---
title: "Rotating content noise (visual + text diff) — Lemwatch Help"
description: "Lemwatch scrubs rotating banners, timestamps, and random ads so they do not fire visual alerts."
canonical: "https://lemwatch.com/help/rotating-content-noise"
source: "https://lemwatch.com"
---

# Rotating content noise (visual + text diff)

> Lemwatch scrubs rotating banners, timestamps, and random ads so they do not fire visual alerts.

## Quick answer

 Enable **Scrub rotating noise** on any visual monitor. Lemwatch samples the page 3 times back-to-back, treats anything that changed between samples as noise, and diffs only what stayed stable.

## What it does

- Captures 3 quick samples on each check run

- Diffs samples against each other to identify volatile regions

- Automatically excludes those regions from the change score

- Applies only to that run — no permanent mask is stored

## Where to find it in Lemwatch

 **Visual Monitoring → [page] → Advanced → Scrub rotating noise**.

## How to enable it

- Open the page in Visual Monitoring.

- Click Advanced → toggle Scrub rotating noise .

- Save.

- Next run captures 3 samples and auto-scrubs volatile regions.

- Review the first alert after enabling to confirm noise is gone.

## FAQ

### Does this slow down checks?

 Yes, ~2–3× longer per run. Only enable on pages with rotating content.

### Does it replace ignore zones?

 Complement, not replacement. Use ignore zones for known-noisy regions; scrubbing catches new noise.

## Related

- Reducing visual noise

- Ignore zones

- Visual diff thresholds


## Related

- [Help centre](https://lemwatch.com/help)
- [Reducing false visual alerts](https://lemwatch.com/help/reducing-visual-noise)
- [Ignore zones for visual monitoring](https://lemwatch.com/help/ignore-zones)
- [Visual diff thresholds explained](https://lemwatch.com/help/visual-diff-thresholds)
- [Hysteresis band explained](https://lemwatch.com/help/hysteresis-band-explained)
- [Reading the alert quality scorecard](https://lemwatch.com/help/alert-quality-scorecard)
- [Lemwatch pricing](https://lemwatch.com/pricing)
- [RSS Alert Feeds](https://lemwatch.com/help/rss-feeds)