Originality.ai finds 46% of sampled web articles likely AI

Originality.ai’s September tracker reports found that 46% of sampled long-form web articles were classified as likely AI, while LinkedIn topped five social platforms at 78%. The findings suggest AI-written content remains common online, but its prevalence varies sharply by platform and content length.

Why it matters: - Originality.ai’s latest tracker shows AI-generated or AI-assisted writing remains widespread across both editorial publishing and social media. - The September data suggest the level of likely AI content in sampled web articles has held steady for three straight reports. - The platform split on social media points to uneven exposure for publishers, marketers and readers depending on where content is posted.

What happened: - Originality.ai analyzed 2,000 randomly selected long-form English-language articles from 1,105 unique domains captured by Common Crawl in September 2026. - The company classified 921 articles, or 46.05%, as Likely AI. - A separate Social Media AI Tracker found LinkedIn had the highest share of sampled posts classified as Likely AI at 78%. - The tracker also found X at 62%, Threads at 62%, Facebook at 54% and Reddit at 29%.

The details: - The web-article result closely matched July’s 46.3% and August’s 45.6%, indicating stable levels across the three reports. - Among sampled articles with at least 1,500 words, 59% were classified as Likely AI. - Among sampled articles with 1,000 to 1,499 words, 52% were classified as Likely AI. - LinkedIn and X increased from the previous report. - Threads, Facebook and Reddit declined from the previous report. - Facebook fell from 65% in July to 54% in September, a drop of 11 percentage points. - Reddit recorded the lowest proportion among the platforms studied. - Reddit findings reflect August 2026 posts because its data collection runs one month behind the other platforms. - The reports cover sampled content, not all content published online. - Originality.ai used a 15% AI allowance when classifying content as Likely AI. - Social media samples covered English-language posts, with post-length criteria varying by platform. - Originality.ai’s research focuses on the presence of AI-generated content across the web and social media.

Between the lines: - The steady web-article rate suggests AI detection is not catching a one-off spike, but a persistent baseline in sampled online publishing. - Longer articles appear more likely to trigger the Likely AI classification, which may matter for publishers that rely on long-form content production. - The gap between LinkedIn and Reddit underscores that AI content prevalence is not uniform across social platforms.

What's next: - Originality.ai will continue publishing monthly tracker reports on likely AI content across web articles and social media. - Future reports will show whether the recent stability in web publishing holds and whether social platform rankings shift again. - Readers can access the September Dead Internet Tracker Report and the September Social Media AI Tracker Report for more information.