5 AI Humanizer and Detection Tools Compared (2026)

Five tools on AIPick tackle AI text: StealthGPT, StealthWriter, Undetectable AI, and HumanizeAI rewrite drafts to read more naturally, while Originality.ai checks writing for AI use and plagiarism. Prices run from free to $29.99/mo, and detector results vary by text, so treat every score as a signal, not proof.

At a Glance

Tool	Best for	Starting price	Free option
StealthGPT	Humanizer with built-in detector	$29.99/mo	None listed
StealthWriter	Rewrite levels plus a detector	$20/mo	Free plan, 10 per day
Undetectable AI	Humanizing and detection by word volume	$5/mo (annual)	250-word trial
HumanizeAI	Humanizing text from any AI source	$14/mo	Free plan, 300 words
Originality.ai	AI detection and plagiarism checks	$12.95/mo	Free plan, 3 scans a day

StealthGPT: Humanizer Plus Detector

StealthGPT rewrites AI text for natural tone and sentence variety, checks it with a built-in detector, and supports 100+ languages.

Quick Review — StealthGPT

• ✅ Pro: iOS app, Chrome extension, and MCP access for Claude and Cursor on every plan
• ❌ Con: No free plan listed, 1,000-word requests on Pro, and bypass claims come from the vendor
• 💰 Price: Pro $29.99/mo, Max $49.99/mo, Enterprise $179.99/mo
• 👤 Best for: Writers, students, and content teams

StealthWriter: Choose How Hard It Rewrites

StealthWriter humanizes AI text with a built-in detector and lets you pick light, medium, or aggressive rewrite levels.

Quick Review — StealthWriter

• ✅ Pro: Adjustable rewrite levels, and a free plan with no credit card
• ❌ Con: The free plan is capped at 10 humanizations and 10 scans a day, with a 1,000-word input limit
• 💰 Price: Free; Starter $20/mo, Plus $50/mo, Pro $100/mo, Scale $400/mo, with discounted annual billing
• 👤 Best for: Writers, marketers, copywriters, and researchers

Undetectable AI: Priced by Word Volume

Undetectable AI combines an AI detector with a humanizer and prices plans by monthly word allowance.

Quick Review — Undetectable AI

• ✅ Pro: A money-back guarantee if the humanized output is still flagged as AI-generated
• ❌ Con: The free trial is limited to 250 words
• 💰 Price: 10K words $5/mo, 20K $9.50/mo, 35K $15.75/mo, 50K $21.25/mo, billed annually
• 👤 Best for: Content marketers and non-native English writers

HumanizeAI: Works With Any AI Source

HumanizeAI rewrites text from ChatGPT, Claude, Gemini, and other AI tools into natural, human-sounding writing.

Quick Review — HumanizeAI

• ✅ Pro: Works with text from any AI source, with a free plan to test
• ❌ Con: The free plan is limited to 300 words per process
• 💰 Price: Free; Essential $14/mo, Standard $24/mo, Pro $59/mo
• 👤 Best for: Content creators, SEO professionals, researchers, and marketers

Originality.ai: The Checker

Originality.ai is an AI detector and plagiarism checker for content teams verifying outsourced writing, and it is kept current against the latest large language models.

Quick Review — Originality.ai

• ✅ Pro: Proven accuracy in third-party AI-detection studies
• ❌ Con: The free plan is capped at 2,000 words per scan and 3 scans a day
• 💰 Price: Free; Pro $12.95/mo (2,000 credits), Enterprise $136.58/mo (15,000 credits)
• 👤 Best for: Content teams, publishers, and agencies

Which Should You Try First?

• Want a free test? Start with StealthWriter or HumanizeAI.
• Paying by word volume? Undetectable AI's $5/mo plan is the cheapest entry.
• Checking freelancers' work? Use Originality.ai.
• Want detector and API access? Look at StealthGPT's higher tiers.

For comparisons, see our AI humanizer tools collection.

FAQ

Which of these tools has a free option? StealthWriter, HumanizeAI, and Originality.ai have free plans, and Undetectable AI has a 250-word trial. StealthGPT lists none.

Which is cheapest to start? Undetectable AI's 10K plan is $5/mo billed annually, followed by Originality.ai Pro at $12.95/mo.

Which one checks plagiarism? Originality.ai.

Can any tool guarantee text passes every detector? No. Detector results vary by text and tool, so review important content yourself.