About
Refrazr is built by a team of engineers and NLP researchers who got tired of watching well-written text get flagged as AI-generated — and decided the fix wasn't chasing detector scores, but writing that actually reads like a person wrote it. The pipeline was rebuilt in July 2026 around a single naturalness-focused rewrite pass, after our own benchmarking showed the previous rule-based approach was itself the tell. The full pipeline and the benchmark numbers behind it are published at /methodology.
What we do
AI detectors — tools like GPTZero, Turnitin's AI indicator, Sapling, Originality.ai, and Copyleaks — don't look for plagiarism. They look for statistical patterns in how language models generate text. Those patterns are real and consistent: LLMs produce unnaturally uniform sentence lengths, overuse certain transition phrases, construct symmetrical parallel clauses, and favor a specific vocabulary set that signals machine authorship.
Refrazr addresses this with one clean rewrite pass: the whole draft goes to the model in a single call, under a compact naturalness instruction — write this the way a sharp person actually would, uneven rhythm, plain verbs, one voice — with a hard rule that no name, number, date, or claim gets changed or invented. The result reads like a person wrote it because the model is writing naturally, not because we're gaming a specific detector's score.
We help content creators working with AI drafts, non-native English speakers who use AI to overcome language barriers, marketers producing content at scale, and anyone whose genuine writing has been incorrectly flagged by an AI detector. The free tier is permanently free — 500 words per day, no credit card required.
Our approach
Simple paraphrasers change what the text says. Refrazr changes how it was written. The whole draft goes to the model in a single call, under one instruction — write this the way a sharp person actually would — with a hard rule that no name, number, date, or claim gets changed or invented.
After the rewrite, a light cleanup pass strips model preamble, normalizes spacing, and swaps stray em dashes — that's the whole post-processing layer. No vocabulary swap lists, no burstiness enforcement, no scoring-and-retry loop. We deleted the 150+-rule engine that used to run here in July 2026, after benchmarking showed its mechanical edits were themselves the tell.
We judge output with Claude Opus, blind, on the same corpus, on two questions: does this read like a person wrote it, and is every fact from the source still intact. The current pipeline scores 78% "written by a human" against roughly 15–25% for the old rule-based engine. We don't test against or optimize for any specific third-party detector, and we don't claim the output beats one.
We show you an AI-pattern score before and after humanization, using the same heuristic analysis our free detector runs. The pipeline and the benchmark numbers behind it are fully documented — see our methodology page.
Who built this
We are engineers and NLP researchers who got tired of watching well-written text get flagged as AI-generated — and decided to understand how detectors actually work, and why they flag writing they shouldn't.
The problem with most humanization tools is that they approach the wrong signal. Detectors like GPTZero and Turnitin do not just check for unusual words. They measure structural properties of text: burstiness (the variance in sentence lengths), perplexity (how predictable word choices are), transition density, vocabulary distribution, and passive-to-active ratios. A tool that only swaps synonyms does not move these metrics.
We spent over a year building a post-processing pipeline that worked at the structural level — then deleted most of it. In July 2026, benchmarking against a strict reader (Claude Opus) showed the 150+-rule layer we'd built was itself reading as the AI tell. The current pipeline is a single naturalness-focused rewrite pass instead: simpler, and it benchmarks better.
The current pipeline's quality bar is a blind read from Claude Opus on two questions — does this read like a person wrote it, and is every fact from the source still intact — not a score from any specific detector. We don't test against or optimize for GPTZero, Turnitin, Sapling, Originality.ai, or any other detector, and we don't claim the output beats one. The methodology and the actual benchmark numbers are published at /methodology — we do not keep this proprietary because confident results should be reproducible.
The pricing reflects our cost structure. Every request runs on DeepSeek's v4-flash model via OpenRouter, which costs a fraction of what frontier closed models charge per call. We pass most of that margin to users. Refrazr Pro is $6.99/mo. Undetectable.ai charges $19. The difference comes from the model choice, not a gimmick.
If Refrazr does not work for your text, we should not have your money. Refund policy: 7 days, no questions asked. Email Contact us from the address you used to buy.
Writing about Refrazr? Facts, boilerplate and logo files live on the press page.
Who uses it
AI drafts save hours of work, but raw AI output reads like AI output. Editors, readers, and Google's quality systems all notice. Refrazr converts AI-generated drafts into content that reads like it came from a skilled human writer — with natural rhythm, genuine variation, and no AI jargon.
Using AI to help express ideas in a second language is completely legitimate. Being flagged as an AI author for doing so is not fair. Refrazr helps non-native English speakers submit work that reflects their thinking without triggering false-positive detection.
Marketing teams using AI to scale content production need that content to rank, convert, and not get flagged. Refrazr runs at API scale — the Business plan includes API access for teams that need to process content programmatically.
AI detectors have real false-positive rates. Some human writers have writing styles that happen to trigger detection. Refrazr rewrites your full draft in one pass, so text that's triggering a detector — even if you didn't write it with AI — comes back reading naturally, without you needing to guess which specific sentence is the problem.
Privacy
We don't store your text. The process is: receive text → rewrite → return result → discard. Nothing you paste into Refrazr is logged to a database, shared with third parties, or used for model training. The only metadata we log is what's required for billing: timestamp, word count, and success/fail status.
Read the full details in our Privacy Policy. The short version: your content is yours and we never see it after the request completes.
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Free tier: 500 words/day, no account required.
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