Paste broken Preeti text, type Nepali phonetically in English letters, or paste normal Unicode — drop it in below. No need to know which one you have.
Manual mode
All three boxes convert live and stay independently editable, so a manual fix here is never silently overwritten by the automatic converter above.
Double a vowel for the long form: a→अ, aa→आ, i→इ, ii/ee→ई, u→उ, oo→ऊ. Aspirated consonants: kh, gh, chh, jh, th, dh, ph, bh. Retroflex sounds use a "2": t2, d2, n2, sh2 → ट, ड, ण, ष. "x" is a shortcut for छ. ksha/gya are typed whole for क्ष/ज्ञ. Case doesn't matter.
Typing casually with English words mixed in — "bro", "office", "tax", "please call me" — is handled automatically: those words stay in English instead of turning into nonsense Devanagari. Turn this off with "Convert everything" above if you ever want every word forced through Nepali.
Shipping a guessed Devanagari mapping would do more harm than not having it. Send a short Kantipur or Kalimati sample with its correct Unicode text on WhatsApp and we'll build and verify it the same way Preeti was done.