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AI humanizer for writers

Writers use AI to speed up drafts, then spend the saved time fighting the residue it leaves. Leap scores and cleans your draft right in the browser so you can revise in your own voice.

Publish in your voice

Paste your own draft and try it. Detection and humanization are free, run locally in your browser, and require no account. Your text is never sent anywhere.The detector gives you a 0 to 100 AI signal score and highlights the sentences that weigh most. The humanizer does a cleanup pass: it swaps stock AI phrases, removes em dashes and invisible characters, and marks uniform sentence lengths so you can vary them yourself.

The writer's five pains

  • Speed vs voice. AI drafts 10x faster than longhand, but the output reads like a model, not like you. You end up rewriting the whole thing and losing the speed advantage.
  • Editor-side detectors. Many publications run AI detectors on submissions, and a flagged piece can get killed without discussion. Detectors are signals, not proof, and they can be wrong, but the risk lands on you.
  • SEO penalty fear. Google's helpful content system targets low-effort content, and generic AI-sounding prose is often part of that picture.
  • Byline risk. A public claim that one of your pieces was AI-generated can damage your reputation more than the speed gain was worth.
  • Client contracts. Agency and ghostwriting contracts increasingly require human-authored content, and violation can void payment.

How Leap fits a writer's workflow

Leap is built for the draft, revise, verify loop. Each feature targets a specific stage:
  • Sentence-level scoring. Paste a finished draft into the detector. You see a 0 to 100 score from writing signals: uneven vs uniform sentence length, stock AI phrases, hedging and transition words, em-dash density, and repetition, plus highlights on the sentences that weigh most. Revise the flagged ones by hand where voice matters.
  • Cleanup humanization. The humanizer replaces stock AI vocabulary, removes em dashes and invisible characters, adds contractions where natural, and flags uniform-length sentences for you to vary. Your argument stays yours; the revision decisions stay yours.
  • Privacy. Everything runs in your browser. Nothing is uploaded, stored, or trained on, which matters for under-embargo assignments and confidential client work.

Five realistic scenarios

How different writers use a detector and cleanup pass in practice.

Scenario 1: 2,000-word blog post for a B2B client

You brainstorm with Claude, draft sections in ChatGPT, stitch, then run the detector before sending. The highlights show which sections still read as machine-written, so you rewrite those by hand instead of guessing. The client runs their own detector on deliverables, so you check with the same kind of signals first.

Scenario 2: Newsletter post in your established voice

You have 20k subscribers who know your voice. AI makes drafting faster but flattens the cadence that built the audience. Run the draft through Leap, then pick three paragraphs and rewrite them by hand, the peak moments that carry your reader.

Scenario 3: Op-ed submitted to a national outlet

The outlet bans AI-generated prose. Your research and outlining happened with AI but the draft is handwritten. Still, stiff academic-register phrasing can trip detectors. Use the detector to spot flagged sentences and rewrite them before submission.

Scenario 4: Novel draft, chapter skeleton

You use AI to push past writer's block on connective scenes: a character walks across a room, a flashback transition. Clean up the connective prose but keep voice-carrying passages, dialogue, internal monologue, fully your own. Never run a humanizer over voice work.

Scenario 5: LinkedIn thought-leadership for a founder

You ghostwrite posts for a CEO. AI drafts the skeleton, you transcribe the CEO's voice notes over the top, then clean up the residue before posting. Feeds tend to down-rank content that reads as generic and machine-like.

Responsibility note

A humanizer is a finishing tool, not a content-creation tool. If your piece has no original reporting, no original argument, and no original voice, a cleanup pass will not fix that, and should not. Leap does not guarantee passing any detector and does not promise to bypass any checker. An AI score is a signal, not proof: detectors can be wrong, and a score must never be the only basis for accusing anyone of using AI. See our methodology for how we think about detection quality, and our primer on AI vs human writing for the specific patterns to watch for.

Frequently asked questions