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Website change monitoring.
Know what matters.

OnChange monitors web pages and APIs, preserves before-and-after evidence, and alerts your team when something changes. Keep accessibility audits current and focus on the work that needs another look.

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5 free monitors. No credit card required.

Less wondering.
More knowing.

Start with accessibility assurance: a narrated film in under two minutes. Then explore change detection and alerts.

Accessibility assurance1:52

Keep accessibility work current.

Follow a form-label regression from preserved evidence through retesting and an independent review.

  • Bind work to preserved evidence
  • Focus keyboard and screen reader retesting
  • Record the reviewer’s decision
Explore accessibility assurance

English narration · Captions included

Read the full transcript

An accessibility audit records a moment in time. Then the website changes. A form field loses its label. Which evidence still holds? OnChange helps your team focus the next review.

Start with a defined scope. Preserve the pages, screenshots, HTML, and findings you evaluated. Here, the public Citylights sample gives the team a captured record across four pages, with the scope visible.

Bring automated findings and manual evaluation together. Record keyboard and screen reader checks, assign the work, and attach the evidence. Bind each completed test to the exact element or component it covered, then send it for review.

After a linked page changes, OnChange compares the preserved before and after. In this example, the email label was removed. The affected target is visible, so the team knows exactly what needs a fresh check.

The impact inbox explains three outcomes. Unaffected evidence carries forward only when its target, context, styles, and proof chain agree. Affected evidence needs retesting. Uncertain evidence needs attention too. Every decision keeps its reason, so uncertainty stays visible.

Reopen the affected work. Restore the label relationship, verify keyboard behavior, and check the screen reader experience. Save fresh evidence and let an independent reviewer approve the result. The decision stays connected to the release that made the retest necessary.

Give clients a clear record of scope, coverage, evidence, and continuity. Human evaluation stays central. Keep accessibility work current as your website changes. Explore OnChange accessibility assurance.

Download the transcript

Illustrative form-label regression. Product screens use demonstration data. English narration and captions explain the essential visual changes.

Change detection1:00

The change. The context. The next step.

Follow one pricing edit from capture to a routed, evidence-backed alert.

Explore change detection
Read the written walkthrough
  1. Your pricing page changed overnight. Did anyone notice?
  2. Add the source: a URL, a check interval, and optionally one element to watch. OnChange captures the baseline right away.
  3. Compare: the baseline shows the Pro plan at $12, the current page shows $15, and the free-trial button is gone.
  4. Decide: an AI summary, a 91% confidence score, the signals behind it, and the impact.
  5. Route the signal to Email, Slack, Discord, or a webhook. Cosmetic changes are ignored.
  6. One URL in. One clear decision out.

Illustrative product walkthrough. Figures shown are examples. Music only, no spoken audio.

Intelligent alerts1:00

The signal you need. A quieter inbox.

Watch APIs, sitemaps, and prices, and alert only when your rule is met.

Explore smarter alerts
Read the written walkthrough
  1. Most change alerts are noise: timestamps, rotating ads, and session tokens.
  2. Watch anything: an API contract, a sitemap, robots rules, or one element on a page.
  3. Write the rule in plain English, such as: alert me when the Pro plan price drops below $50.
  4. Ignore the rest with CSS selectors, JSON paths, pattern masks, and a confidence threshold. 38 alerts become 1.
  5. Know why: the JSON change is matched to the commit that shipped it.
  6. Different teams ask different questions. The record stays exact.

Illustrative product walkthrough. Figures shown are examples. Music only, no spoken audio.

The full picture, always

An alert is only the beginning.

Get the evidence behind the change, and a clear path forward.

Browse all features

Snapshot comparison

Keep the proof.
Skip the guesswork.

Revisit the page before and after a change. The original HTML, CSS, and screenshots stay together, ready to compare.

Saved page evidenceExample
Before

Team plan

$12/ month
Get started
After

Team plan

$15/ month
Get started

Price changed +$3 / month

  • HTML
  • CSS
  • Screenshot
Explore snapshot comparison

Accessibility assurance

Your audit moves
with your website.

Connect audit evidence to the pages it covers. When your site changes, review affected or uncertain evidence and retain the checks proven unchanged. Human reviewers confirm the retest results.

Evidence reviewExample
A release changed the navigation.

Bring the affected evidence back into focus.

  1. Baseline approvedYour signed-off evidence is saved.
    Recorded
  2. Navigation & focus orderReview the checks this change affects.
    Retest
  3. Verify and sign offKeep a clear record of the review.
Explore accessibility assurance

A report you can explore

See the pages. Open the evidence.

A real four-page sample with preserved views and accessibility findings. No account needed.

Explore the sample report

Simple to start

One URL.
A little more peace of mind.

  1. 1

    Add your source

    A page, an API, or a whole site. Set how often to check.

  2. 2

    Make the signal yours

    Choose what matters. Filter out the changes that don’t.

  3. 3

    Get the right heads-up

    Clear evidence, delivered where your team already works.

Fits right into your workflow

EmailSlackDiscordWebhooksAll integrations

Made for your kind of work

Different teams.
The same need to know.

Find your workflow

Accessibility agencies

Keep audit evidence current, focus retesting, and give clients a clear record.

Explore agency workflows

SEO & growth teams

Catch changes to titles, canonicals, sitemaps, and competitor pages.

Explore SEO monitoring

E-commerce teams

Follow prices and availability. Know when a change crosses your threshold.

Explore price tracking

Engineering teams

Watch API contracts and production pages, with the context to investigate.

Explore API monitoring

Start small. Stay in control.

Your first five monitors are on us.

Choose the coverage and check frequency your team needs.

Free

$0forever

Evaluate monitoring on five URLs.

Get started free
5 monitors30 min checks
  • Text, API, sitemap, and robots.txt monitoring
  • WCAG scans and all alert channels
  • 90-day history and REST API access

Pro

For growing teams

$12/mo

For focused teams and client work.

Start Pro
50 monitors1 min checks
  • Visual diffs and JavaScript rendering
  • AI summaries, semantic alerts, and change chat
  • 50 monitors with checks as fast as one minute

Business

$39/mo

For larger portfolios and faster checks.

Start Business
300 monitors30s checks
  • Multi-region change classification
  • Alert-triggered automations
  • 300 monitors with checks as fast as 30 seconds

Enterprise

Custom

For critical coverage and dedicated support.

Contact sales
Unlimited monitors10s checks
  • Unlimited monitor allowance and 10-second checks
  • Higher AI and regional usage ceilings
  • Dedicated support and custom operating terms

Every plan includes 90-day history and all alert channels.

Compare all features
What else is included in every plan?
  • Text and structured API diffs
  • Sitemap and robots.txt monitoring
  • Automated WCAG scanning
  • Email, Slack, Discord, and webhook delivery
  • 90-day change history
  • REST API access

Good questions

A little clarity
before you start.

More on what you can watch,
and how OnChange keeps you informed.

All monitoring questions

What does OnChange monitor?

OnChange monitors web pages, API responses, sitemaps, and robots.txt files on a schedule. It can detect edited copy, a redesigned section, a changed price, a removed CTA, a different API response, a new accessibility violation, a title tag or canonical URL update, a sitemap URL addition or removal, or a robots.txt rule change.

How often should I monitor important pages?

Use faster checks for revenue-critical pages, pricing, APIs, and launch pages. Daily or weekly checks are usually enough for evergreen content, legal pages, and documentation. OnChange supports intervals from 30 minutes on Free to 10 seconds on Enterprise.

Can OnChange monitor JavaScript websites, APIs, and specific page elements?

Yes. OnChange can monitor REST and JSON endpoints and use CSS selectors to watch a specific price, button, table, or content block. JavaScript rendering is available on paid plans, and you can ignore headers, ads, and other page elements that create noise.

Can I track accessibility regressions after a website update?

Yes. OnChange uses axe-core to track detectable accessibility issues between scans and links audit evidence to monitored pages. Changes can reopen affected or uncertain evidence for retesting. Automated scans cannot establish WCAG conformance on their own; manual and assistive-technology checks still require a reviewer.

Can I reduce noisy change alerts?

Yes. Target a specific element with CSS selectors, ignore headers or ads, mute volatile JSON paths or sections with regex masks, set a confidence threshold, or write a plain-English rule such as 'alert me when the Pro plan price drops below $50.'

How is website change monitoring different from uptime monitoring?

Uptime monitoring tells you whether a page responds. Website change monitoring tells you whether the page still says, shows, and returns the right thing. The two are complementary: a page can be online while its price, content, metadata, API payload, or accessibility state is wrong.

Explore monitoring by goal

Read the guides
Website scoping reportsAccessibility agency workflowsMonitoring questions and answersWebsite change detectionVisual difference monitoringSEO change monitoringAPI and JSON monitoringAccessibility regression monitoringCompetitor website monitoringPrice and ecommerce trackingCompliance and policy monitoring

Next time it changes,
you’ll know.

Start with the page you care about. We’ll keep an eye on it.

Start free monitoringFree to start. No credit card required.Or explore the interactive demo