One sentence a day. That is the whole habit.
Write a single line about today. Every morning, OneLineDiary opens with what you wrote on this day last year, and the year before, and the year before that.
Sunday 20 September 2026
Signed the lease. Tiny flat, huge window, first time the keys are mine.
Viewed nine flats, liked none, ate chips on the kerb outside the ninth.
Decided I am moving out of this city by next autumn. Told nobody yet.
Why it sticks
Too small to skip
280 characters, one box, saves as you type. Thirty seconds and it is done.
Memory does the work
You never scroll back. The day you wrote about a year ago is on the page when you open it.
Yours to keep
Export the whole diary as CSV or JSON at any time. Delete your account and every line goes with it.
Optional morning email with your this-day-last-year line, sent at the hour you choose in your own timezone.