if truth be told

if (the) ˌtruth be ˈknown/ˈtold

used to tell somebody the true facts about a situation, especially when these are not known by other people: None of the students really liked the new teacher. In fact, if the truth be told, everyone was rather afraid of him.
See also: if, known, told, truth
Farlex Partner Idioms Dictionary

if truth be told

To be perfectly honest, to present all the facts of a case. James Patterson used it in his novel, Roses Are Red (2000): “I am a little scared, truth be told.” See also fact of the matter; truth to tell.
See also: if, told, truth
The Dictionary of Clichés by Christine Ammer
See also:
  • get (one's)/the facts straight
  • get the facts straight
  • tell the truth
  • to tell (you) the truth
  • the whole (something) thing
  • the whole thing
  • the... thing
  • brass tacks
  • facts are stubborn things
  • all things to all people