The growth of AI content has created a new challenge: how to transform AI-written texts into something that sounds like real human writing.
We've tested over 30 AI humanizer tools, running each one through the same test content, and discovered which tools work best by using both GPTZero.
This guide explains the 10 best AI humanizers available in 2025, including real bypass rates and prices.
AI humanizers are software tools that change AI-generated content into text that sounds more natural. They do this by getting rid of repetitive patterns, using simpler synonyms for complicated words, and adding more variety to the writing.
Some examples are Overchat AI Humanizer, Undetectable AI, StealthGPT, and QuillBot.
The text is now simpler.
Overchat AI humanizer focuses on keeping your original meaning while making text sound natural. It works by breaking up long sentences and replacing common AI phrases.
Bypass Rate:
✅ GPTZero: 2%
Pros & Cons:
✅ Very high bypass rate
✅ Doesn't change your facts or main points
✅ Results in under 10 seconds
❌ Slightly more complicated interface
Pricing:
Free: Up to 3,000 characters/day
Pro: $4.99/week (unlimited words)
StealthGPT is a simple tool that creates shorter, more natural text. Just paste your AI content (there’s a 350-word limit) and it'll quickly transform it.
Bypass Rate:
✅ GPTZero: 2% AI probability
Pros & Cons:
✅ One of the lowest AI detection rates in testing
✅ Text feels genuinely human-written
✅ Simple to use
❌ No built-in AI detection
❌ Can't adjust style or formality
Pricing:
Humanize AI converts AI content for free without requiring an account. It highlights changes in orange and unchanged parts in blue so you can see exactly what was modified.
Bypass Rate:
✅ GPTZero: 2% AI probability
Pros & Cons:
✅ Standard, Academic, Simple, Formal, and Informal modes
✅ Ultra Run feature for maximum AI detection avoidance
✅ Shows all changes: Orange for edits, blue for original text
❌ No built-in AI detector
❌ Only 200 words per day on free plan
Pricing:
Quillbot is a paraphrasing tool used by 4.3 million users. While not specifically an AI humanizer, it can transform AI text into easy-to-understand content.
Bypass Rate:
✅ GPTZero: 2% AI probability
Pros & Cons:
✅ Makes text easier to understand
✅ Choose from various language options
✅ Over 4.3 million users globally
❌ Very limited free version with only 125 words at a time
❌ Only 2 free modes
Pricing:
Writesonic's free humanizer lets you select from 23 languages and 13+ tones like engaging, bold, confident, friendly, or professional. Limited to 200 words per use.
Bypass Rate:
✅ GPTZero: 5% AI probability
Pros & Cons:
✅ You can choose from 13+ different writing styles
✅ Works in 23 languages
✅ Good for short content - Perfect for social media posts
❌ No built-in AI detector
❌ Takes only 200 words at a time
❌ Output feels human-like but still somewhat generic
Pricing:
Undetectable AI checks your content against multiple AI detectors automatically including GPTZero, OpenAI, QuillBot, and Copyleaks. Has a 15,000 character input limit.
Bypass Rate:
✅ GPTZero: 7% AI probability
Pros & Cons:
✅ Built-in AI detection
✅ Customization options — choose readability level, purpose, and output preference
✅ 15,000 characters for longer documents
❌ Text doesn't feel very human-like
❌ We found multiple punctuation errors in testing
❌ Only 250 words free (1 word = 1 credit)
Pricing:
Hix Bypass is trained on human-written content and uses 4 different modes: Fast, Balanced, Aggressive, and Latest. It checks output with 7 AI detectors including GPTZero and Copyleaks.
Bypass Rate:
✅ 0% AI detected
Built-in checking with 7 detectors
Pros & Cons:
✅ Passed with 0% AI score
✅ Multiple modes
✅ Shows detection results
❌ Output has typos, especially in Aggressive and Latest modes
❌ Very limited free plan - only 300 words total and only 125 words at a time
❌ Quality varies by mode, Balanced works best
Pricing:
Humanize AI Text offers personalization settings where you can create a persona and define your audience. It also has Goals settings for tone, clarity, and engagement level.
Bypass Rate:
✅ GPTZero: 7% AI probability
Pros & Cons:
✅ You can create custom personas and define audiences
✅ Multiple modes: Shorten, Expand, Simplify, Improve writing
✅ Adjust tone, clarity, focus, and language complexity
❌ Makes text longer
❌ No built-in AI detection
❌ Enhanced mode costs extra
Pricing:
BypassGPT is trusted by TechRadar, Business Insider, and PC World. It has a Daily Check-In system where you earn 20 free words every day just by logging in.
Bypass Rate:
❌ GPTZero: 50% AI detected (Failed)
❌ 4 detectors showed 100% AI (Failed)
Pros & Cons:
✅ Checks multiple detectors
✅ Get 20 words each day you log in
❌ Poor bypass rate
❌ Only 80 words at a time on free plan
❌ Makes text readable but still detectable
Pricing:
AI Humanizer by Ask Your PDF generates 5 different versions of your text so you can choose the most realistic one. Has a high 2000-word input limit on the free plan.
Bypass Rate:
❌ GPTZero: 62% AI probability (Failed)
Pros & Cons:
✅ 5 text versions
✅ High word limit
✅ Simple interface
❌ High AI detection rate
❌ Limited customization
❌ No advanced features
Pricing:
AI humanizers are tools that change AI-generated text to sound more natural and like it was written by a person. They change the structure of sentences, the words used, and the way the writing is arranged to make it seem like it was not written by a computer. Some examples of these tools are Undetectable AI, StealthGPT, and QuillBot.
OverchatAI is one of the best AI humanizers overall, with a 2% AI score on GPTZero. It keeps your original meaning while getting around most AI detectors. StealthGPT and Humanize AI also perform well, both achieving only 2% AI probability on GPTZero.
Several tools offer free plans with daily or weekly limits. Overchat AI offers 3000 free characters daily, StealthGPT allows one free use every seven days. Humanize AI provides 200 words a day. QuillBot allows 125 words at a time. AI Humanizer by Ask Your PDF has the most generous free plan, allowing 2000 words per use.
AI humanizers only make small changes, like swapping words and changing sentence structure. They can't add real human insights, experiences, or creativity. The output often has errors and sounds robotic. Most importantly, they're just adding another algorithmic layer on top of AI content, which means you'll still need to manually edit for quality.
These tools use different methods to change text. They change sentence structures by removing commas and adding words like "which" and "while" to connect the sentences. They replace common AI words with more varied ones. Some tools add conversational phrases or adjust paragraph patterns. The goal is to make the patterns that AI detectors look for more varied.
After testing 30+ AI humanizers, only three tools consistently bypass AI detection:
Most other tools either don't work at all or produce error-filled text that still sounds robotic.
If you're a free user, the best options for you are Overchat AI, Humanize AI, or Ask Your PDF.
However, remember that no AI humanizer can create content that is completely undetectable. They only make surface-level changes, which might fool basic detectors like GPTZero, but fail against more sophisticated tools like Copyleaks. You'll always need to manually edit the output, add personal insights, and verify facts to create content that feels human-made.
