Looking for the Best AI Content Detector Tools in 2025? After testing over 30+ tools myself, I discovered that only a few are truly reliable.
I still remember the first time one of my articles got flagged as AI-written.
I had spent a good three hours polishing it, mixing my own thoughts with AI-generated suggestions. But when I ran it through an AI detector (just out of curiosity), bam — “92% AI”.
That was my wake-up call.
Whether you’re a content writer, copywriter, blogger, or even a casual user experimenting with AI tools, chances are you’ve come across these so-called AI Content detectors. And let’s be honest — some of them are pretty bad. Others? Surprisingly accurate.
So, I decided to test the top AI content detection tools of 2025 and share my honest experience.
📄 Here’s Sorted List of Best AI Content Detectors Tools
1. Originality.ai
Very accurate, highlights AI parts, best for professionals. 9.5/10⭐️
2. Copyleaks AI Detector
Detailed reports, strong detection, reliable. 9.5/10⭐️
3. Merlin AI Detector
Fast, 100% score, good for quick checks. 9/10⭐️
4. ZeroGPT
Free, strong detection, some false positives. 9/10⭐️
5. NoteGPT
Smooth UI, accurate results, fast. 9/10⭐️
6. SurferSEO AI Detector
SEO-friendly tool, high detection rate. 8.5/10⭐️
7. Scribbr
Academic-focused, solid accuracy. 8.5/10⭐️
8. EduWriter AI Detector
Quick and high detection accuracy. 8.5/10⭐️
9. Phrasly AI
Clean interface, high AI score. 8.5/10⭐️
10. Writer.com AI Detector
Simple UI, quick checks, decent results. 8/10⭐️
11. Ryrob AI Detector
Good balance of speed and accuracy. 8/10⭐️
12. AIDetectors.io
Consistent results, easy to use. 8/10⭐️
13. Ahrefs AI Detector
Well-known brand, decent accuracy. 8/10⭐️
14. ISGen AI
Fast and functional, nice performance. 8/10⭐️
15. JustDone AI Detector
Reliable scoring, modern look. 7.5/10⭐️
16. Undetectable.ai (Detector Tool)
Better for detection than bypassing, works well. 7.5/10⭐️
17. Sapling AI Detector
Great for short content, highlights phrases. 7.5/10⭐️
18. Smodin AI Detector
Decent score, average speed. 7/10⭐️
19. ContentDetector.ai
Good results, a bit slow. 7/10⭐️
20. SurgeGraph AI Detector
Borderline score, still worth testing. 6.5/10⭐️
What Makes a Great AI Content Detector?
After testing over 30+ AI content detection tools myself, I can confidently say this — some are genuinely helpful, but a lot of them fail to catch even obvious AI writing.
If you’re serious about content quality, these Best AI Content Detector Tools in 2025 will give you the edge – especially when editing or publishing online.
So instead of relying on guesses or hype, I put together a personal checklist based on real-world results — what actually worked, and what completely missed the mark.
From all that testing, here’s what I believe truly separates a good AI detector from the rest.
- Accurate detection: especially against advanced AI models like GPT-4, Claude, and Gemini.
- Clear results: not just a score, but highlights that show exactly which parts were written by AI.
- Free or reasonably priced: no one wants to pay $20 just to check if their content sounds like AI.
- No sign-up required: the best tools let you paste your content and get results instantly.
- Decent word limit: should handle at least 1000 words without forcing you to break your content into chunks.
I Tested 30+ AI Detectors — Here’s What Actually Worked
I tested over 30+ different AI content detection tools using the same AI-generated content (written by ChatGPT) — just to see which ones are actually accurate and reliable.
But in this list, I’ve only included the tools that gave an AI detection score above 50%.
Some tools performed surprisingly well, catching the AI instantly. Others gave poor or completely inaccurate results — some didn’t even load properly.
So here are the tools that passed my personal benchmark (50%+ AI detection score):
| Best AI Content Detector Tools in 2025 | 📈 AI Detection Score |
| Originality.ai | 100% |
| Copyleaks | 100% |
| Merlin | 100% |
| ZeroGPT | 99.6% |
| NoteGPT | 99.6% |
| Scribbr | 94% |
| Phrasly AI | 94% |
| SurferSEO | 99% |
| EduWriter | 98% |
| Writer.com | 85% |
| Aidetectors.io | 85% |
| Ryrob AI Detector | 85% |
| Ahrefs AI Detector | 80% |
| ISGen AI | 80% |
| Sapling AI | 73.3% |
| JustDone | 75% |
| Undetectable.ai (Detector) | 76% |
| Smodin | 67% |
| ContentDetector.ai | 58.04% |
| SurgeGraph | 49% (borderline but worth mentioning) |
Best AI Content Detector Tools in 2025 (Reviewed One by One)
Here’s my breakdown of the top AI detectors I personally tried. I’ve included real feedback, not just marketing claims. Let’s go 👇
1. Originality.ai
Definitely one of the most accurate tools. It doesn’t just say “this is AI” — it actually highlights which parts of your content seem AI-written. That really helps if you’re editing and want to make it feel more human, line by line.
You get two free checks without needing an account, and it supports up to 750 words per scan.
💡Pro Tip: If you just want to check whether content is AI or not (without highlights), you can simply refresh the page and recheck. But be aware: after refreshing, the highlighted text disappears, so it’s best to copy results if you need them.
2. Copyleaks AI Detector
Copyleaks is a powerful detection tool used by many universities and businesses. It not only detects AI with impressive accuracy, but also provides sentence-level insights, showing which parts look suspicious — very useful for serious editing.
It supports modern models like GPT-4 and Gemini, and the results feel trustworthy overall.
3. Merlin AI Detector
Merlin surprised me with how fast and clean it is. You don’t need to create an account, and it immediately shows you whether your content is AI or human. The tool uses a simple color-based scale and feels very beginner-friendly.
But here’s the cool part — it gave a 100% AI score in my test, which puts it among the most accurate. However, there’s no sentence highlighting, so you can’t tell which parts of your text were flagged.
4. ZeroGPT
ZeroGPT is one of the most popular free AI detectors tool online — and for good reason. It’s fast, simple, and gave a 99.6% AI score in my test, which is among the highest.
It also highlights suspected AI text in red, which is helpful when editing. However, it’s not perfect — sometimes it flags human-written content incorrectly, especially on short or creative writing.
5. NoteGPT
NoteGPT is clean, fast, and surprisingly accurate. In my test, it detected 99.6% AI content, placing it right up there with top-tier tools like Originality and Copyleaks.
The interface is refreshingly minimal — just paste your content and go. It also highlights AI-generated parts, which makes editing easier. However, it doesn’t offer any extra explanation or scoring breakdown.
6. Scribbr AI Detector
Scribbr is known for academic tools, and their AI detector fits right in. It’s designed for students and researchers — the results feel polished, and it gave a 94% AI score during my testing.
The tool is easy to use and shows a clear verdict, but it doesn’t highlight which parts are AI-written. That makes it less useful for editing. Also, you need to create an account to use it more than once.
7. Phrasly AI
Phrasly AI looks simple, but it delivers strong results. It flagged my test content with a 94% AI score, which is solid — especially for a tool that’s relatively under the radar.
It doesn’t require any login, and the results are quick. However, there’s no highlighting, and the feedback is limited to just a score — so it’s more for quick checks than deep edits.
8. SurferSEO AI Detector
SurferSEO’s AI detector is built with content creators and marketers in mind. It scored a strong 99% AI in my test, making it one of the more reliable tools out there.
The interface is clean and fits well into Surfer’s ecosystem. However, it’s not very generous — free checks are limited, and there’s no highlighting to show which parts are AI-written.
9. EduWriter AI Detector
EduWriter is another education-focused tool that delivered solid results. It gave a 98% AI score in my test, which shows it’s reliable when detecting AI-generated content.
The interface is clean, and you don’t need to sign up to run a scan. However, there’s a word limit (around 1000 characters) and no highlighting, so it’s better for short academic paragraphs than full blog posts.
10. Writer.com AI Detector
Writer.com’s AI detector is part of its larger writing assistant suite — and while it’s simple, it does a decent job. It gave an 85% AI score in my test and works well for quick checks on short content.
The UI is clean and user-friendly. But there’s no text highlighting, and the tool doesn’t always catch subtle AI rewrites, especially on medium-length posts. Still, it’s helpful if you just want a fast yes-or-no result.
11. AIDetectors.io
AIDetectors.io keeps things minimal but gets the job done. It scored 85% AI in my test, which puts it among the better tools for free users.
You get a straightforward interface with fast results. However, there’s no highlighting, and the tool doesn’t offer any context or explanation — just a single score. It’s useful for basic checks but not ideal for deep analysis or editing.
12. Ryrob AI Detector
Ryrob’s AI detector is a hidden gem. It’s part of a blogger’s toolkit and scored 85% AI in my test — pretty solid for a free, web-based tool.
It’s clean, fast, and doesn’t require login. However, like many simple detectors, it only gives a single score and doesn’t highlight specific AI-written parts. That makes it more useful for a quick judgment than in-depth editing.
13. Ahrefs AI Detector
Ahrefs is a big name in SEO, and their AI detector feels like an extra tool in their writing suite. It gave an 80% AI score in my test — not the highest, but still decent for spotting basic AI content.
The interface is simple and clean, and it doesn’t require sign-up. But there’s no AI highlighting, and the detector doesn’t give much context or detail. It feels more like a quick assistant than a full analysis tool.
14. ISGen AI
ISGen AI is a lesser-known tool, but it performed fairly well — giving an 80% AI score in my test. It’s a quick, no-frills solution for basic detection tasks.
The interface is minimal, and you don’t need to sign up. However, it doesn’t highlight AI-generated content or explain its score. It’s more of a “quick check” tool than something you’d use for editing or deep analysis.
15. Sapling Ai Detector
Sapling’s AI Detector is fast, lightweight, and surprisingly helpful — especially for short-form content. It scored 73.3% AI in my test, and what makes it stand out is that it highlights individual phrases it believes are AI-generated.
That kind of feedback is a huge plus if you’re trying to rewrite content to sound more human. However, it’s best suited for short or medium-length content — the tool tends to miss more subtle or heavily edited AI in longer posts.
16. JustDone AI Detector
JustDone’s AI detector is part of a broader AI writing suite, and it performs reasonably well. It gave a 75% AI score in my test — not perfect, but decent enough to catch obvious AI content.
The interface is smooth and modern, and results come in fast. However, like many tools in this tier, it doesn’t highlight AI-written parts, and the results are limited to a single score without much explanation.
17. Undetectable.ai (Detector Tool)
Interestingly, while Undetectable.ai is known for bypassing detectors, its own AI detection tool is pretty decent. It gave a 76% AI score in my test, which is better than expected for a tool not focused solely on detection.
The interface is sleek and feels modern, but like many tools in this range, it only gives a basic score — no AI text highlighting or explanation. Still, it’s handy for double-checking content before or after using humanizers.
18. Smodin AI Detector
Smodin is part of a suite of academic tools, and its AI detector performed decently — showing a 67% AI score in my test. It’s not perfect, but still useful for catching obvious AI content.
The UI is user-friendly and results are fast, but the tool doesn’t offer any highlights or details — just a single percentage. It’s best for students or casual users who want a quick check.
19. ContentDetector.ai
ContentDetector.ai gave a 58.04% AI score during my test — not the highest, but still above the 50% threshold I used for this list. It’s a simple tool meant for quick checks, and while it gets the job done, it’s not very detailed.
There’s no highlighting or deep explanation. Just a clean interface and a score — useful for quick judgment, but not ideal if you’re editing or need sentence-level insights.
20. SurgeGraph AI Detector
SurgeGraph is better known for keyword tools and long-form SEO, but it also offers an AI detector. It gave a 49% AI score in my test — just below the cutoff, but I’ve included it because it’s still worth mentioning for SEO-focused users.
The interface is clean, and results come quickly. However, there’s no highlighting, and the tool doesn’t give much context beyond the percentage. It’s okay for a fast check, but not reliable enough for detailed content audits.
Can These Tools Be Fooled?
Here’s where it gets tricky.
After some experimenting, I realized that paraphrasing, adding personal anecdotes, and mixing sentence styles helps reduce detection — but none of these tricks guarantee 100% safety.
Also, AI detectors are always playing catch-up. Every time a new model (like GPT-4o or Claude) is released, most detectors become outdated — at least for a while.
Yes, many tools can be fooled — especially if you humanize your content first.
👉 Here’s my list of AI humanizers that actually work.
💡 Pro Tips to Bypass Detection (Without Losing Quality)
Whether you’re using AI to save time or brainstorm, here’s how you can stay under the radar while keeping your content valuable:
- Start with AI, finish with your brain.
Let AI give you structure, but rewrite key parts in your tone.- Use contractions, slang, and emotion.
Say “you’re gonna love this” instead of “you will enjoy this.”- Tell stories.
Even short personal examples make the text feel human.- Break grammar rules sometimes.
Start a sentence with “And.” Use sentence fragments. Just like this.- Edit line by line.
Don’t just rephrase everything with a tool. Think like a reader.
You can also use an AI humanizer tool to help rewrite paragraphs naturally.
Here are my top picks for AI humanizer tools in 2025.
10 AI Content Detectors NOT Worth Your Time (2025)
1. Duplichecker AI Detector
Scored just 0.5% AI, completely unreliable.
2. Decopy AI Detector
Extremely slow and failed nearly every test.
3. Writesonic AI Detector
Free only 3 times, often fails to load results.
4. Trinka AI Detector
Has a strict 500-word limit and failed to load detection score.
5. Cudekai AI Detector
1000-character limit and no meaningful results.
6. Monica AI Detector
Only accepts 250 words, results are inconsistent.
7. Gowinston AI Detector
Requires sign-up just to show the score — not worth it.
8. Summarizer.org AI Detector
Unclear scoring and weak AI detection.
9. Ahrefs Free AI Humanizer Tool
Fails detection tests and provides no useful feedback.
10. Undetectable AI Free (Humanizer)
Unlimited free use, but fails most AI detectors after humanizing.
Final Thoughts: Should You Worry About AI Content Detection?
Here’s the honest truth: Most readers don’t care if your content is written by AI — as long as it’s useful.
But algorithms, schools, and clients? They might.
So, knowing how to spot AI and how to edit around it is a handy skill in 2025.
At the end of the day, tools are just tools. Whether you’re using AI to assist your writing, or trying to make sure your content feels more “you” — remember this:
It’s not about hiding from AI detectors. It’s about making your content sound real.
Like something only you could write.
FAQs on the Best AI Content Detector Tools in 2025
Based on hands-on testing, the best AI content detector tools in 2025 include Originality.ai, Copyleaks, ZeroGPT, and NoteGPT. These tools stand out because they provide clear detection, highlight AI-generated parts, and work well even with advanced models like GPT-4.
When choosing among the best AI content detector tools in 2025, look for features like sentence-level highlights, accuracy with GPT-4 content, and a decent free word limit. Tools like Originality.ai or Copyleaks offer a great balance for professionals and casual users alike.
Mukesh Kumar
Hi, I’m Mukesh — a graphic designer who loves creating. On this blog, I test AI tools and share practical tips, honest reviews, and design resources that help creatives work faster. I only recommend tools I’ve personally used and found genuinely useful in real creative workflows. Everything I share is tested, useful, and made to save your time as a creative.
