Quillbot vs Undetectable.ai
Quillbot scores higher overall, 3.0 against 2.7 of 5.0, and leads in 5 of the six categories to 1. Which matters depends on the categories you weigh most.
Independently evaluated by huby · 2026-10-22 · scores free to read and cite
Overall scores
Category by category
A category is won on the higher score. Equal scores are counted for neither.
What the evaluation found
Quillbot
Strongest category: Use Cases & Pricing
Quillbot's commercial strategy is built around a freemium model that successfully attracts a large base of individual users, particularly students, by offering a limited free version to encourage upgrades. The paid plan bundles a comprehensive suite of writing tools into an affordable, all-in-one subscription that users rate highly for its value. While this approach has driven significant grassroots adoption, the product's features for businesses and institutions remain basic, generally limited to centralized license management rather than deep enterprise control.
Quillbot Research Brief, $35 →Undetectable.ai
Strongest category: Quality
Undetectable.ai demonstrates highly inconsistent performance, excelling at identifying simple, unedited AI or human writing but struggling significantly with more complex material. In controlled huby testing, the tool correctly identified all purely human-written documents but failed to flag two-thirds of AI-generated text that was edited or designed to be evasive. This performance gap extends to its rewriting feature, where the paid version can bypass some detectors while the free version is completely ineffective.
Undetectable.ai Research Brief, $35 →Go deeper on either one
The scores above are free. A Research Brief adds every subcategory scored, the assessment behind each one, and who should consider it - six pages, in the shape a buying decision actually needs.
Common questions
Is Quillbot or Undetectable.ai better?
On huby's independent evaluation, Quillbot scores 3.0 against 2.7 for Undetectable.ai, and leads in 5 of the six categories. Neither is better at everything - the category table above shows where each one leads.
How are Quillbot and Undetectable.ai scored?
Both are evaluated against the same framework, on the same 1.0-5.0 scale, from evidence tiered by source. The scores were published 2026-10-22. huby takes no payment to change a score or a rank.
How many AI detectors has huby evaluated?
9 text detectors, all against the same framework, which is what makes these two comparable at all.
What do I get that is not on this page?
This page is free and always will be: both overall scores, all six category scores and a verdict. A Research Brief adds the subcategory scores, the written assessment behind each one, and who should consider the product.