LinkedIn Tops New Study of AI-Written Posts as Synthetic Content Spreads Across Social Media

A new analysis by AI detection firm Pangram suggests that artificial intelligence (AI) is becoming a pervasive presence on social media, with LinkedIn emerging as the most AI-saturated major platform in the company’s dataset.

Drawing on more than 1 million user-scanned posts collected through Pangram’s opt-in Chrome extension since April 24, the study found that AI-generated and AI-assisted writing now appears across every major platform examined.

Longform Posts Show the Highest AI Rates

According to the report, the average rate of fully AI-generated content across all scanned items was 13.8%. Longer posts proved especially susceptible, “one in four longform items” exceeding 250 words were flagged as entirely AI-generated.

Substack stood out as an exception, with longer articles slightly less likely to be AI-written than shorter ones.

LinkedIn Leads in AI Saturation

LinkedIn accounted for nearly two-thirds, 62%,of all AI-generated posts identified by Pangram, despite representing only about a third of the scanned content.

More than 40% of the platform’s long-form posts were flagged as fully AI-generated.

Pangram concluded that “people are overwhelmingly willing to use AI to speak on their behalf in professional settings that are associated with their real identity,” noting that LinkedIn itself offers built-in AI writing assistance.

X Shows the Highest Combined AI Presence

When AI-assisted and mixed-authorship posts were included, X recorded the highest overall share of AI-influenced long-form content.

Nearly half of its articles contained either fully AI-generated or partially AI-written text, while only 53.2% were classified as entirely human-authored.

The findings mirror broader concerns about the growing volume of AI-produced writing appearing across the internet.

Replies Remain More Human

Reddit exhibited one of the lowest overall AI rates, largely because comments and replies, 98.1% of which were deemed human-authored, made up the bulk of the scanned material.

Top-level posts, however, were significantly more likely to contain AI-generated text, a pattern that also appeared on LinkedIn.

Pangram emphasized that “AI writing is now a problem everywhere on social media,” but argued that greater transparency can help users make informed decisions about where to focus their attention.

While the study relies on the company’s own detection model and on data volunteered by extension users, it offers one of the largest snapshots yet of the growing role of AI-generated content in online discourse.