In U.S. law we have the "imminent lawless action" test from Brandenburg v. Ohio as one of the main tests for whether speech can be regulated because of its likelihood of successfully encouraging others to break the law.
https://en.wikipedia.org/wiki/Imminent_lawless_action
Even when speech fails the Brandenburg test, it is still not literally considered a form of violence, but something else like incitement (or sometimes part of a conspiracy or criminal enterprise or something).
All of those legal discussions are pretty much expressly about not conflating speech with violence, even if speech sometimes has a role in encouraging people to commit violence.