in all modesty
From Longman Dictionary of Contemporary Englishin all modestyin all modestyspokenPROUD used when you want to talk about something good you have done, but you do not want to seem too proud I think in all modesty that I can take some small credit for the team’s success. → modestyExamples from the Corpusin all modesty• In all modesty, I think I've matured quite a bit since those days.