← Cases
United StatesTechnology and telecom2023 – ongoing

Yelp

LLM detection of inappropriate language in reviews

Yelp's language model helped moderators stop more than 23,600 reviews from publishing in 2023

WorkingCompany's own claimOfficial ↗

Problem

Yelp needed to keep threats, harassment, lewdness, personal attacks and hate speech out of its reviews. Moderators could not read every review as it arrived.

Approach

Yelp's machine learning team took a language model from the Hugging Face hub and fine-tuned it lightly to sort reviews into appropriate and inappropriate. The team set the decision threshold on simulated traffic to favor high precision. The model then went to live traffic, and flagged reviews went to Yelp's User Operations team for manual review.

Results

more than 23,600 reviewsreviews moderators prevented from ever publishing in 2023 with the model's help, per YelpCompany's own claim[1]

Takeaway

Yelp kept people as the final decision-makers and tuned the model for precision, so moderators only saw the reviews most likely to break the rules.

Categories

Business function
Production and quality
Innovation type
Process innovation
Evidence
Company's own claim

Sources

  1. Yelp's AI pipeline for inappropriate language detection in reviews
    Yelp Engineering Blog12 Mar 2024Company publication

Source summaries

[1]Yelp Engineering Blog12 Mar 2024

Yelp's machine learning engineer describes how the company fine-tuned a language model to flag egregious reviews and how it was deployed behind a service. Flagged reviews go to human moderators. Yelp reports that the system helped prevent more than 23,600 reviews from publishing in 2023. No precision or recall values are given.

Full details are in the original sources.

Added 2 Nov 2026 · Updated 2 Nov 2026
Open case page ↗