings. Worth checking if any session-related chat history is kept.

Zoom — strong by default, fully end-to-end when switched on

A standard Zoom meeting is encrypted in transit and at rest, but the encryption keys are generated and held by Zoom's own servers. This means Zoom's infrastructure technically has access, similar to most mainstream video platforms, and that's Zoom's default for every meeting.

Zoom also offers genuine end-to-end encryption (E2EE) as an opt-in feature: the meeting host switches it on beforehand, and encryption keys are then generated on participants' own devices instead of Zoom's servers. The trade-off is that a few features stop working for that meeting, such as cloud recording, live transcription, in-meeting chat before/after, and a handful of add-ons, none of which a therapy session typically needs anyway. Everyone must join from the Zoom desktop or mobile app, not by phone dial-in, for E2EE to apply.

In short: Zoom is secure by default, but if full end-to-end encryption matters to you, it needs to be switched on for that specific meeting. It isn't automatic the way it is on WhatsApp.