The Best AI Content Detectors in 2025

Today, we’re going to talk about a really interesting topic. You may have used it, or rather, you use it occasionally as a business, agency, or freelancer in the UK. I’m talking about AI content detectors.

If you were to run a simple Google query asking something like “What are the best AI content detectors?”, you’d be looking at a lot of content that has reviewed some of these tools.

But the truth is, more than a handful of the content about these proposed “best AI content detectors ” is biased. This is due to the affiliate relationship some of these websites have with these AI detectors, or sometimes they recommend their content detector.

What you’re reading right now isn’t going to be such content. In the next few minutes of this post, I’ll walk you through the five best AI detectors in 2025.

I’ll explain what makes these AI detectors stand out, how accurately they perform with different types of content, and which tools are totally worth your time and perhaps a subscription.

Sounds good? Then let’s get started right away.

What is an AI Content Detector

Quite frankly, I think the answer to this question is easy to figure out. But for clarity, an AI detection tool is a tool that analyses AI-generated text from various AI models like ChatGPT, Claude, Gemini, etc.

These tools came to the market around late 2022, when ChatGPT launched and sent you and me (and everyone else, actually) into a frenzy about AI-generated content.

And just like that, they have become really important if you’re a teacher, writer, or a business that needs to verify content authenticity.

But there is a little catch. These days, AI text checkers don’t only have to check for ChatGPT-generated content but also have to keep up with AI humanizers or AI content bypassers, as they’re also called.

Freelancer writers and students are becoming lazy about writing original content from scratch. They’re constantly looking for tools that can help them bypass AI content detection, knowing that website owners and brands can now detect AI content from ChatGPT and other models.

You’d be right to call it a cat-and-mouse game, with AI detectors trying to catch up with content humanization tools that actively try to mask AI writing as human-written.

This has led to several tools claiming to “humanize” or “bypass AI detectors,” making it difficult to find a reliable AI detector.

The Best AI Content Detectors at a Glance

AI Detector	Key Features	Free Plan	Paid Pricing
Copyleaks	High accuracy, plagiarism check, Chrome extension	Limited scans daily	AI Detector: £7.99/mo (annual) | £9.99/mo (monthly) | AI + Plagiarism: £13.99/mo (annual), £16.99/mo (monthly)
GPTZero	Clean interface, plagiarism check, sources finder	750 words per scan, 10,000 words monthly	Essential: £14.99/mo | Premium: £23.99/mo | Professional: £45.99/mo
Originality.AI	Multiple detection models, plagiarism check, readability analysis	750 words per scan	Pro: £14.95/mo | Enterprise: £179/mo | Pay-as-you-go: £30 (2,000 credits)
Quilbot AI Detector	Multi-language support, paraphraser, summarizer	1,200 words per scan, unlimited scans	£4.17/mo (annual) | £9.95/mo (monthly)
ZeroGPT	Simple interface, easy to use, additional tools	2,100 words per scan, unlimited scans	Premium: £9.99/mo | Plus: £19.99/mo | Max: £26.99/mo

How I Tested and Ranked the Best AI Content Detectors in 2025

Alright, let’s quickly go over how I vetted the five content detectors I’ll be reviewing here.

The process was pretty clear, with three key criteria with which I tested these tools. I performed tests for:

• Accuracy of results
• User friendliness of the detector
• And what’s the price like if you have to get a subscription

For user experience, I looked at how intuitive each platform was and the learning curve needed to get started.

What really caught my attention was how these tools handle free plans. Some AI content detectors don’t offer any free version, which isn’t great for trying before buying. Others give such limited free plans that you feel forced to upgrade, while a few provide genuinely useful free tiers that let you decide if you want to pay.

To test accuracy – the most important factor – I ran three different tests with each detector. First, I checked content directly generated by ChatGPT and Claude. Then, I tested another content rewritten by AI humanizers or bypass tools. Finally, I ran genuinely human-written content (written by me) through each detector.

This three-pronged approach helped me see which AI detector was truly reliable across different scenarios. After all, what good is an AI detector that flags human writing as AI-generated? Or one that misses obvious AI content?

I carefully examined 15 different tools on the market before narrowing down to these top 5 best AI content detectors that balance accuracy, usability and value. These represent the tools I’d actually recommend to colleagues and clients in 2025.

The Best AI Content Detectors in 2025

Let’s dive straight into the tools that actually deliver results, starting with the most reliable AI detector on the market today.

The Best AI Content Detector for Writers in 2025

1. Copyleaks

I’m going to hit the nail right on the head. Copyleaks is the best AI content detector right now in 2025. It’s competing shoulder-to-shoulder with GPTZero in the industry.

It’s in fact one of the oldest detectors, founded in 2015. So, they have over a decade of experience on their belt.

Copyleaks’ uniqueness lies in the accuracy of its results compared to other AI detectors. AI humanisers and paraphrasing tools can easily fool or bypass many detectors, including Zerogpt, Quilbot detector, Grammarly AI Detector and Sapling.

Trying to bypass Copyleaks is far more difficult.

The platform has almost no learning curve and is very easy to use. Signing up takes about two minutes; once you’re logged in, simply paste your content and hit the blue “Scan” button at the bottom right. That’s it!

There’s a free plan with limited daily scans for occasional use. There’s also a Chrome extension that performs scans without you having to visit the website and appears in a sidebar on your screen. It’s especially helpful if you need to check content without disrupting your workflow.

First AI-humanized content test screenshot using a humanizer tool:

Second AI-humanized content test screenshot using another different humanizer tool:

The screenshots above show that tricking Copyleaks detector using an AI content humaniser tool is very difficult. 

PRO TIP: For the most accurate result when using Copyleaks, I strongly recommend using the Copyleaks Chrome extension for detection.  

Copyleaks Pricing

Plan	Monthly Price	Annual Price	What You Get
Free	£0	£0	Limited daily scans
AI Detector	£9.99	£7.99/mo	100 credits monthly
AI + Plagiarism	£16.99	£13.99/mo	100 credits + plagiarism checking
Pay-as-you-go	£18.99	N/A	250 credits (no subscription)

The free plan is quite effective for solo freelancers without a lot of content to handle. The paid plans are more suitable for teams or agencies that manage large amounts of content. I particularly like the idea of a pay-as-you-go offering, which is ideal if your monthly needs change.

Pros and cons of Copyleaks

Pros:

More accurate compared to other AI content detectors
Difficult to trick with AI humanisers
Clean, simple design with almost no learning curve required
Convenient Chrome add-on for quick checks
Pay-as-you-go under flexible pricing options

Cons:

Regular users may find the limited free plan inadequate.
A little more expensive than some competitors

#2 Best AI Content Detectors After CopyLeaks in 2025

2. GPTZero

Launched in early 2023, GPTZero has quickly established itself among the most accurate AI detectors. The platform’s simple, contemporary design makes it really easy to use, even for new users.

After registering a free account, you are redirected to a screen with a scan menu on the left-hand side. To search for AI text, you can choose between basic and advanced scans. Other features, like source search, plagiarism check and general feedback, are also available.

What I particularly like about GPTZero is the fact that it explains its detection technique and shows you exactly which sections of text trigger the AI warnings. This openness allows you to understand the results instead of just giving a percentage.

With a free plan, you can only scan content of 5,000 characters (approx. 750 words) and 10,000 words per month. If you’re a business, agency or freelancer with a lot of content needs, you might have to switch to a paid plan.

Human written content test: 

AI-written content test:

First AI-humanized content test using a humanizer tool:

Second AI-humanized content test using another different humanizer tool:

From the screenshots above, GPTZero can easily spot AI-written content right away with no issues. It can also tell if the content was completely human-written accurately. Although it can spot AI-humanised content, it can somehow be tricked, and very few humanisers can do this out there. However, if you read the content that was able to bypass the detector, it was poorly written and has many errors that cannot be used in a blog except it was heavily edited by an editor.

GPTZero Pricing

Plan	Monthly Price	Words Per Month	Features
Free	£0	10,000	Basic scan, 750 words per scan
Essential	£14.99	150,000	Grammar check, AI vocabulary check
Premium	£23.99	300,000	Advanced scan, plagiarism check, writing feedback, sources and citations
Professional	£45.99	500,000	Team collaboration, batch scanning

Pros and cons of GPTZero

Pros:

Easy to use and clear interface
A clear detection system that shows exactly what triggers the artificial intelligence
Offers both basic and advanced scanning options
Includes additional features like source detection and plagiarism checking
Offers a decent free plan, you can test the service with
High accuracy with content generated directly by AI

Cons:

• The free plan word limit is quite restrictive
• Sometimes struggles with heavily humanized AI content

The Most Expensive AI Content Detector in 2025

3. Originality.AI Detector

Originality. AI is yet another contender for AI detectors, giving Copyleaks a run for its money. It was launched in late 2022 and soon proved to be a consistent content detection tool.

Although many AI humanization tools and content paraphrasers are flooding the market, it’s still a challenge to fool or bypass Originality.AI with such tools. Signing up takes less than a minute; all you need to do is link your Google account.

Originality offers three ways to search for AI content: Lite 1.0, Turbo 3.0 and a multilingual model. During my time using this detector, it’s clear that the Lite 1.0 model is more accurate than the Turbo model, which sometimes flags parts of human-written material as AI-generated.

Early in its development, Originality struggled with accuracy, as evidenced by many false positives where human-written content was incorrectly flagged as AI. However, the company has clearly gone to great lengths to get this problem under control, which now puts it up there as one of the best AI content detectors available.

They also offer plagiarism checks like Copyleaks; extra credits are used for further readability and grammar studies. The user interface works similarly: simply paste in your material, scan it, and you’ll get a clear percentage showing how much of the text appears to have been generated by an AI model.

AI-humanized content test using Quilbot AI Humanizer:

Human written content test: 

AI-written content test:

As you can see above, the Originality.ai detector can easily spot content written with AI models like Chatgpt and content entirely written by a human writer. However, it can be tricked or bypassed using an AI humaniser, in this case, the Quilbot AI humaniser.

Originality.AI Pricing

Plan	Price	Word Credits	Features
Pro	£14.95/mo	2,000 (up to 200,000 words)	AI detection, plagiarism check
Enterprise	£179/mo	25,000	Team features, API access
Pay-as-you-go	£30	2,000 (credits valid 1 year)	No subscription required

Another big downside before now was that Originality.AI didn’t have a free plan. But that’s not the case anymore. They have a free trial that allows you check up to 750 words on a single scan.

There are also subscription plans. I use and recommend the pay-as-you-go plan because, unlike the monthly subscriptions, the credits remain valid for up to a year, giving you freedom without stress.

Pros and cons of Originality AI

Pros:

• Highly accurate with direct AI content
• Multiple detection models for different needs
• Credits in pay-as-you-go plan last a full year
• Clean, professional interface
• Combined plagiarism and readability checking

Cons:

• Lite model is sometimes more accurate than their newer Turbo model

Most Affordable AI Content Detectors

4. Quilbot AI Detector

Quilbot is one of the oldest tools in the content area and offers a whole range of writing features.

Quilbot’s AI detector is characterised by its sophisticated study. Instead of a simple yes/no decision, it analyses content using four categories: AI-generated, AI-generated and paraphrased, human-written and paraphrased, and purely human-written. This helps you better understand the authenticity of the content.

Impressively, the detector supports multiple languages, including English, French, Spanish, German and Dutch. With its multilingual capabilities, Quilbot stands out from many competitors that only offer English.

The user interface consists of a clear white dashboard where you can paste in the content you want to check, with the tool functions neatly arranged in a sidebar. It’s really simple and intuitive. Perhaps best of all, you can even use the detector without registering or logging in.

With no daily or monthly limits, the free plan is very generous and allows you to check up to 1,200 words at a time. This kind of access makes Quilbot one of the best free AI detectors if you don’t want to spend money on a subscription.

Another thing I like about them is their openness to AI content. Although their detector is highly sophisticated, they make it pretty clear that no AI detector is 100% reliable or accurate, regardless of their stated accuracy ratings.

It’s really difficult to see this kind of honesty with competitors who claim their tool is 99% accurate, which is simply not realistic in the fast-changing artificial intelligence scene.

Human-written content test:

AI-written content test:

AI-humanized content test:

From the test carried out, while Quilbot did really well in spotting AI content and human written content, it was easily tricked with an AI humanizer.

Quilbot Pricing

Plan	Monthly Price	Annual Price	Features
Free	£0	£0	1,200 words per scan, unlimited usage
Premium	£9.95	£49.95 (£4.17/mo)	Unlimited access to all features

With just one paid premium subscription at £49.95 annually (just £4.17 per month) or £9.95 monthly, Quilbot offers amazing value for money. This gives you unlimited access to all features, making Quilbot the most affordable full AI detector on the market.

Pros and cons of Quilbot

Pros:

• Excellent free plan with generous word limits
• No registration required for basic use
• Nuanced four-category analysis of content
• Supports multiple languages (English, French, Spanish, German, Dutch)
• Honest about detector limitations
• Extremely affordable premium plan

Cons:

• Can be bypassed by some advanced AI humanizers
• Less accurate than Copyleaks or Originality with humanized content

Best Free AI Content Detector

5. ZeroGPT AI Content Detector

Although its effectiveness mainly depends on how you use it, Zerogpt is a good AI detector that has been running since early 2023. I emphasise that it “depends on how you use it” as this tool is not quite on par with Copyleaks, Originality, or GPTZero.

Its biggest drawback is its vulnerability to AI humanisers or content bypassers. These humanisers can easily fool Zerogpt, reducing its reliability when trying to spot AI-written content. However, it performs well when examining content written directly with Chatgpt, Claude, Gemini and other models.

The interface couldn’t be more straightforward. Simply paste in your content and click “Scan Text”. With unlimited scans per day or month, the free plan is incredibly generous, allowing scans of up to 2,100 words (15,000 characters) at a time.

In addition to AI detection, Zerogpt offers other tools that can be accessed via the menu on the left: Plagiarism Check, Grammar Check, Summary, Paraphrasing, Translator and Word Counter. Based on my observation using the tool, I wouldn’t rely on the plagiarism checker or grammar checker. They simply lack accuracy compared to dedicated tools like Grammarly.

ZeroGPT Pricing

Plan	Monthly Price	Features
Free	£0	15,000 characters per scan, unlimited scans
Premium	£9.99	Additional features, no ads
Plus	£19.99	Enhanced accuracy, priority support
Max	£26.99	All features, API access

When it comes to pricing, Zerogpt offers three paid subscriptions. Premium (£9.99/month), Plus (£19.99/month) and Max (£26.99/month). Practically speaking, I don’t think you’ll need a subscription if you intend to use just the AI detector.

As there are no restrictions on daily scans, the free plan is already great for basic AI detection. It should be enough for you unless you need certain premium features.

I ran a check using an 800-word AI content. From the first screenshot above, you can see that ZeroGPT can easily detect content written with ChatGPT. It’s the same result even with AI models like Claude and Gemini.

I ran a check using an 800-word completely human-written content. ZeroGPT also did a great job here to spot the content as human written. The 4.59% of AI shown is negligent.

In this third test, I scanned a 400-word document written by an ChatGPT but humanized with an AI humanizer. You can see from the screenshot that ZeroGPT vetted the content as 50% AI-written, which is actually 100%. This is because, as I said before, the ZeroGPT detector can be tricked and bypassed. There are several cases where the detector has only detected 20% AI from content curated with an AI content humanizer tool.

Pros and cons of ZeroGPT

Pros:

• Extremely generous free plan with no daily limits
• No registration required to use the detector
• Very simple, straightforward interface
• Fast results with minimal processing time
• Additional writing tools included
• Works well for detecting unaltered AI content

Cons:

• Easily bypassed by AI humanizers and paraphrasing tools
• Supplementary tools (grammar, plagiarism) lack accuracy

How to Use AI Detectors for More Accurate Results

First of all, let’s be brutally honest. If any brand claims its AI detector is 100% foolproof, it’s not true.

It’s nothing but a marketing strategy. The whole tech scene—AI detectors and AI humanisers—is like a never-ending game. One is getting smarter while the other is trying to catch up. It’s relentless.

Here’s a golden piece of advice, and I really mean it: never rely on the result of just one AI detector. That’s like asking a friend if your new haircut looks good; before you realise you’ll need a second opinion, maybe even a third! My good advice? You need to use at least two different detectors.

The combo that has worked for me is Copyleaks and GPTZero. Why these two in particular, you might ask? They’re both really advanced. Their different AI detection models make it extremely difficult for sophisticated paraphrasers or AI humanisation tools to bypass them as human-written content.

It’s much better when both detectors wave red flags and say, “Yes, this is AI,” than when you check with just one tool.

Use Cases and Benefits of AI Detectors

Okay, so why are these things worth the effort? What’s the goal? Well, they certainly have their moments.

1. Protecting academic integrity: These AI detectors make sure students are putting in their sweat and tears, not something that a robot created in five seconds. It’s about maintaining that learning criteria and making sure that people are actually learning to think, not just copying and pasting. Nobody wants a generation that’s not capable of coming up with original ideas.

2. Quality assurance of content: Publishers, websites, and anyone who produces content usually check for quality assurance. These detectors can check whether authors actually write content themselves. It prevents the internet from turning into a giant junkyard of generic, boring AI content that is of no use to anyone. We’ve all read posts that are just generic information, nothing you didn’t know before.

3. Recruitment and evaluation: This is an important factor for employment, especially for writing jobs. Companies are getting smarter. They are using AI detectors to check if applicants used Chatgpt to write their resumes. They want to see your skills and your real flair. It’s about hiring a real wordsmith.

4. Brand protection: Many brands are pretty zealous about this. They want every piece of content to be unique, to show what they’re really about. For many companies, that means content written by people with real points of view. They check every piece of content with a detector to maintain the standard.

5. Clarity on copyright and ownership: They can help prove a piece’s originality. This gives companies peace of mind that they are receiving genuine, human-written content.

Frequently Asked Questions (FAQS) About AI Detectors

What is an AI detector?

An AI detector is software that tries to determine whether a text was created by a human or an artificial intelligence like Chatgpt. It examines things like word patterns, sentence structures and small telltale signs. These tools are basically pattern recognisers and look for the fingerprints that AI usually leaves behind.

Should you use or trust an AI content detector?

Should you use them? They are indeed useful. Should you trust them without question? Not at all. They are not the whole toolbox; they are a tool in that box. And like I said, check them with more than one. No single detector is a miracle worker, but they can give you some pretty good clues.

Which is the most accurate AI detector in 2025?

If I had to pick a single detector today, in early 2025, I’d go with Copyleaks. When it examines human texts, it seems to make fewer mistakes and “false positives.” It’s pretty good at detecting AI text, even the material altered by humanisers.

Are AI detectors 100% reliable?

Not really. Let’s just get this straight. Anyone who says otherwise is selling snake oil. These instruments play a game with patterns, with probabilities. Occasionally, they misinterpret. They might overlook AI content or classify human writing as AI. That happens with AI tools.

Can AI detectors be tricked or bypassed?

Oh yes, they can. At least many of them can. Many of these “AI humanisers” can be found online. They try to trick the detectors by rephrasing and reshaping AI text. However, the really good detectors, the more sophisticated ones like Copyleaks or OriginalityAI, are quite different. It’s getting harder and harder to fool them permanently. This is the arms race I mentioned.

What is the best free AI detector?

The best free one? ZeroGPT is a reasonable candidate if you’re looking for something generous that won’t cost you a dime. Let’s be clear: It’s not very accurate. But for free access and not too many pesky restrictions on how much you can check, it’s high.

Conclusion

We’ve come to the end of this detailed guide. From everything I’ve shared so far, Copyleaks is arguably the best AI content detector on the market. GPTZero and Originality also do a really good job of spotting AI, Human, and humanised content. 

However, as I mentioned earlier, I strongly recommend you check the content with more than one detector for a more accurate perception of its originality. Again, no AI content detector is 100% accurate, as proven by all the tests I’ve carried out, so you should only use them as a guide when checking content. 

Lastly, writing quality SEO-optimised content is a lot of work. If you need help writing quality content for your website or business, send us a message or check out our SEO content writing services. We’d be happy to help. 

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