Phrasly.AI (phrasly.ai) is a US company founded in 2023 that offers a range of AI tools geared toward students and professional writers.[1] Its products include an AI detector, plagiarism checker, and AI humanizer that rephrases text generated by ChatGPT and other large language models (LLMs) to sound more human.
In the review below, we focused primarily on the AI detector and its overall accuracy.
Pros
- Free and unlimited AI detections
- Detected AI in 7 out of 7 texts generated by LLMs
- Passed 10 out of 10 plagiarism tests
- Excellent user rating on Trustpilot
Cons
- Testing produced 5 false positives
- Only 2 of 8 humanized articles were flagged for AI
- AI detection reports cannot be downloaded or shared
Features
- AI detector: Check text for signs of ChatGPT, Gemini, or other AI writing.
- Plagiarism checker: Determine whether content matches existing sources.
- AI humanizer: Make AI-written material sound human.
- Watermark remover: Remove AI watermarks from generated text.
- Content generator: Enter prompts to generate fully written articles.
- Translator: Translate text into 100+ languages.
- Thesis generator: Automatically write thesis statements.
- Counter: Instantly count words, characters, and sentences.
- API
Pricing Plans
| Free | Basic | Unlimited |
| Some features require an account | $2 for 3-day trial, then $39.99/month or $239.88/year | $20/month or $131.88/year |
| Unlimited AI detections | Unlimited AI detections | Unlimited AI detections |
| Limited AI humanizations and content generations. | Unlimited AI humanizations and 6,000 content generation words/month. Excludes plagiarism checker. | Unlimited AI humanizations, 30,000 content generation words/month, and 20,000 plagiarism check words/month. |
Business API Plan
For a minimum payment of $100/month, customers can integrate the AI detector API and humanizer API into their company’s products.[2] Each API request draws from the same shared balance of credits:
- $.02/1K words for AI detection (5M words at $100/month)
- $.14/1K words for humanization (714K words at $100/month)
Customers requiring higher monthly word volumes can contact customer support for custom rates and bulk discounts.
Test #1: Phrasly.AI vs. LLMs
Our first test was designed to measure how well Phrasly.AI detects LLM-generated writing before any edits or humanizer tools are applied.
To keep the test consistent, each of the LLMs listed below received the same prompt. We then scanned the rendered texts with Phrasly.AI to test the platform’s AI detection accuracy.
Prompt Used
“Write a 500-word article about polar bears using a natural, human-like writing style with the goal of avoiding AI detection. Provide factual information only and do not use em dashes.”
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| LLM | Test Result | Proof |
| ChatGPT – 5.5 Thinking Model | 100% AI
✅ |
 |
| Claude – Sonnet 4.6 Extended | 100% AI
✅ |
 |
| Google Gemini – Thinking | 100% AI
✅ |
 |
| DeepSeek – DeepThink | 100% AI
✅ |
 |
| Perplexity – Free Model | 100% AI
✅ |
 |
| Grok – Auto | 99% AI
✅ |
 |
| Meta | 85% AI
✅ |
 |
Test #2: Phrasly.AI vs. Humanizers
This stage of our analysis tested Phrasly.AI against text that had been written by an LLM and then humanized to remove AI writing patterns. We took the text generated by Meta in Test #1, ran it through eight humanizers, and scanned the revised versions for AI.
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| AI Humanizer | Test Result | Proof |
| Humanize.ai (humanized text) |
41% AI
🟡 |
 |
| StealthGPT (humanized text) |
44% AI
🟡 |
 |
| WriteHuman.ai (humanized text) |
5% AI
❌ |
 |
| Undetectable.ai (humanized text) |
93% AI
✅ |
 |
| StealthWriter.ai (humanized text) |
9% AI
❌ |
 |
| WalterWrites.ai (humanized text) |
7% AI
❌ |
 |
| Grammarly (humanized text) |
90% AI
✅ |
 |
| QuillBot (humanized text) |
55% AI
🟡 |
 |
Test #3: False-Positives + Plagiarism
Our final test assessed whether Phrasly.AI would produce false positives, meaning it would incorrectly detect AI in text written by humans. We also took this opportunity to test the platform’s plagiarism checker.
Both the false-positive and plagiarism tests were performed using 10 texts that were not generated by AI, including interview transcripts, famous literary works, and news articles.
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| Article URL | Test Result | AI Detector | Plagiarism |
| A Tale of Two Cities (excerpt) | 26% Human, 100% Plagiarism
❌ |
 |
 |
| The Hill (opinion piece) | 95% Human, 100% Plagiarism
✅ |
 |
 |
| Fox Business (article) | 28% Human, 97% Plagiarism
❌ |
 |
 |
| Nobel Prize (interview) | 98% Human, 99% Plagiarism
✅ |
 |
 |
| Wikipedia (“bass guitar”) | 78% Human, 97% Plagiarism
✅ |
 |
 |
| arXiv (research paper) | 89% Human, 100% Plagiarism
✅ |
 |
 |
| Encyclopedia (biography) | 55% Human, 96% Plagiarism
🟡 |
 |
 |
| The White House (presidential message) | 46% Human, 100% Plagiarism
🟡 |
 |
 |
| SciTechDaily (article) | 94% Human, 96% Plagiarism
✅ |
 |
 |
| Archives.org (speech) | 17% Human, 100% Plagiarism
❌ |
 |
 |
Is Phrasly.AI Accurate?
User reviews on Trustpilot show that Phrasly.AI provides accurate AI detection, though some reviewers reported instances where human-written content was mislabeled as AI-generated.
Overall, Phrasly.AI maintains an excellent user rating of 4.7, with 91% of all reviews receiving 5 stars.
Frequently Asked Questions
Do unused words carry over?
No, words must be used within the billing cycle. Any remaining balance resets when the next cycle begins.[3]
Are sentence-by-sentence breakdowns provided?
Yes, detection reports highlight all sentences that appear AI-generated and show the percentages of human and AI-written text (see image).
Is document scanning included?
Yes, document scanning is supported for TXT, PDF, and DOCX files, provided they are 50 MB or smaller.
Is image scanning provided?
No, none of Phrasly.AI’s products provide image scanning; only text and uploaded documents can be checked for AI or plagiarism.
Are reports shareable?
It depends. Plagiarism results can be downloaded as PDFs and shared, but AI detection reports cannot.
Does Phrasly.AI provide certifications?
No, reports do not come with any certifications verifying the accuracy of AI detection or plagiarism results.
Are AI detections used for internal training?
No, the content users enter is not used to train AI models.[4]