WebChange Detector for MainWP

WebChange Detector for MainWP adds a visual safety net to the updates you already run from your MainWP Dashboard. Before the updates, it captures screenshots of the pages you selected on every child site. It then installs the updates and captures the same pages again. The screenshots are compared automatically, and you instantly see which pages changed, with the visual difference highlighted.

Everything runs from your MainWP Dashboard. Nothing is installed on your child sites.

What is an on-demand check?

An on-demand check is a visual diff you run around a change you make yourself, like installing updates. WebChange Detector takes a screenshot of each selected page before the change, applies the change, takes another screenshot after, and compares the two automatically. The comparison runs on desktop and mobile, and the AI ignores moving parts like sliders, carousels, ads and animations, so you only get flagged on changes that actually matter. In MainWP, this on-demand check is wrapped directly around the updates you run from your dashboard: pre-update screenshots, the updates, post-update screenshots, and the comparison all happen in one run across all your child sites.

How it works

1. Create a free WebChange Detector account at webchangedetector.com if you do not have one yet, then copy your API token from your account and enter it in MainWP.
2. Enable the child sites you want to check.
3. Sync each enabled child site’s pages with “Sync WP URLs” so its pages become available, then select the pages to check (desktop and/or mobile).
4. Click “Run visual checks & updates” on your MainWP dashboard or Updates page.
5. The plugin captures pre-update screenshots, installs all pending updates, captures post-update screenshots and compares them. Before the pre-update screenshots and after the updates, the cache on each child site is cleared automatically, so the screenshots always show the real, freshly generated state of the site.
6. Review the results on the Checks tab: every page with a visual change is flagged, including an AI summary of what changed.

Features

• One-click WCD Updates: pre-update screenshots, updates, post-update screenshots, comparison: all in one run across all child sites.
• Start a run where you already work: “Update Selected with Checks” and “Update All with Checks” on MainWP’s own Updates page (WordPress, Plugins, Themes and Translations) with MainWP’s row selection, on each child site’s Updates subpage, from the WCD Updates widget on your Operations dashboard and every site overview, or for the whole fleet from the Run tab.
• Automatic cache clearing: the child site’s cache is cleared before the pre-update screenshots and after the updates, so screenshots never show a stale cached page. Works with 20+ caching plugins (WP Rocket, LiteSpeed Cache, W3 Total Cache, WP Super Cache and more) through the MainWP Child plugin, with nothing extra to install.
• Page selection per site: choose which URLs are checked, separately for desktop and mobile.
• Check settings per site: screenshot region, difference threshold, alert emails, which devices new URLs are activated for, Basic Auth, static IP proxy, screenshot delay, and CSS or JS injection.
• Checks overview: all runs across your sites with filters, change percentages and side-by-side comparisons.
• Live run popup: a Pre-update, Updates, Post-update and Done timeline with per-site progress, and automatic resume if you navigate away mid-run.
• Your account in the dashboard: sign up on the Account tab or connect an existing account with your API token, and see your plan, remaining checks and active sites.
• Auto-enable new sites: optionally provision every newly added MainWP child site for visual checks automatically.

External service: WebChange Detector

This plugin relies on the WebChange Detector service (https://www.webchangedetector.com) as a third-party service to capture, store and compare the screenshots. A WebChange Detector account is required (free plan available).

The plugin sends data to api.webchangedetector.com only after you have entered your API token or submitted the account signup form, and only in these circumstances: when you create your free trial account from the Account tab (your first and last name, email address, a hashed version of your chosen password (never the plain text password), your dashboard site’s domain and server IP address are transmitted to create the account), when you connect or verify your account, when you enable a child site or sync its page URLs (the public URLs and page titles of that site are transmitted), when you start a visual check (screenshots are taken of the selected public URLs), and when you review or update results. Your API token is sent with each request to authenticate your account. No data about your WordPress users or any non-selected content is transmitted.

• Service: https://www.webchangedetector.com
• Terms of use: https://www.webchangedetector.com/terms-of-use/
• Privacy policy: https://www.webchangedetector.com/privacy-statement/

Requirements

• A MainWP Dashboard (the free MainWP plugin) with at least one connected child site.
• A WebChange Detector account and API token. If you do not have an account yet, create a free one at webchangedetector.com; the free plan includes monthly checks. See plans for paid options.