About
Why ESL Humanizer exists
Hundreds of millions of people write in English as a second language. Their ideas are as good as anyone's, but their writing is often judged on its English first — and increasingly, by AI detectors that mistake plain, careful second-language writing for machine output.
The evidence for that bias is strong. In a peer-reviewed Stanford study, seven AI detectors misclassified an average of 61% of human-written TOEFL essays as AI-generated, while judging native speakers' essays almost perfectly (Liang et al., 2023). We built ESL Humanizer so non-native writers can present their own work in natural English — and be judged on their ideas.
What we stand for
Your ideas, not ours
The tool is built to rewrite text you wrote. It is instructed never to add claims, examples or ideas that weren't in your original.
Natural, not impressive
We keep your register and approximate level. An undergraduate essay should still read like an undergraduate wrote it — just fluently.
Every change visible
Edits are highlighted word by word, so you always know exactly what you are submitting and can explain it.
Meaning is checked
Each rewrite gets a meaning-similarity score. Below 85/100 we warn you that the rewrite may have drifted.
How it works
When you paste text, it is rewritten by a large language model (Anthropic's Claude) following strict instructions: preserve the meaning exactly, keep your register, fix grammar and awkward phrasing, and don't add filler or new ideas. The model then rates how closely its rewrite preserves your original meaning. When detection scoring is enabled, we also send the before and after versions to an AI-detection service to estimate how each reads.
What we won't do
- Write essays or assignments for you from a prompt.
- Promise that your text will pass any AI detector — no honest tool can.
- Help disguise AI-generated work as your own. See where we draw the line.
Your text
Your text is sent to our AI provider only to produce the rewrite, and to the detection service when scoring is on. We don't save your writing to our database.
Our guides
Our guides are written by the ESL Humanizer team. Every statistic links to its original source — peer-reviewed research or the organization that published it — and we update pages when the evidence changes.