HumanFlow does two things. It rewrites text so it reads more like a person wrote it, and it scores text for how machine-typical it looks — sentence by sentence rather than as one number for the whole document.
The rewriter is for drafts that a language model helped produce and that read like it. Machine-drafted prose tends toward even sentence lengths, predictable connectives and paragraphs of near-identical weight. The rewriter breaks that pattern up and applies a tone you choose.
The detector reports each sentence as human, AI, or mixed. The emphasis on mixed is deliberate: most real documents are a blend, and a single percentage flattens that into something it cannot support. Seeing which four sentences are flagged is more useful than being told the document is 62% something.
What HumanFlow does not do is promise a detection outcome. We do not claim to beat, bypass or defeat any AI detector, and we publish no bypass rates — nobody can measure that honestly, because detectors change without notice and disagree with each other on identical text.
It also does not check grammar, generate drafts from scratch, or translate. It works in English only. If you need writing corrected as you type across every app, a general writing assistant is the better tool and we say so on our comparison pages.
You can use both halves without paying. The free plan covers 2,000 humanizer words and 10,000 detection words a month, with up to 1,500 words in any single scan.