StealthWriter and Undetectable AI both rewrite AI-generated text to read naturally and dodge AI detectors — but they differ on guarantees and depth. Undetectable AI backs its humanizer with a money-back guarantee if output is still flagged, while StealthWriter includes a free built-in AI Detector with sentence-by-sentence Deep Scan so you can check before you rewrite. Here's which one fits your workflow.
If you want a money-back guarantee on detection bypass and a platform that also detects AI images, voice, and video, go with Undetectable AI. If you want a more generous free plan (10 humanizations/day, no card needed) plus a free built-in detector with Deep Scan to check your text before and after, go with StealthWriter.
| Tool | Starting Price | Free Plan | Best Feature | Best For |
|---|---|---|---|---|
| StealthWriter | $20/mo (Starter) | Yes — 10 humanizations/day, no card | Deep Scan flags sentence-by-sentence what still reads as AI | Writers who want to check before and after for free |
| Undetectable AI | $5/mo (10K words) | 250-word trial only | Money-back guarantee if output is still flagged | Teams that want a bypass guarantee across text, image, and video |
Price: Free (10 humanizations/day) → $20/mo Starter → $50/mo Plus → $100/mo Pro → $400/mo Scale. Best for: Writers, marketers, copywriters, and researchers who draft with AI and want the output to read naturally, with clear phrasing and no generic AI tone.
Price: 250-word free trial → $5/mo (10K words) → $9.50/mo (20K) → $15.75/mo (35K) → $21.25/mo (50K) → custom Business. Best for: Content marketers, non-native English writers, and teams who need AI-assisted writing to read naturally and pass AI-detection checks used by publishers, platforms, or institutions.
Both tools rewrite AI text to read more naturally, but they signal confidence differently. Undetectable AI backs its humanizer with an explicit money-back guarantee if the rewritten text is still flagged by AI detectors — a stronger commitment on paper. StealthWriter doesn't offer a guarantee, but lets you pick a rewrite intensity (light, medium, aggressive) and then re-scan the result yourself with its own built-in detector before you commit to using it.
This is StealthWriter's clearest edge: its Deep Scan feature breaks a scanned document down sentence-by-sentence with color-coded highlights, showing exactly which parts still read as AI-generated so you know what to fix. Undetectable AI also bundles an AI detector, but it extends further — covering AI-generated images, voice, and video/deepfakes — useful if you need to verify more than just text.
StealthWriter's free plan is the more usable starting point: 10 humanizations and 10 scans per day with no credit card required, versus Undetectable AI's one-time 250-word trial. Once you're paying, Undetectable AI is cheaper at the low end ($5/mo for 10,000 words), while StealthWriter's plans scale from $20/mo up to $400/mo for high-volume teams.
Undetectable AI packs in more adjacent tools — a paraphraser, AI essay writer, plagiarism checker, and even a watermark remover — positioning itself as a broader writing-assistance suite. StealthWriter stays more focused on the humanize-and-detect loop itself, which keeps its interface simpler if that's all you need.
Pick StealthWriter if you want to test extensively for free and like being able to scan and re-check your own text with Deep Scan before publishing. Pick Undetectable AI if you want the reassurance of a money-back guarantee and may also need to check AI-generated images or video, not just text.
StealthWriter and Undetectable AI aren't the only options. HumanizeAI bundles a humanizer with an AI content optimizer and grammar checker, and processes text from any AI source (ChatGPT, Claude, Gemini) with a genuine free plan of 1,500 words/month — worth a look if neither of the above is the right fit.
Is StealthWriter or Undetectable AI better for beginners? StealthWriter is easier to try first since its free plan (10 humanizations/day, no card required) is more generous than Undetectable AI's one-time 250-word trial.
Which tool guarantees AI detectors won't flag the output? Undetectable AI offers a money-back guarantee if humanized text is still flagged by AI detectors; StealthWriter doesn't offer a formal guarantee but includes a free detector to self-check first.
Can either tool detect AI-generated images or video, not just text? Yes — Undetectable AI detects AI-generated images, voice, and video/deepfakes in addition to text. StealthWriter's detector is text-focused.
Is using an AI humanizer against the rules? It depends on context — using AI humanizers to bypass academic, platform, or publisher detection policies can violate those policies even if the tool itself is legal to use. Check your institution's or platform's specific rules first.
Thomas
Founder
Thomas is the founder of AIPick.info and an avid AI enthusiast dedicated to testing and reviewing the latest tools. He believes technology should make life easier and more enjoyable for everyone. Beyond providing practical reviews, Thomas aims to build an uplifting space where AI feels accessible, delivering insights with energy, positivity, and a commitment to helping others innovate with a smile.
