AI detectors are getting smarter, and the last thing any writer wants is to get flagged for using “robotic” content, especially if you’re working with clients, publishers, or SEO platforms that demand authenticity.
That’s precisely where AI humanizers come in. These tools help you rewrite or refine AI-generated text to read more naturally, like something written by an actual human (not a predictive language model). But not all of them work equally well.
At DemandSage, we personally tested over a dozen AI humanizers to see which ones are truly worth your time and money. We reviewed 10+ AI humanizer tools, including free and paid ones that bypass the majority of AI detectors.
10 Best AI Humanizers Of 2025 (Tested & Reviewed)
Here’s the final list of the top 10 AI humanizers. We have checked and tried ourselves and found them to be the right option for writers and bloggers:
| AI Humanizer | Price | Free Trial |
|---|---|---|
| Undetectable AI | $19/month (20K words) | Yes (300 words) |
| Surfer SEO (Humanizer) | $99/month (50K words) | Yes (300 words) |
| Hix AI | From $14.99/month | Yes |
| WriteHuman | $18/month | Yes |
| QuillBot | $4.17/month | Free plan available |
| Stealth Writer | $20/month | Yes |
| Uncheck AI | $12.99/month | Yes |
| BypassGPT | $35/month (30K words) | Yes |
| StealthGPT | $24.99/month | Yes (300 words) |
| Scribbr | $4.17/month | Yes (200 words) |
Now, let’s check out what an AI humanizer is and how they work.
What is an AI Humanizer And Why Do You Need It?
An AI humanizer is a software tool or service that takes AI-written text and rephrases it to mimic natural human writing. It “humanizes” content by varying word choice, adjusting tone, and correcting patterns common in AI text.
These tools use advanced algorithms to smooth out passive voice, add idiomatic phrases, and break up repetitive structures—basically removing the robotic markers of AI writing.
You might need an AI humanizer for two big reasons: SEO and readability.
- For SEO, Google has become savvy at spotting AI-generated content and often prefers pages with authentic human engagement. An AI humanizer can help your article pass AI-detector tests and avoid any penalties for sounding too machine-generated.
- For writers and freelancers, it’s equally about quality: even if AI generates a first draft, a humanizer helps the final copy flow naturally and connect with readers. Think of it as a post-processing step – not cheating, but polishing.
When editing AI text for clarity or adding personality, using a humanizer is typically fine (especially if you later review and adjust the output yourself). Remember the ethics: it’s best used to enhance your work, not to sneakily twist someone else’s writing as your own.
1. Undetectable AI
Undetectable AI is a dual-purpose platform: a leading AI content detector and an AI humanizer. Its marketing highlights that it “makes AI-generated content more human-like” to safely rank on Google.
In practice, you paste your AI text into Undetectable AI and hit “Humanize.” The tool analyzes the content across multiple AI detectors and rewrites it to remove automated language patterns, aiming for a “100% human score” on detectors.
Key Features:
- Multi-tool suite: Includes both an AI content checker and the humanizer. You can scan your text with many detectors at once, then humanize in one click.
- AI Detector integration: Flags AI-generated segments and lets you selectively humanize those parts.
- Editing modes: Offers options to adjust tone or keep meaning intact while changing wording.
- Supported formats: Works on articles, essays, emails, and any text you paste.
Pros:
- Very straightforward and fast for one-click humanizing.
- Integrates AI detection so you can verify the score before/after.
- Well-known (Forbes dubbed its AI checker #1).
- Good for Google-focused writers – “insurance policy” against being flagged
Cons:
- The 20K words limit may be low if you produce a lot each month.
- Some advanced tweaks or voice customizations are limited compared to larger suites.
- The humanizer output can occasionally still sound formulaic, so manual edits might be needed.
Pricing: Plans start at $19/month for 20,000 words per month (billed monthly). A free trial gives you about 300 words to test the humanizer. They also offer a yearly plan (~$5/mo for 10K words) if you pay annually.
2. Surfer SEO (AI Humanizer)
Surfer SEO is an established AI SEO tool that recently added an AI Humanizer to its set of features. It’s aimed at content creators who already use Surfer’s Content Editor or AI Writer.
You paste your AI draft into the humanizer, and Surfer rewrites it to read as though a human wrote it, all while preserving your keywords and SEO structure. In short, it smooths out AI awkwardness so you can “rank on Google” with AI-assisted content.
Check out our detailed Surfer SEO review to know more about its tools and capabilities.
Key Features:
- Integrated SEO context: Because it’s part of Surfer’s suite, the humanizer takes into account SEO guidelines.
- Unlimited detection: You can check any length of text for AI content (the detector is unlimited even on free accounts.
- Word limits: Free users get 500–1000 words of humanizer per month; paid users get up to 50,000 words per month.
- Custom Voice: Surfer added a feature to “teach” the humanizer your personal tone of voice for even more tailored rewrites.
Pros:
- Produces high-quality, natural-sounding text especially suited for SEO content.
- Comes with Surfer’s built-in AI detector – you can humanize and re-check instantly.
- Good customization (tone settings, multiple language support in Pro).
Cons:
- The cost is relatively high if you only need the humanizer.
- Locked behind Surfer’s ecosystem – not a standalone, so you need a Surfer account.
- Limited to English for now (though more languages are planned).
Pricing: It requires a Surfer subscription. Their Essential plan (50K humanizer words per month) runs around $99/month ($79 if billed annually). They offer a free web version with about 300–500 words per month for visitors.
3. Hix AI (HIX Bypass)
HIX AI offers the HIX Bypass tool, which is marketed as a way to “humanize your AI text” and beat detectors. It boasts that it can turn ChatGPT or GPT-4 output into “100% human score content”.
Essentially, it’s an anti-AI-detection rewriter: you paste in AI content, and it uses different modes (Fast, Balanced, Aggressive) to paraphrase the text. The site stresses that it can evade basic detectors and even advanced ones like Winston AI or Originality AI.
Key Features:
- Multiple modes: Fast, Balanced, and Aggressive rewriting to control how much rewording happens.
- Built-in detectors: It includes its own checks for ChatGPT, Claude, Gemini etc., so you can preview a detection score.
- Watermark removal: Claimed ability to remove ChatGPT’s watermark signals.
- Multi-language support: Handles 50+ languages.
- API access: (For developers to integrate HIX into apps.)
Pros:
- Very focused on beating detectors; multiple modes give flexibility.
- Large word caps on higher plans (up to 50,000 in Pro and unlimited words in the Bypass Unlimited plan).
- Useful extras like an integrated plagiarism-free claim and GDPR-friendly privacy.
Cons:
- In testing, the rewrites can occasionally feel off or over-complicated (some users report glitchy output).
- Originality.ai found that HIX’s humanizer didn’t significantly drop AI scores in their tests
- The pricing is a bit confusing (advertised plans fluctuate between the website and third-party sites).
Pricing: HIX Bypass has tiered plans. Basic starts at around $14.99/month (for 5,000 words/month), and the Unlimited plan is at $59.99/month. A free version or trial is available (with low word limits) so you can test the humanizer on a few samples.
4. WriteHuman
WriteHuman is a straightforward AI humanizer tool on the web. Its site proclaims it transforms AI text into undetectable, human-like content and plugs itself as working with Turnitin, GPTZero, Originality, etc.
In practice, you copy your text, click “Write Human,” and it produces a rewritten version that aims to blend in. WriteHuman also includes a separate AI Detector, so you can check how much of your content looks human or AI.
Key Features:
- Humanizer: A one-click converter that rephrases AI content to sound more natural.
- AI Detector: A free checker to measure AI vs human score.
- Bracket preserving: You can put words in brackets to tell WriteHuman not to change them.
- Privacy focus: Writes about “maintaining anonymity online” and eliminating AI tracking.
Pros:
- Budget-friendly: One of the cheaper options with a real free version.
- Works on any AI text (ChatGPT, Bard, etc.).
- Simple interface, excellent for quick fixes.
- According to reviews, it does decently well smoothing out AI phrasing (especially with a second pass).
Cons:
- The output isn’t always perfect; you may need to tweak it.
- The company is smaller/less-known, so customer support and updates may be limited.
- Some user feedback suggests it occasionally leaves minor “AI-ish” tics.
Pricing: WriteHuman’s basic paid plan is $18/month, which is very affordable. They offer a free trial and even a free tier with limited usage (200 words per month). The paid plan increases word limits and adds features like multiple content modes.
5. QuillBot
QuillBot is a popular AI-powered writing assistant best known for its paraphrasing and grammar tools. Though not built solely as an “AI humanizer,” you can use QuillBot’s Paraphraser in Humanize mode to accomplish the same effect.
Essentially, it replaces words and restructures sentences to make text sound more fluent. QuillBot also provides grammar checks, summarization, and even an AI Detector on its site, making it a Swiss Army knife for writers.
Key Features:
- Paraphrasing in multiple modes: Choose from Standard, Fluency, or their new “Humanize” modes to rewrite text.
- Grammar checker: Spelling and grammar fixes that polish the output.
- Summarizer: Quickly shrink down AI text into concise summaries.
- Tone & Customization: You can set synonyms and freeze words to keep certain terms.
- AI Detector: Free checker (1250 word limit) to test your content.
Pros:
- Very versatile: great for paraphrasing, summarizing, and grammar, all in one tool.
- Trusted and frequently updated – a proven brand.
- Has a free plan and generous trial, which is rare in this niche.
- Easy-to-use interface.
Cons:
- Because it’s general-purpose, it sometimes changes meaning more than a specialized humanizer would.
- The free mode only humanizes a small chunk at a time.
- Paraphrased content occasionally needs review for nuance or tone drift.
Pricing: QuillBot has a free tier (up to 125 words in the paraphraser at a time) and a premium plan. The monthly plan is about $4.17/month (if you pay yearly).
6. Stealth Writer
StealthWriter (by AiVantage) is marketed as an “SEO tool” that humanizes AI content and gets a 100% human score.
On its homepage, it promises to convert AI outputs into “human-like content” and claims it can be verified as such by detectors like Originality.ai, GPTZero, Turnitin, etc. Apparently, it’s another rewriting engine with an emphasis on passing AI checks.
Key Features:
- Built-in AI Detector: You can check your content with their detector before or after humanizing.
- Ninja & Ghost models: Proprietary rewriting models named “Ninja” and “Ghost” for different styles.
- Multi-language: Humanizes English (ChatGPT) as well as Spanish, French, German (ChatGPT outputs).
- Error correction: Emphasizes fixing typos or odd phrasing while preserving meaning.
Pros:
- Simple and fast: one-click “Humanize” with decent results.
- Claims strong detector evasion (supports all major detectors).
- Affordable entry price if you only need light use.
Cons:
- Output quality is mixed; you may find it helps, but it isn’t flawless (some rewrites can be a bit awkward).
- The free tier is pretty limited in use.
- As with similar tools, there’s no guarantee it will fool every AI-checker.
Pricing: StealthWriter’s pricing is $20/month for the Basic plan (400 words per request, all detectors). Higher tiers (Standard $35, Premium $50) offer more words per request and higher monthly limits. They also have a free plan with a generous 5,000 words/day limit, but only 300 words per request and fewer features.
7. Uncheck AI
Uncheck AI (by Tenorshare) is a humanizer designed for more authentic writing. Its landing page describes it as a tool that “adjusts tone, improves readability, and ensures content flows smoothly”.
It highlights features like contextual analysis and tone adjustment to make text sound human. It explicitly claims to help you “bypass AI detection” for tools like Turnitin, GPTZero, Originality, etc.
Key Features:
- Contextual analysis: The AI understands the meaning of your text to give relevant suggestions.
- Tone adjustment: Rewrites sentences and word choices to add a human-like tone.
- Plagiarism checking: Integrated scan to keep content unique.
- Multilingual: Works in many languages.
Pros:
- Focuses on polish and style, not just random spinning.
- Supports multiple languages for global use.
- Not just a rewriter – also checks plagiarism and integrates context.
Cons:
- Testing suggests like other humanizers, it doesn’t truly fool all detectors every time.
- Premium pricing is low, but details on limits are a bit vague.
- You must trust their promises of quality; independent reviews are scarce.
Pricing: Uncheck AI offers a free basic version with limited humanization. For heavy users, they have premium plans starting from $12.99/month, unlocking full features. The free version lets you try it on shorter passages; upgrading gives you faster processing and more words at once.
8. BypassGPT
BypassGPT is an AI humanizer billed as a “one-click AI to human” converter. It claims to make your AI text achieve “100% human scores” on detectors like GPTZero and Originality.ai.
After pasting your text, hit “Humanize,” and it will rewrite the content to be more creative and authentic. The site also hypes plagiarism-free outputs and SEO-friendliness as perks.
Key Features:
- Creative rewriting: Focus on adding storytelling flair and authenticity.
- Detector claims: Advertised as having beaten popular AI detectors (list on the site).
- Built-in tools: They bundle in an AI Detector and Plagiarism Remover on the site.
- Modes: Offers Fast/Creative/Enhanced rewriting modes.
Pros:
- Targets writers and students explicitly, easy to use.
- Covers all basic needs: rewrites for SEO, adds creativity, checks detectors.
- Offers a trial of sorts with free word credit.
Cons:
- Reviewers note that the rewrites can have errors or choppiness.
- The pricing structure is more expensive than some alternatives for large volumes.
- As with others, it’s not magic – it simplifies AI text but won’t guarantee invisibility under every test.
Pricing: BypassGPT has a limited free plan (150 words/month). Premium plans are higher, depending on words and billing period (Pro plan 30K words for $15/mo yearly, $35/mo monthly). An “Unlimited” plan is even pricier ( $39/mo monthly) for no word cap.
9. StealthGPT
StealthGPT (from the creators of Undetectable.ai) is a full AI suite that includes an AI Humanizer among many features. It’s pitched as a platform for creating unlimited, undetectable content.
Beyond the humanizer, it offers a study simulator, Chat with PDF, an SEO writer, a Chrome extension, etc. The idea is to keep your whole workflow “stealthy.” You can use StealthGPT’s humanizer to convert AI text into a more natural form, then store and manage it all in one place.
Key Features:
- AI Humanizer: One-click rewriting to humanize AI text.
- AI Detector: Integrated to test content both before and after.
- Language options: Pro plans support 100+ languages for the humanizer.
- Other tools: Stealth Writer (to batch-generate stealth content), PDF Q&A, intext citations, etc.
- Apps & Extensions: Offers an iOS app and Chrome extension to humanize on the fly.
Pros:
- Much more than just a humanizer – great if you want one platform for writing and detection.
- Powerful features and lots of customization (languages, add-ons).
- Good for teams (has collaboration and API options).
Cons:
- It can be overkill if you only need a simple humanizer.
- The price is high compared to standalone tools.
- The extra features have learning curves.
Pricing: StealthGPT’s Essential plan (annual billing) is $24.99/month and includes unlimited words and the AI Humanizer. Their Pro ($34.99/mo) adds 100+ language support and “Extreme Stealth Mode”. There’s also a Business level and higher Enterprise plans for large needs. They often advertise a trial and have a 4.0/5 Trustpilot rating.
10. Scribbr
Scribbr is best known as an academic proofreading and plagiarism-check site, and they added an AI Humanizer feature. Scribbr’s humanizer doesn’t aim to completely hide AI content; instead, it polishes AI text by rephrasing unnatural phrases.
The tool looks at your text and suggests more natural ways to say the same thing, smoothing out overly formal or repetitive patterns. It explicitly states that its goal is writing quality (making text sound natural and authentically yours) rather than fooling detectors.
Key Features:
- Phrase suggestion: Automatically spots AI-like wording (e.g., “It is important to note…”) and offers simpler alternatives.
- Focus on clarity: Improves tone and vocabulary while keeping your original meaning.
- User-friendly: Web-based with a clean interface; great for quick fixes on essays, blog posts, and emails.
- Academic ethics: Unlike others, Scribbr doesn’t encourage evasion – they emphasize transparency and learning.
Pros:
- High-quality rewriting that genuinely improves readability.
- Great for non-native speakers or formal writing tasks.
- The AI detector on Scribbr (separate from the humanizer) is well-regarded in academic circles.
Cons:
- It’s not specifically built to bypass AI checkers; results can vary.
- You’re essentially paying for editing help rather than unlimited use.
Pricing: Scribbr is mainly available for a plagiarism checker, which charges per word. However, going for an AI humanizer will lead you to Quillbot pricing, as they are from the same parent company.
Is It Right To Use An AI Humanizer?
Using an AI humanizer can feel a bit like giving your AI draft a final editing pass. It isn’t fundamentally unethical. In many cases, it’s simply a way to refine your own content. For instance, if you write a blog post with AI and then use a humanizer to smooth out the tone, that’s comparable to having an assistant rewrite sentences for clarity.
Many recognized SEO experts suggest focusing on quality and originality regardless of how a draft was created. In fact, they point out that the only truly reliable way to beat AI detectors is to focus on unique style and writing quality. A humanizer can help you do that by removing awkward AI phrases.
That said, transparency is key. If you’re submitting work for a client or an academic assignment, consider telling them that you used AI plus editing.
Just remember that it shouldn’t replace your own voice and creativity. The best practice is to treat it like a smart editor: run your AI draft through it, then read the output yourself and tweak as needed.
Conclusion: Undetectable AI is One of The Best AI Humanizers Of 2025
AI humanizers have grown into powerful assistants for content creators. Among the tools we’ve covered, our top 3 recommendations are:
- Undetectable AI
- Surfer SEO (Humanizer)
- QuillBot
Each of these tools will help you produce more natural-sounding content. In our experience, they blend AI speed with a human touch best: Undetectable AI and Surfer SEO for their high-end rewriting capabilities and SEO focus, and QuillBot for its flexibility and user-friendliness.
Depending on your needs and budget, any of these can significantly improve your AI-assisted writing. You can get started with their available free plan or free trials.
