CaseKit

Convert text to snake_case, kebab-case and Title Case

Paste up to 5,000 characters and get 5 cases at once: UPPER, lower, Title Case, snake_case and kebab-case, one result per line.

What happens with text longer than 5,000 characters?

It is cut at 5,000 characters and the result says so.

How is a name like UserAccountID split?

At every lower-to-upper change and before the last capital of a run of capitals, giving user_account_id and user-account-id.