5 Best AI Content Detectors Reviewed

An AI content detector is a tool that analyzes text to determine if it was written by a human or an AI, using algorithms to assess linguistic patterns and compare them to known AI-generated and human-written content. 

How they work:

AI content detectors employ natural language processing (NLP) and machine learning (ML) techniques to identify AI-generated text.

AI detectors may be used to detect when a piece of writing is likely to have been generated by AI. This is useful, for example, to educators who want to check that their students are doing their own writing or moderators trying to remove fake product reviews and other spam content.

However, these tools are quite new and experimental, and they’re generally considered somewhat unreliable for now. Below, we explain how they work, how reliable they really are, and how they’re being used.

1. Surfer AI content detector

It should be noted that SurferSEO is a writing tool itself, meant for content creation that is SEO friendly so content writers can have their articles rank on search engines. It seems strange they both create content, and detect AI created content. It would seem like a conflict of interest. However, if they create machine generated content they must know what it looks like.

SurferSEO also offers various integrations from Surfer API to various extensions. It offers an AI humanizer of its own and an AI writing assistant that will help you edit your text with a grammar checker.

Surfer’s AI detector analyzes your text for patterns in style and tone, using machine-learning algorithms to generate a probability score indicating how likely your content is to be human or AI-written.

To get your results, you only have to paste your content (a minimum of 100 words) into the text box and give Surfer’s AI detector a few seconds to work its magic.
Surfer’s AI detector is free to use for content up to 500 words at a time.

For higher limits, you can sign up for the Essential plan, which offers unlimited AI detection along with a range of other SEO features.

2. QuillBot’s AI detector

Among QuillBot’s suite of popular paraphrasing and text optimization features is a pretty capable AI content detection tool.

There’s no sign-up process, which is always a plus—you can immediately start detecting by either pasting your written content into the text box or uploading the document directly as a PDF.
It performed quite well, but like all AI detection tools, QuillBot isn’t infallible. I recommend using it to get a general sense of whether your content is human-written, but never as definitive proof.

As for pricing, QuillBot is free to use if you’re okay with detecting a maximum of 1,200 words at a time.

If not, they offer a Premium plan priced at $4.17 per month, which allows for AI content detection of up to 25,000 words each month.

3. Turnitin AI checker

Turnitin, in addition to being a plagiarism checker, is an AI detector widely used in academia. Accounts are only available to institutions, instructors, and students.

It is quite a popular tool to detect AI generated content among teaching staff, since the incentive to avoid AI detection may be higher and more frequent in academic institutions.

Upload your document to Turnitin and provide a few essential details, like your region and the document title, to start detecting AI content.

It’s not the fastest AI detection tool—even relatively small documents can take up to a minute to analyze.

But once it’s done, you can see the overview of your results on the dashboard.

This includes the word count, similarity score, AI score, and a few other relevant details about the document.

For a more in-depth look at your AI score, click the PDF option next to the AI overview on your dashboard to download the detailed report.

Here, you’ll get a breakdown of the score, including the percentage of the document that is AI-generated and the portion that’s been AI-generated but paraphrased with another tool.

Scrolling down, you’ll also see exactly which segments of your text Turnitin detected as AI.

Turnitin doesn’t have its pricing publicly listed. To set up an account, you’ll have to contact the sales team to get a quote.

4. Hive AI moderator

Hive is another online AI detection tool.

Along with detecting AI-generated text, Hive also offers tools to detect AI-generated images, videos, and even audio.

To start off, enter your content into the text box—a minimum of 750 characters, though Hive recommends at least 1,500—then click submit.

Hive’s AI detection tool also comes with a Chrome extension, allowing you to analyze content directly on web pages, saving you the hassle of constantly juggling between tabs.

Keep in mind, though, that the browser extension limits AI detection to only up to 2,048 characters (roughly just a few paragraphs of content), which isn’t very practical unless your needs are just as minimal.

It is free to use and doesn’t come with any paid options—so what you see is what you get, with no hidden pay-to-unlock features.

5. Ahrefs AI content detector

Ahrefs’ AI Content Detector uses a language model that learns patterns, grammar, and vocabulary from large amounts of text data – then uses that knowledge to generate human-like text based on a given prompt or input. The generated text combines both the model’s learned information and its understanding of the input.

Ahrefs is widely regarded as a go-to SEO tool, allowing users to identify new content pillars, perform keyword research, and track website traffic.

Recently, they launched an AI text humanizer, claiming to turn AI-generated text into text that sounds more human-written, thus bypassing human or software detection.

The Ahrefs AI content detector is among the platform’s many free SEO and writing tools.

The interface is simple enough to use—you don’t need to create an account or log in. Just enter your text into the provided box and click Analyze.

The detector and content humanizer are combined into one tool, so you’ll see options for generating different text variations and other features that might not immediately make sense.

You can safely ignore these extras.

It’s extremely fast and doesn’t take longer than a few seconds to generate a result.

But this is quickly overshadowed by the tool’s rather large limitation: you can only enter around 300–350 words at a time.