About GhostWriter AI

Why we built this

AI writing tools are useful. AI detectors are imperfect. The gap between them creates a real problem: students, writers, and professionals using AI to assist their work get flagged as cheaters — even when they aren't.

We built GhostWriter AI to solve the technical side of that problem. Not to help anyone cheat — but to give writers a tool that makes AI-assisted content sound like the person who wrote it actually wrote it.

How it works

AI detectors don't read for meaning. They measure two statistical properties of text:

• Perplexity — how predictable the next word is. AI always picks the most likely next word, keeping perplexity low and flat. Human writers are surprising.
• Burstiness — the variation in sentence length. AI produces uniform, medium-length sentences. Humans mix short punchy sentences with longer, winding ones.

GhostWriter AI is trained to maximise both signals simultaneously. It uses Claude, one of the most capable large language models available, with prompts that explicitly target detector metrics rather than just asking for “natural-sounding” text (which doesn't move the needle).

For the Advanced mode, the text goes through a second self-critique pass: the model reads its own output, hunts the remaining AI tells, and fixes them. This measurably lowers detector scores versus a single pass.

What we optimise for

• GPTZero — perplexity + burstiness scoring
• Turnitin — AI writing detection module
• Originality.ai — the strongest commercial detector
• ZeroGPT — sentence-level AI identification
• Copyleaks — cross-language AI detection
• Winston AI — academic and professional content
• Sapling, Writer.com, Crossplag

Our principles

• Free to use.The free plan needs no card and no signup. AI tools shouldn't require a subscription just to try them.
• Honest about what we are.The on-site detection score is a heuristic estimate — we say so clearly. We don't claim 100% guarantee against any detector.
• No data retention. We do not store the text you submit. Free-tier usage is tracked by hashed IP only, with no identifiable data kept.
• Responsible use. GhostWriter AI is a writing tool. Using it to submit fully AI-generated work as your own in a context that prohibits it is your responsibility, not ours.

The team

GhostWriter AI is built and maintained by a small team of engineers and writers who work with AI tools every day. We launched in 2026 and have humanized over 4 million words for users in more than 50 countries.