Scribbr AI Detector is part of the Scribbr suite (known for proofreading, plagiarism checks). You paste or upload your text and it returns a confidence score: how likely it is AI tool, AI-refined, or human.
It flags sentences or paragraphs that look suspicious so you can revise them. It supports several languages not just English.
The engine calculates patterns like predictability, complexity, word choice variety. If something is “too clean” or “too regular,” it leans toward AI content flag.
If there’s variation, small oddities, or unique phrasing, it leans toward human. Because many writers mix human + AI edits, the tool isn’t perfect treat it as guidance, not judge.
You can use it for free (limit ~1,200 words per test). If you need more use or part of Scribbr’s academic
tools, you’ll hit their paid tiers:
for ~7,500 words: $19.95,
for ~50,000 words: $29.95,
for large docs: $39.95 these are bundled with their other services like proofreading. So the “pure detector” use is free up to a point, then you move into paid bundles.
Have a look on
Scribbr’s YouTube presence: 416,000 subscribers
Instagram followers: 2,905
LinkedIn followers: 11,824
These show a strong video / AI content engagement, modest social media audience.
When writing long content, split it into chunks so each fits into free mode. Run detection, then focus editing around flagged sentences.
Add your own voice quirks, anecdotes, unusual phrasing to humanize. Run detection again to see if score improves (i.e. becomes more “human”).
Rely on your own reading and gut AI tool helps but you decide.