---
title: "Visual diff thresholds explained — Lemwatch Help"
description: "Tune how sensitive visual monitoring is — from tiny pixel shifts to major layout changes."
canonical: "https://lemwatch.com/help/visual-diff-thresholds"
source: "https://lemwatch.com"
---

# Visual diff thresholds explained

> Tune how sensitive visual monitoring is — from tiny pixel shifts to major layout changes.

## Quick answer

 Sensitivity is a 0–100 slider. Lower = more sensitive (any pixel change alerts). Higher = only large layout changes alert. Default is 5% — good for most marketing pages.

## What it controls

- The percentage of pixels that must differ before an alert fires

- Whether antialiasing and minor color shifts count as changes

- How text-diff scoring is weighted against pixel-diff scoring

## Where to find it in Lemwatch

 **Visual Monitoring → [page] → Settings → Sensitivity slider**.

## How to tune it

- Start at the default (5%).

- If you get noisy alerts on rotating banners or ads, raise to 10–15%.

- If you're missing small text edits (typos, price changes), lower to 2%.

- For legal/pricing pages, combine a low threshold with an ignore zone over dynamic areas.

- Save. The next run uses the new threshold.

## FAQ

### Why did a change below my threshold still alert?

 Text diff scores separately. A single character change on a page with words counts even if pixel diff is under threshold.

### Can I have different thresholds per page?

 Yes — thresholds are per-page, not per-site.

## Related

- Visual monitoring setup

- Ignore zones

- Reducing visual noise


## Related

- [Help centre](https://lemwatch.com/help)
- [Set up visual monitoring for a page](https://lemwatch.com/help/visual-monitoring-setup)
- [Ignore zones for visual monitoring](https://lemwatch.com/help/ignore-zones)
- [Reducing false visual alerts](https://lemwatch.com/help/reducing-visual-noise)
- [Monitor a single element with CSS selectors](https://lemwatch.com/help/css-selector-monitoring)
- [Lemwatch pricing](https://lemwatch.com/pricing)
- [What is the visual monitoring diff threshold?](https://lemwatch.com/help/visual-monitoring-diff-threshold)
- [Approving and dismissing visual changes](https://lemwatch.com/help/visual-change-approvals)