For all intents and purposes is the usual form of the phrase meaning in every practical sense. For all intensive purposes is a fairly common eggcorn derived from the original phrase. It’s often heard in speech, but it’s rare in published writing because it generally doesn’t pass through the editorial process.





Examples

Although for all intensive purposes doesn’t make much sense, examples such as these are not hard to find:






It was a questionable call in the 81st minute that for all intensive purposes decided the outcome. [Bleacher Report] The student was sharing a story with another student about “Amanda” stealing her fake I.D. Slade reassured the audience that he changed the name for all intensive purposes. [The Quinnipiac Chronicle] For all intensive purposes, Tennessee Volunteers Head Coach Derek Dooley can start packing his bags. [Her Game Life]

But in more carefully edited writing, for all intents and purposes, as used below, is the standard form: