AI Text Detection: Comparison of 7 Best Detectors
In the second half of 2025, the number of texts created by artificial intelligence surpassed half of all textual content on the internet. Thus, the majority of articles you can currently find on Google or other browsers were generated using AI.
The rapid development of this field has led to the creation of AI detectors. These are primarily used in academia – to check student and scientific works (theses, term papers, dissertations, research articles, and developments). In 2026, Antiplagiat.Vuz already has a built-in AI detector that analyzes every submission, and professors are increasingly penalizing students who use neural networks to complete assignments.
Where can students check their work for AI online for free? In this article, we'll review the most popular services.
Why Check Text for AI
After its widespread adoption, AI has greatly simplified human work. Searching for information, comparative analysis, and content generation now take significantly less time. Educational institutions strive to keep pace with the times and have officially permitted the use of AI in student assignments. However, generative AI tools and chatbots (ChatGPT, Perplexity, Deepseek, and others) cannot be considered reliable sources of information, and work entirely created by artificial intelligence cannot be evaluated by the same criteria as human-authored work.
Therefore, universities are actively adopting AI text detectors. However, education and science are not the only fields where AI text detection has become an indispensable tool. Copywriting, SEO optimization, business, and economics also require detectors for generated text, which address the following tasks:
Verification of Authenticity. Fact-checking text is beneficial for students, professors, copywriters, and entrepreneurs alike. One should not blindly trust neural networks on matters concerning factual information (e.g., historical data, statistics, names, and dates). Artificial intelligence is prone to "hallucinations" and can generate false statistics and cite non-existent sources.
Assessment of Originality and Style. Texts written by neural networks are often formulaic in structure and share similar stylistic traits. Checking content for AI in creative and authorial works (e.g., blogs, forums, advertisements) helps identify suspicious fragments that may need revision before publication.
Upholding Academic and Professional Integrity, Maintaining Equality in the Scientific Community. Human-conducted research cannot be equated with research conducted by artificial intelligence. As noted, AI tends to fabricate facts, so the scientific community cannot entrust neural networks with discoveries, experiments, or the validation of theories. Ethically, science must remain honest and truthful, and authors themselves must bear responsibility for their findings.
SEO. Search engines may downgrade articles and sites with automatically generated AI content if it does not provide direct value to the reader. Built-in AI detectors analyze materials and determine whether the text was written by a human or a machine – and, if by machine, how useful it can be.
Many companies are already integrating AI detection tools into their ecosystems. In recent years, there have been increasing cases of AI fraud, including on a particularly large scale. As a result, cybersecurity and data protection have become critical concerns for both companies and their clients in 2026.
Comparative Analysis of AI Text Detection Services
For our test, we generated 2 essays (in Russian and English) about the sun and about rain. After generation, the texts were not modified in any way. We did not provide any additional instructions in the prompt besides the language and text length (maximum 600 words). Here are the texts we obtained:
Солнце: Могучий тиран и добрый отец Каждое утро, когда первый луч золотит верхушки деревьев, мы редко задумываемся о том, что видим настоящее чудо. Солнце для нас — это привычный желтый круг на небе, источник загара и хорошей погоды. Но если заглянуть за ширму обыденности, оно предстает перед нами в своей пугающей и величественной реальности. С астрофизической точки зрения, Солнце — это гигантский термоядерный реактор. В его недрах каждую секунду миллиарды тонн водорода превращаются в гелий, выделяя колоссальную энергию. Температура в центре светила достигает 15 миллионов градусов, а давление таково, что мы не можем даже вообразить его. Оно находится на расстоянии 150 миллионов километров от Земли, и тем не менее этот путь свет преодолевает почти за 8,5 минут. Если бы Солнце вдруг погасло, мы узнали бы об этом только спустя это время — и мир погрузился бы в вечную ночь. Однако Солнце — это не просто физический объект. Это краеугольный камень нашего существования. Земная жизнь возможна лишь потому, что звезда дает нам оптимальное количество тепла и света. Благодаря фотосинтезу в листьях растений солнечная энергия превращается в пищу для всех живых существ. Оно управляет погодой, океаническими течениями и временами года. Без Солнца Земля превратилась бы в ледяную глыбу, летящую в безвоздушной пустоте. Но роль Солнца не исчерпывается биологией и физикой. Оно — один из главных героев человеческой культуры. Наши предки были мудрее нас в своем отношении к светилу. Они обожествляли его: Ра в Египте, Ярило у славян, Инта у инков. Солнце было символом справедливости, правды и неотвратимости возмездия. В нем видели всевидящее око, которое наказывает зло и награждает добро. И хотя сегодня мы не приносим жертв богам, мы все еще ощущаем его власть: солнечный свет лечит депрессию, поднимает настроение и дарит нам витамин D. Тем не менее, наше светило остается могущественным и опасным. Мы видим его ласковым, но стоит вспомнить о солнечных вспышках, корональных выбросах массы и ультрафиолете, разрушающем ДНК. Оно напоминает нам, что жизнь на Земле — это не право, а привилегия, которую нужно заслуживать. Еще пять миллиардов лет — и Солнце начнет умирать, расширяясь до орбиты Земли. Оно поглотит нашу планету, и от всего, что мы создали, не останется и следа. Глядя на солнце в полдень, сложно поверить в его конечность. Оно кажется вечным. Но именно эта иллюзия учит нас главному: ценить каждый прожитый день. Солнце — это великий часовщик, который отмеряет время нашей жизни. Мы — дети Солнца, и наша задача — помнить об этом, беречь то тепло, что оно нам дарит, и пока есть свет, стремиться сделать мир лучше. |
The Poetry of Rain There are few natural phenomena as universally evocative as rain. For some, it is a nuisance, a grey curtain that descends to ruin picnics and dampen spirits. For others, it is a symphony, a cleansing ritual, and a source of profound peace. To truly experience rain, one must not just see it, but listen to it, smell it, and feel it. It is not merely weather; it is an atmosphere. I remember the rain of my childhood summers best. It would arrive without warning, transforming the dusty streets into a temporary network of rushing, chocolate-brown rivers. We would watch from the porch, faces pressed against the cool glass, as the world outside dissolved into a blur of green and grey. The air would grow heavy and electric, and then the first fat, warm drops would splatter on the pavement, releasing a unique perfume—petrichor—that earthy, sweet scent of dry ground meeting water for the first time in weeks. It was the smell of relief. But rain is not a single entity; it is a thousand different moods in one. There is the soft, misty drizzle of a London morning that mists the windows and softens the hard edges of the city, turning streetlamps into glowing orbs of amber. This rain encourages introspection, a slow walk with a collar turned up, a chance to get lost in one’s own thoughts. Then there is the ferocious summer thunderstorm, a percussive masterpiece of drumming on rooftops and rattling against gutters. The crack of thunder and the sudden flash of lightning remind us of nature’s raw, untamed power, humbling our technological pretensions. And finally, there is the gentle, persistent rain of a quiet afternoon—the kind that encourages you to build a fire, brew a cup of tea, and finally read that book that has been gathering dust on your nightstand. In our modern, air-conditioned lives, we often fight to keep rain at bay. We build shelters, carry umbrellas, and check weather apps, treating rain as an obstacle to be avoided rather than an experience to be embraced. Yet, to step out into a warm rain, to feel it on your face, is to feel profoundly alive. It is a direct, unmediated connection to the sky. It washes away not just the dust from the streets, but the static from our minds. I have come to believe that rain is the world’s way of resetting. It forces us to slow down, to retreat indoors, to listen. In the frantic pace of daily life, a rainy day is a rare and precious gift—a permission slip for stillness. It is a reminder that not everything needs to be bright and sunny to be beautiful. There is a deep, resonant beauty in melancholy, in the grey scale, in the quiet lullaby of water against the windowpane. So, the next time the sky darkens and the first drops begin to fall, do not curse the inconvenience. Instead, open a window. Listen to the rhythm. Breathe in the clean, wet air. Watch as the world is polished anew. Rain is not an interruption; it is a song. And if you listen closely, you might just find it singing directly to you. |
Мы проверили получившиеся тексты через 7 ИИ-детекторов и собрали результаты:
Service | Result (English / Russian) | Core Features and Characteristics |
100% / 100% | Provides an exact percentage of AI content and highlights suspicious fragments. Includes paraphrasing and "humanization" functions within the same interface. | |
isFake.ai | 100% / 100% | Multimodal detector: analyzes not only text but also images, video, and audio. For text, it provides a detailed report: overall AI likelihood score, highlighting of suspicious fragments, and instructions for interpreting results. |
GPTZero | 100% / 75% | Offers integration with Google Docs, Chrome, Canvas, Zapier, and API. When text is uploaded, it shows overall AI percentage and highlights suspicious phrases. Widely used in education, but lacks a Russian‑language interface. |
isgen.ai (Isgen AI) | 84% / 60% | Russian‑language detector supporting over 80 languages. Shows overall AI score and "Human/AI/Mixed" markup, highlights suspicious phrases. Features a built‑in AI humanizer. |
GigaCheck | «AI» / «AI» | Russian AI detector from Sber designed for Russian text. Does not provide a percentage, only a verdict – "likely AI" (based on predominant content). |
QuillBot | 61% / 45% | Web service for paraphrasing and text generation, includes an AI detector. Provides AI probability as a percentage and highlights suspicious sections. Offers a built‑in text humanizer and other tools (grammar, paraphrase). Supports multiple languages. |
MyDetector.ai | 54% / 4% | Online detector with file upload support (PDF, DOCX, PPT, TXT). Highlights each AI sentence and shows AI percentage per sentence, provides explanations ("why AI?") for each fragment. Has paraphrasing and humanization modes. |
Detailed Review of the Best AI Text Detection Services
ReText.AI
The ReText AI detector checks text for AI content and immediately displays the percentage of generated material, with individual highlighting of the most suspicious fragments. After analysis, you can directly proceed to paraphrasing and "humanization" functions to correct and improve the content. In international tests, our AI detection model demonstrated a leading position and achieved high accuracy at PAN-2025.
In our experiment, ReText successfully identified both texts as 100% AI. The service is convenient for Russian-speaking users (interface in Russian) and students: on one site, you can check spelling, paraphrase text, detect generated fragments using the detector, and immediately humanize them.
Drawbacks include: the service is freemium (limits apply), and when checking very short fragments, it may produce inconclusive results (the larger the text, the lower the margin of error).
isFake.ai (⚠️ VPN Required)
isFake.ai is a foreign platform for multimodal authenticity verification of content (text, images, video, audio). isFake.ai promises "transparent proof" of results: during text analysis, it highlights suspicious fragments and outputs a confidence score indicating the likelihood of AI generation. According to official data, isFake.ai's models are trained on millions of real and synthetic examples, providing high accuracy in material analysis.
The interface is not adapted for Russian-speaking users but is intuitive. In our experiment, isFake.ai produced 100% confidence in AI generation for both the English and Russian texts. Another plus: multimodality (you can check images, video, and audio on the site). isFake.ai is a convenient tool for journalists and researchers working with multimedia.
For Russian students and copywriters, the main downside is the lack of Russian localization – the interface is entirely in English. Additionally, isFake.ai does not offer a "humanization" or paraphrasing tool; it is solely a detection tool. And, of course, the free version has limitations. We recommend it for those working with large datasets who want to verify the authenticity of not only texts but also other forms of content.
GPTZero (⚠️ VPN Required)
GPTZero is one of the first and best-known AI detectors (developed as a student startup, now a commercial product). According to its creators, it "allows you to identify content created by large language models (ChatGPT, GPT-4, and others)." Technologically, the service is geared toward the education sector: there are extensions for Google Docs, Chrome, Canvas, etc.
In our test, GPTZero correctly analyzed the English text, showing a 100% AI result, while the Russian text showed 75%. GPTZero's detection model claims 99% accuracy in identifying AI text in its own tests.
The service interface is entirely in English. Its strong suit is integration with educational platforms and clouds: you can easily check text from Google Docs, upload files from Google Drive, and use the browser extension. Detected suspicious phrases are highlighted in the report.
The service is useful and convenient for users of the Google ecosystem, educators, students, copywriters, and journalists. However, it is primarily designed for English texts, as our results suggest that the AI detector is less responsive to Russian-language materials.
isgen.ai
isgen.ai is a modern multifunctional service that promotes itself as the "most accurate Russian AI detector" and supports over 80 languages (significantly more than most competitors).
The user interface includes a dedicated "AI Detector" section where you can upload a file or paste text (maximum 5000 characters). Results are displayed in a breakdown: overall AI score, as well as "Human / AI" percentages. It is claimed that the system analyzes text at the phrase and sentence level, highlighting parts that exhibit more obvious AI markers.
In addition to the detector, isgen.ai offers a free "AI Humanizer" – a tool that rewrites text to make it more natural and removes formulaic AI structures. In our tests, isgen.ai showed 84% AI for the English text and 60% for the Russian text. The service is well-suited for students and copywriters working with Russian: the Russian interface and detailed analysis allow for refining "AI-like" text.
Among the downsides, we note the lower accuracy in AI detection; however, even the 60% result remains one of the best when a foreign service handles Russian text. Also, some features (e.g., advanced detector or humanizer) are only available via subscription. Overall, the service can be recommended to anyone writing in Russian: it provides a transparent report and tips for improving the text.
GigaCheck by Sberbank
GigaCheck is a Russian AI detector developed by Sberbank (SberDevices) and designed for Russian text. According to developers, it is a "detector for determining the authorship of Russian-language texts."
Unlike other services, GigaCheck does not currently show a percentage of generated content or "confidence"; it only gives a general verdict ("likely AI" or "likely human"). This detail limits the model's usability, but it can be useful for quick preliminary checks and filtering out generated work at the first stage.
GigaCheck currently evaluates text based on "predominant content": if there is a mix of human and AI, it determines which is more prevalent. In the near future, they promise to add identification of specific AI fragments.
In our case, GigaCheck identified both texts as "likely AI." This tool is primarily for organizations (universities, publishers, major portals) that want to automate uniqueness checking in Russian. For ordinary users, it remains somewhat of a "dark horse": it does not provide a breakdown and lacks additional text-processing functionality.
QuillBot
QuillBot is a well-known online tool for paraphrasing and writing, which recently added an AI detector feature (you need to select this function from the options before checking). The free QuillBot detector "analyzes text and identifies content generated by ChatGPT, GPT-5, Gemini, Claude, and other AI platforms." The scan results provide an AI probability percentage with explanations.
The service highlights sections it deems most suspicious and shows why the text was flagged (e.g., "text is too predictable"). Unfortunately, the site does not have a Russian-language interface, so English proficiency is desirable for optimal use of QuillBot. The site also offers an "AI Humanizer" and other language tools (grammar, rewrite), so you can easily edit problem areas within the same interface.
In our tests, QuillBot detected 61% AI in the English text and 45% in the Russian text. These are moderate scores: the service is less "strict" than some competitors. Pros include an intuitive interface and additional functions (paraphrase, humanizer) for editing text, plus a Google Chrome extension. Cons include lower confidence metrics (especially for Russian text) and no Russian version of the site.
MyDetector.ai (⚠️ VPN Required)
MyDetector.ai is a free online AI detector with an emphasis on speed and detail. The site claims results are delivered "in real time." The service allows pasting text or uploading a file, and within seconds displays the result. Any suspicious phrase is highlighted, and MyDetector.ai provides explanations for why a particular sentence was flagged. This helps users understand the metric.
In our tests, MyDetector.ai showed 54% for the English text and only 4% for the Russian text. In addition to speed and detailed breakdown, pros include support for large text volumes and multiple formats (PDF, DOCX, PPTX, TXT), as well as a Russian version of the site. Additionally, MyDetector has a built-in "AI Humanizer."
Cons include poor results in our testing, lack of premium options without registration, and the need for a VPN connection. Based on our results, it appears that at least for Russian text, the detector remains somewhat weak.
How AI Detectors Work (Technical Section)
In simple terms, the operation of an AI detector involves searching for AI markers in text and making a decision about its origin based on the frequency of these markers.
AI detectors deeply analyze statistical and structural features and patterns in text; they look for grammatical constructions and formulaic phrases commonly used by neural networks. It is important to note that no AI detectors use definitive proof to identify results; they only estimate the probability that content was generated.
Some of the algorithms used to evaluate text for AI presence include:
- Perplexity Assessment. When generating text, any neural network selects the most probable next word from its "vocabulary." This makes the text smoother and stylistically consistent, but also predictable. For this same reason, you yourself can sometimes distinguish AI text from human text simply by the words used and their arrangement. Humans write more chaotically and may use lexical turns and phrases that are unexpected from a probability theory standpoint.
- Sentence Uniformity (Burstiness). Humans write in a more disjointed manner, alternating longer and shorter sentences. The text may not appear as a single stable line but as a constantly changing rhythm – sometimes accelerating, sometimes more subdued. Neural networks write in a uniform rhythm and do not allow sharp fluctuations in sentence length.
- Pattern and "Vector" Analysis. AI detectors have learned to extract the digital footprint of neural networks and compare it against their databases.
AI detectors, like generative neural networks, possess vast databases on which they continually retrain to improve and keep up with updates from their "competitors."
Limitations and False Indications
No technology can be perfect. The best AI text detectors also make mistakes, and these errors are generally divided into two categories:
- False Positive – when human-written text is flagged as generated. This typically occurs when the text has a high level of predictability or when a person writes in an academic style.
- False Negative – when AI-generated text is not flagged by the detection system. Unfortunately, margin of error exists, and AI detectors are constantly forced to "catch up" with generative neural networks and chatbots. The primary goal of an AI text detector is to continuously reduce the error rate through retraining and expanding its database.
In addition to false positives, AI detectors face other limitations. Texts written by non-native speakers are often flagged as AI-generated due to higher predictability and the use of clichéd phrases. International university students may face double difficulty when passing Antiplagiat and AI detectors with essays, theses, and term papers, even if they write without using neural networks.
Online text AI detectors may also struggle with very short texts, where it is impossible to properly track patterns and the author's individual style. It is important to remember: an AI text detector always evaluates only probabilistic indicators of individual words and grammatical structures, not the uniqueness of the idea or the current context of the material being checked.
How to Reduce AI Markers
Manually reducing AI markers in text is a difficult and time-consuming task. Paraphrasing text, replacing formulaic phrases with more "human" ones, varying sentence length, and choosing appropriate synonyms to preserve meaning and logic can take anywhere from half an hour for a short essay to several sleepless nights for a 100+ page thesis.
Fortunately, in 2026, this is no longer necessary. The ReText.AI Paraphrasing and Humanization tools are designed to modify text online to pass Antiplagiat.VUZ and AI detectors. Here's how to quickly humanize text using a neural network:
- Upload your text to the AI detector for checking – the tool will quickly analyze the text and provide a generation probability percentage;
- Go to the Online Paraphrasing Tool and paste your generated material. In the lower left corner of the computer screen (below your text in the mobile version), select the "strong" Paraphrasing level. The neural network will select synonyms, rephrase to increase originality, and modify grammar where possible.
- Add your neural-network-paraphrased text to our Online AI Text Humanization Tool. Wait a few minutes, and you will receive an updated result capable of passing any detector and Antiplagiat.
Frequently Asked Questions
What is an AI text check?
An AI text check is an analysis performed using a specialized detector that assesses the likelihood that the text was created by a neural network. Such services look for AI markers: predictable phrases, uniform sentence structure, formulaic style, and other signs of machine generation.
Which AI detector is best for Russian text?
For Russian text, it is better to choose services with a Russian-language interface and support for Russian materials – ReText.AI, GigaCheck, isgen.ai. ReText.AI is convenient because it displays the percentage of AI content, highlights suspicious fragments, and immediately offers editing tools.
Can an AI detector make mistakes?
Yes, any AI detector can make mistakes. Sometimes human text is identified as generated – this is called a false positive. The opposite can also occur: AI text may go undetected. Therefore, test results should be treated as a probabilistic estimate rather than absolute proof.
Why might a text be identified as AI-written?
A text may receive a high AI score if it is too uniform, formulaic, predictable, and resembles typical neural network output. Detectors often look for consistent sentence length, generic phrasing, clichés, a lack of individual style, and an overly "smooth" text structure.
How can I reduce AI markers in text?
To reduce AI markers, you need to make the text more natural: vary repetitive phrases, add authorial logic, diversify sentence length, remove formulaic constructions, and choose more precise wording. To speed up the process, you can use the Paraphrasing and Humanization tools at ReText.AI.
Is AI text checking suitable for a thesis or term paper?
Yes, AI detectors are often used for preliminary checks of theses, term papers, essays, and research works. Such checks help identify suspicious fragments in advance that might raise questions from professors or the Antiplagiat.Vuz system, allowing you to refine the text before submission.
Is it necessary to check text for AI before publishing on a website?
Yes, especially if the text was created with ChatGPT, DeepSeek, Perplexity, or other neural networks. A check helps assess the quality of the material, find formulaic fragments, and improve style. For SEO, it is important that the text is useful, natural, and written with the reader's interests in mind, rather than appearing as automatically generated content.