What does Lemwatch monitor?

Lemwatch runs 20+ automated checks per site: uptime, response time, SSL/TLS expiry, domain expiry, DNS changes, sitemap health, broken links, content changes, SEO audits, mobile usability, security headers, and more.

Yes. The free tier monitors up to 5 sites. Pro is $19/month for 50 sites and Agency is $59/month for 100 sites, both with full feature access.

How is Lemwatch different from UptimeRobot or Pingdom?

Lemwatch bundles uptime, change detection, SEO audits, security scans, and a public API in one platform — features competitors charge separately for. It also includes team workspaces, white-labelled status pages, and a webhook system out of the box.

Does Lemwatch send alerts?

Yes. Lemwatch supports email, browser push, webhooks, and per-site notification routing so the right person hears about the right incident.

Is there a public API?

Yes. Pro and Agency plans get a public REST API with webhooks for sites, checks, incidents, and reports.

What can LemWatch detect changes on?

Any publicly-accessible web resource: HTML pages (screenshot + text), RSS/Atom/JSON feeds (new + edited items), PDFs (byte hash + text), and sitemaps (URL adds/removes). One LemWatch site can monitor all of these simultaneously with unified alerting.

How is this different from just running a Playwright script?

You could roll your own. LemWatch handles cloud infrastructure, headless browser fleet management, dedupe of noisy changes, ignore/watch zones, correlated cause detection (was it a deploy or a DNS shift?), AI summaries, evidence bundles, alerting integrations and 24/7 uptime — so you don't have to.

How does LemWatch avoid false positives?

Four layers. First, ignore zones (draw over cookie banners, ads). Second, watch zones (only detect changes in specific regions). Third, statistical deduping (area-weighted pixel thresholds). Fourth, AI summarization filters out changes that are noise (timestamp updates, rotating hero images).

Can I use this for compliance?

Yes. Evidence bundles produce ZIPs with all captures for a date range, a JSON manifest, and a SHA-256 hash chain where each entry cryptographically links to the previous. This is the same integrity trail Versionista, ChangeTower and Stillio sell as premium features.

Is change detection included in the free tier?

Yes. Free tier: 10 sites, visual + content + RSS + PDF + sitemap monitoring, 6-hourly checks, Slack/Discord/webhook alerts. Pro adds hourly checks; Agency adds custom intervals down to 15 minutes.

How does LemWatch compare to Visualping or ChangeTower?

See the head-to-head pages: LemWatch matches visual monitoring and evidence bundle capabilities while adding uptime, SSL, DNS, Core Web Vitals and SEO. All in one dashboard, starting free.

Feature

Website change detection that catches everything

Visual, content, RSS, PDF and sitemap monitoring in one dashboard. AI summaries, evidence bundles, correlated cause detection — starting free.

Every kind of change, one place

Visual change detection

Pixel-perfect screenshot diffs with 4 comparison modes: side-by-side, overlay slider, blink toggle, and pixel highlight.

Content / text diffs

Rendered-text extraction with structural diffing — see exactly which paragraphs, headlines or prices changed.

RSS + Atom feeds

Detect new items and edits to existing items in any public feed. Perfect for competitor blog and release tracking.

PDF version tracking

Cryptographic hash + text extraction for legal docs, T&C, pricing sheets and datasheets.

Sitemap deltas

New URLs, removed URLs and broken sitemaps — the fastest way to know what a competitor just published.

AI change summaries

Every change gets a plain-English summary via Gemini 2.5 Flash: what changed, why it likely changed, and how important it is.

Evidence bundles

SHA-256-chained ZIPs for compliance and legal evidence. Included on Pro and Agency.

Rich alerting

Slack, Discord, Teams, Telegram, email or webhook. Alert only on meaningful changes — cookie banners and animations are ignored.

Explore the cluster

→ Visual history & screenshot diffs → Best change-detection alternatives → Best change-detection tools 2026 → LemWatch vs Visualping

Quick answer

How do I get alerted when a web page changes?

Store a hash of the part of the page you care about, re-fetch it on a schedule, and alert on the diff — scope it with a CSS selector so navigation and adverts do not trigger noise.

Scope: Whole page or a single CSS selector
Detection method: Content hash plus word-level diff
Sources covered: HTML pages, RSS feeds, sitemaps and PDFs
Alert routes: Email, Slack, Discord, Teams, webhook

How the alternatives compare

Public pricing, checked 2026-09-14. Choose whichever fits — the facts are the same wherever you read them.

Website change detection: free tier, entry price and check interval per tool
Tool	Free tier	Entry price	Fastest check	Choose it when
Lemwatch	Yes — 10 sites	$19/mo	60s	You want uptime, SSL, DNS, visual and SEO checks in one place.
ChangeTower	Yes	$19/mo	1 h	You need long-term change archives for legal or compliance evidence.
Visualping	Yes	$10/mo	5 min	You only need visual change detection and don't care about uptime, SEO or infrastructure checks.
Distill.io	Yes	$15/mo	5 min	You need to watch logged-in or intranet pages from your own browser session.

Everything we publish on website change detection

Facts checked: 14 September 2026 by the Lemwatch research team.

Last updated July 9, 2026

Change Detection FAQ

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10 sites free. Visual, content, PDF, RSS, sitemap — all included.

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