Content & copy edits
Surfaces edited headlines, pricing changes, swapped hero sections, and navigation changes — whether they were intentional or slipped in with another change.
Website Change Detection Without Writing Code
NorthDuty captures a screenshot of each monitored page on a schedule and compares it pixel-by-pixel against the previous capture. When something changes — a moved button, edited copy, a new banner, or a broken layout — the change surfaces as a visual diff with a changed-percentage figure, so you find out before customers do.
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Get alerted when a page changes — intended or not — without writing a single test.
What website change detection catches
Useful anywhere a visible change to a page can affect conversions, trust, or compliance.
Layout & structural shifts
Detects moved or missing buttons, broken grids, overlapping elements, and spacing changes that appear after a deploy or CMS push.
Vertically shifted content
The differ aligns content even when a banner is added or removed and the rest of the page moves down — so a single insertion does not flag the whole page as changed.
Change across more than one page
Managed URL screenshot sets let you watch more than the base URL, so change detection can cover the handful of pages that matter most.
See exactly what changed
The UI Changes view shows the monitored URL, the previous screenshot, the diff overlay, and the changed percentage.
UI Changes
Diff overlay with changed percentage
Changed regions are outlined over a dimmed version of the page, with unchanged areas faded back, so you can read what moved at a glance and open the full capture when you need detail.
Know the moment an important page changes
Pages change for reasons no uptime check can see: a CMS edit, a deploy, a plugin update, a third-party script, or an A/B test. Most of those changes are intentional, but some are not — and the unintended ones are the ones that quietly cost conversions.
Instead of asking you to maintain code, NorthDuty does change detection from real browser screenshots. Each scheduled capture is stabilized first — cookie and consent overlays are removed, media and carousels are paused, lazy images are eager-loaded, and the page is scrolled in passes to trigger deferred content — so that two captures of an unchanged page diff cleanly and only real changes show up.
Why screenshot-based change detection works
It catches the visible changes that matter without scripts, selectors, or per-element configuration.
- No code: add a URL and change detection runs on a schedule
- Pixel-level diff reports how much of the page changed
- Content alignment ignores pure vertical shifts so you see real changes, not noise
- Small sub-8-pixel differences are dropped as noise before a change is reported
- Cover landing pages, pricing pages, product pages, and other revenue-critical screens
How website change detection works
It runs automatically once a project exists, with a configurable cadence.
1
Add the base URL and any managed URLs
NorthDuty captures the base URL and any managed URLs added for broader screenshot sets — no scripts to write.
2
Scheduled, stabilized capture
On each run the page is stabilized and captured. The capture becomes the new candidate for comparison.
3
Pixel diff against the previous capture
NorthDuty aligns the two captures, diffs them pixel-by-pixel, and reports the changed percentage with a diff overlay.
4
Review and decide
Open the diff to see what changed, then decide whether it was expected. Alert rules can notify you when the visual difference crosses a threshold.
Related NorthDuty Pages
Explore pricing, feature details, solution pages, and related tools connected to this website monitoring use case.
Pricing
Pricing
NorthDuty plans are sized by how many checkout, signup, and login journeys you monitor: Free (1 daily journey), $29 Starter, $79 Pro, $199 Business, $499 Enterprise. 7-day full trial, no card.
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Features
Explore NorthDuty features: website health checks every 5 minutes, screenshot-based visual change detection, and AI-suggested user journey monitoring in one project.
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Solutions
Explore NorthDuty solutions for ecommerce website monitoring, SaaS website monitoring, agency website monitoring, and startup website monitoring.
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Deployment Monitoring
Automatically run health checks, visual diffs, user journeys, and API monitors the moment your site is deployed or your CMS publishes a change.
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Visual Regression Monitoring
Screenshot-based visual regression testing and website change detection for key pages — get pixel diffs on design, content, and layout changes, no code required.
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Screenshot Monitoring
Website screenshot monitoring with NorthDuty: scheduled, stabilized full-page captures of your key pages, stored over time and diffed against the previous baseline.
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Website Monitoring
Learn how NorthDuty combines health checks, screenshot diffs, and editable user journeys in one website monitoring project.
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Alerting
Send NorthDuty alerts to email, Slack, Teams, Discord, Google Chat, webhooks, Telegram, WhatsApp, and SMS.
Explore AlertingFrequently Asked Questions
Answers to common questions about this monitoring feature and when teams should use it.
What is website change detection?
Website change detection notices when a web page changes. NorthDuty does it by taking scheduled screenshots and comparing each one pixel-by-pixel against the previous capture, then reporting the changed percentage and a diff overlay.
Do I need to write code or selectors?
No. NorthDuty compares full-page screenshots, so there is nothing to script. You add a URL and change detection runs automatically on a schedule.
Will small rendering noise create false changes?
NorthDuty stabilizes each page before capture and drops sub-8-pixel difference components as noise, and it aligns vertically shifted content, so routine rendering differences are far less likely to be reported as changes.
How is this different from visual regression monitoring?
It is the same screenshot-and-diff engine framed for a different job. Visual regression monitoring focuses on catching regressions after releases; change detection focuses on knowing whenever a monitored page changes for any reason.
Call To Action
Start monitoring your website with NorthDuty today.
Add the pages that matter and let NorthDuty tell you, with a visual diff, the moment they change.
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