Add Vietnamese accents to text
Paste Vietnamese written without its tone marks and get the marks put back. Where the letters could be more than one word — which is most of the time — every candidate is one click away instead of silently guessed for you.
Why no tool can finish this job
This dictionary holds 895 toneless spellings taken from FluentViet's own curriculum, and 464 of them — 52% — map to more than one real word. ma alone is six: ma, má, mà, mả, mã, mạ. Software can rank them; only context decides, which is why the ambiguous ones here stay clickable rather than pretending to be certain.
Where the word next door settles it, this page uses it: 3603 attested pairs from the same curriculum override the raw ranking, which is how pho bo comes back as phở bò and not phở bố — soup, not father. Beyond a pair of words, a static page is out of context to use, and it stops guessing.
The same fact is why Vietnamese does not forgive a flat tone out loud. Writing pho for phở is a typo a reader forgives. Saying it is a different word, and the person across the counter hears the word you actually said.
Now hear the difference.
Restoring marks on a page is guesswork. Saying them is not — FluentViet listens to your voice, scores the tone you actually produced, and the characters answer only when you get it right.
Start free →More free things, no login: the pronunciation guide, the other slang decoder, and the blog.