Shortlist by what you need
Start here if you know why you are leaving Undetectable AI.
Want the closest match?
StealthWriterMost similar to Undetectable AI in what it does, its category and its price.
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SmodinHas a free plan, rated 4.2 out of 5.
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MyDetectorFrom $6.99/mo, the lowest starting price here.
Visit (opens MyDetector in a new tab)Want the best rated?
Netus AIRated 3.6 out of 5 in our review, against 3.2 for Undetectable AI.
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At a glance
Green means better than Undetectable AI, red means worse. Prices are starting prices per month.
| Tool | Our rating | Starts at | Free plan | Best for | Compare |
|---|---|---|---|---|---|
 Undetectable AIBaseline | 3.2 | Free | Yes | Detects AI content across text, image, audio and video, and also rewrites text to evade detection. | |
| StealthWriter | 2.9−0.3 | $20/mo | Yes | Rewrites AI-generated text to defeat AI detectors, and ships a detector to check the result. | vs Undetectable AI |
| Netus AI | 3.6+0.4 | $30/mo | Yes | AI paraphrasing and humanizing tool that rewrites text to read as human-written and pass AI detection. | vs Undetectable AI |
| MyDetector | 2.4−0.8 | $6.99/mo | Yes | Sells the AI detector and the tool for defeating it from the same navigation bar. | vs Undetectable AI |
 GPTinf | 3.5+0.3 | $19/mo | No | A paraphrasing engine that rewrites AI-generated text to read as human-written. | vs Undetectable AI |
 Plagiarisma | 3.2Same | Free | Yes | Free online plagiarism checker with an AI content detector, an AI paraphrasing tool and an AI essay writer. | vs Undetectable AI |
 JustDone | 2.7−0.5 | Not listed | No | Eleven student writing tools, two of which cancel each other out. | vs Undetectable AI |
| Smodin | 4.2+1.0 | $10/mo | Yes | A grab-bag of writing utilities rather than one flagship feature | vs Undetectable AI |
 ZeroGPT | 3.5+0.3 | Free | Yes | AI detection across text, image and video, with sentence-level highlighting. | vs Undetectable AI |
The alternatives in detail
In order of how closely each one matches Undetectable AI.
StealthWriter
2.9$20/mo
vs Undetectable AI−0.3
Rewrites AI-generated text to defeat AI detectors, and ships a detector to check the result.
- AI humanizer with light, medium and aggressive modes
- Bundled AI detector to verify the output
- Deep Scan sentence-by-sentence analysis
Sentence-level control rather than one blanket rewrite
Its purpose is defeating detection, and students are the first audience named
Netus AI
3.6$30/mo
vs Undetectable AI+0.4
AI paraphrasing and humanizing tool that rewrites text to read as human-written and pass AI detection.
- AI Detection Bypasser that rewrites flagged text to read as human-written
- Paraphrasing engine covering 36 languages with adjustable tone and style
- Built-in AI content detector for checking text before publishing
Free Starter tier lets new users test output quality before paying
Reported team size is tiny (around one employee), raising questions about long-term support capacity
MyDetector
2.4$6.99/mo
vs Undetectable AI−0.8
Sells the AI detector and the tool for defeating it from the same navigation bar.
- Free AI detection on pasted or uploaded content
- Detection report with per-section breakdown
- Sample texts including a mixed AI-and-human case
Provides a mixed AI-and-human sample, the realistic disputed case
Sells an AI Humanizer to defeat the detector it also sells
GPTinf
3.5$19/mo
vs Undetectable AI+0.3
A paraphrasing engine that rewrites AI-generated text to read as human-written.
- Rewrites AI-generated text using a non-AI algorithm targeting perplexity and burstiness
- Eight distinct rewrite modes for different tone and style outcomes
- Built-in AI detector that scores text for AI-pattern probability
Addresses detection and rewriting in one interface instead of two separate tools
Independent tests have shown it failing to bypass detectors like GPTZero in some cases
Plagiarisma
3.2Free
vs Undetectable AISame
Free online plagiarism checker with an AI content detector, an AI paraphrasing tool and an AI essay writer.
- Plagiarism check against web sources, books and academic papers
- 190+ languages and uploads in a dozen file formats
- AI Content Detector for machine-written text
Free to use, with no paid plan shown on the pages reviewed
No model, limits or accuracy figures are given for the AI tools
JustDone
2.7Not listed
vs Undetectable AI−0.5
Eleven student writing tools, two of which cancel each other out.
- Plagiarism checker and citation generator
- Summariser, paraphraser and grammar checker
- AI chat that reads PDFs and websites
Most of the toolkit is ordinary, useful study software
Ships an AI humanizer beside an AI detector, defeating both
Smodin
4.2$10/mo
vs Undetectable AI+1.0
A grab-bag of writing utilities rather than one flagship feature.
- Multi-mode paraphrasing tool
- AI content detector
- Plagiarism checker
Covers many unrelated writing tasks in one account
No single feature matches dedicated specialist tools
ZeroGPT
3.5Free
vs Undetectable AI+0.3
AI detection across text, image and video, with sentence-level highlighting.
- AI text detection with sentence-level highlighting
- DeepAnalyse multi-stage detection method
- AI image and video detectors
Sentence highlighting supports a conversation rather than an accusation
AI detection has a documented false-positive problem on non-native English
FAQ
Questions people ask
Is Undetectable AI free?
Undetectable AI has a free plan.
What is the best free alternative to Undetectable AI?
Smodin is the highest-rated alternative here with a free plan (4.2 out of 5). Other free options: Netus AI, ZeroGPT, Plagiarisma.
What is the cheapest alternative to Undetectable AI?
Among paid plans, MyDetector has the lowest starting price (from $6.99/mo). If you need it free, start with Smodin.
How did you pick these alternatives?
We match tools on what they do, their category and their price, using the details in our directory. Ratings come from our reviews and reader reviews.