What is an AI Detector?
Software that analyzes text to determine if a machine generated it.
An AI detector examines a written passage, then assigns a probability score, indicating how likely it is that the text was produced by a large language model instead of a human author. By 2026, the leading detectors include names like GPTZero, Turnitin AI, Originality.ai, Copyleaks, ZeroGPT, Sapling, Winston, and Crossplag. While their internal classifier designs, strictness thresholds, and training models vary, they all fundamentally rely on two core linguistic signals: perplexity and burstiness.
What is an AI Humanizer?
A tool designed to rephrase AI-generated text to resemble human writing.
An effective AI humanizer takes text from a language model and reworks it, maintaining the original meaning while deliberately altering the surface-level characteristics that detectors look for. High-quality humanizers actively manipulate perplexity (making word choice less predictable) and burstiness (introducing more varied sentence lengths). They also meticulously remove common AI vocabulary patterns-think words like "leverage," "transformative," or "comprehensive"-and ensure the rewritten text matches the original's register. Inferior humanizers are often just glorified paraphrasers; they typically fail when put to the test against more advanced detectors.
What is Burstiness?
The extent to which sentence length and complexity fluctuate within a text.
Consider human writing: it naturally features a blend of very short, punchy sentences and much longer, more intricate ones. In contrast, AI-generated prose tends to settle into a consistent, mid-range sentence length. GPTZero, for example, assigns a burstiness score from 0 to 100, where a low score is a significant indicator of AI authorship. ByGPT actively enhances burstiness by interspersing fragments with complex sentences, varying paragraph sizes, and avoiding the AI tendency to string together several similarly structured sentences.
What is Bypass Rate?
The success rate of humanized text passing an AI detector as human.
This is industry jargon for how often a humanizer successfully "fools" a specific AI detector. ByGPT regularly updates its public, per-detector bypass rates. As of mid-2026, our average across the seven main detectors sits at approximately 99.6%. Naturally, these rates might dip slightly when a detector rolls out a significant model update, but we work quickly to patch our system, and the rate soon recovers. You won't find a humanizer that achieves 100% success on every single passage, across every detector, all the time. Any claims to the contrary are simply not backed by large-scale testing.
What is Citation Freeze?
A feature that prevents a humanizer from altering citations or references.
Accuracy in citations is paramount, especially in academic and research contexts. Imagine "Smith (2019)" mistakenly becoming "Smyth (2019)"-that's a problem, and it can be incredibly difficult to fix later. ByGPT's Frozen Keywords feature allows users to specifically mark author names, dates, page numbers, and direct quotations as untouchable. Our rewriter then passes these elements through without any changes, ensuring your crucial academic data remains perfectly intact.
What is Copyleaks?
An AI detector trained on billions of pages of content.
Copyleaks operates using a proprietary neural classifier. Unlike some detectors that focus on sentence-by-sentence analysis, it examines the entire document holistically. This detector is frequently encountered in the publishing industry, within content agencies, and as part of corporate plagiarism detection workflows. ByGPT tests against Copyleaks every week, currently maintaining a 99.5% bypass rate.
What is Crossplag?
An AI detector featuring cross-language semantic analysis.
Crossplag uniquely combines AI detection capabilities with traditional plagiarism analysis. What sets it apart is an additional cross-language layer that specifically identifies patterns indicative of AI-driven translation. It's particularly stringent on academic and formal texts. ByGPT addresses this challenge through native rewriting tailored for over 30 different languages.
What is an Em-dash Tell?
The frequent use of em-dashes (.) as an indicator of AI writing.
It's a strange quirk, but large language models, especially those trained extensively on books, tend to overuse em-dashes for parenthetical phrases. Most human writers in 2026, however, don't rely on them nearly as much; commas, periods, and standard parentheses are far more common choices. ByGPT's internal prompt, by design, completely prohibits the use of em-dashes to avoid this particular AI signature.
What are Frozen Keywords?
Specific terms chosen by a user that a humanizer leaves unaltered.
This feature is incredibly useful for ensuring accuracy and consistency. You can use it for product names, essential SEO keywords you're targeting, brand taglines, citations, highly technical jargon, or proper nouns. ByGPT offers support for frozen keywords across all of our service plans, giving you precise control over your output.
What is Generative Engine Optimization (GEO)?
Optimizing content so it's more likely to be referenced by AI answer engines.
This represents the evolution of traditional SEO for the 2025-2026 era. While SEO focused on getting your content to appear in Google's "blue links," GEO's objective is to get your information cited directly by large language models when they formulate answers to user queries. It's about becoming a primary source for AI.
What is GPTZero?
A widely used AI detector, especially popular among educators since 2023.
Edward Tian, then a Princeton senior, developed GPTZero during his winter break in 2022-2023, releasing it to the public on January 2, 2023. It evaluates both perplexity and burstiness, but also employs a more sophisticated neural classifier for its analysis. ByGPT consistently achieves a 99.7% bypass rate against GPTZero.
What are Hedge Words?
Phrases like "probably" or "in many cases," which humans often use but AI frequently omits.
When writing in informal contexts, prose that sounds overly confident or lacks any qualification can sometimes be a red flag for AI. Real people instinctively temper their statements, acknowledging uncertainty or nuance. A humanizer, therefore, strategically incorporates these "hedge words" wherever the tone and register of the text permit, making the writing sound more natural and less machine-like.
What is a Human Score?
A detector's reported probability that a text was human-written.
Typically presented on a scale from 0 to 100, where 100 signifies unmistakably human content and 0 means it's unequivocally AI. Samples processed and validated by ByGPT aim for scores of 95 or higher across all seven of the major AI detectors, ensuring our output is consistently recognized as human-generated.
What is a Large Language Model (LLM)?
A neural network, extensive enough to predict text sequences accurately across diverse subjects.
Platforms like ChatGPT, Claude, Gemini, Llama, Mistral, and DeepSeek all share a fundamental operational characteristic: they function by predicting the next most statistically probable word in a sequence. This inherent tendency often results in prose with low perplexity-a key signal that AI detectors are trained to identify.
What is Originality.ai?
An AI detector primarily targeted at publishers and content agencies.
Launched in 2022 by founder Jon Gillham, Originality.ai utilizes a strict binary classifier, often employing a hard percentage cutoff for detection. This is frequently the detector of choice for freelance content clients who run checks before authorizing invoice payments. ByGPT maintains a strong 99.4% bypass rate against Originality.ai.
What is a Paraphraser?
A tool that simply replaces words with synonyms; it's weaker and more detectable than a humanizer.
Consider tools like Quillbot's "spinner" mode: they primarily function by swapping individual words for their synonyms. This superficial type of editing doesn't actually alter the underlying perplexity or burstiness of the text, meaning AI detectors can still easily flag the output as machine-generated. A true humanizer goes far beyond this, actively restructuring sentences, varying lengths, and systematically removing those tell-tale AI vocabulary clusters.
What is Perplexity?
A measurement of how predictable a sequence of words appears to a language model.
If a language model finds the next word in a sequence very easy to guess, that text has low perplexity. Conversely, if the next word is surprising or less obvious, the text exhibits higher perplexity. AI-generated text typically displays consistently low perplexity because it defaults to common, predictable word choices. Human writing, however, naturally features a much wider range of perplexity.
What is Reading Level?
A metric for text complexity, usually correlated with educational attainment or grade level.
ByGPT offers users four distinct reading level options: High School, University, Doctorate, and Journalist. This setting directly influences the vocabulary range used, the average sentence length, and the overall density of the rewritten text, allowing for tailored outputs that fit specific audience needs.
What is Register?
The degree of formality and the social context for which a piece of writing is intended.
For instance, academic writing employs a formal and structured register, adhering to specific conventions. A Reddit post, on the other hand, typically uses a much more casual register. It's crucial for a humanizer to accurately match the original input's register, ensuring the rewritten text sounds appropriate for its intended audience and context.
What is Sapling?
An AI detector featuring a per-sentence classifier, known for a high false-positive rate.
Sapling's approach involves flagging individual sentences, making it effective at identifying specific AI-generated paragraphs inserted into human text. However, this method can also lead to it incorrectly flagging dry, fact-based human writing as AI-produced. ByGPT addresses this by carefully chunking text and separately managing sentence-level rhythm during its processing.
What is Speakable Schema?
Schema.org markup indicating content suitable for voice assistants.
When a specific section of content is tagged with Speakable schema, it signals to voice assistants and AI engines that this material is suitable for being read aloud as a direct answer to a user's query. Combining clear, concise definitions with Speakable markup represents a highly effective strategy for Generative Engine Optimization (GEO).
What is Turnitin AI?
Turnitin's integrated AI detector, widely used in academic submission systems.
Turnitin AI automatically generates an AI score for every assignment submitted, running in parallel with its traditional plagiarism detection. Its detection threshold is set conservatively. If a submission receives a high AI score, it doesn't automatically result in a penalty; instead, the work is flagged for the instructor's review and further investigation.
