Compare
OnChange vs ChangeTower
ChangeTower is a polished, marketing-leaning page monitor that focuses on visual and content alerts. OnChange covers the same ground and adds the things engineering and agency teams need: API monitoring, accessibility scans, sub-minute frequency, and a REST API.
Both products detect when web pages change and notify you. The difference is depth on the technical side. If you're a marketing team watching competitor landing pages, ChangeTower is a fine fit. If your monitoring footprint includes JSON APIs, deploy-aware debugging, or accessibility compliance, OnChange is the broader platform.
| Feature | OnChange | ChangeTower |
|---|---|---|
Free plan available OnChange free: 5 monitors, every feature. ChangeTower free: 3 monitors, limited features. | ||
Cloud-based, runs without a browser | ||
Sub-minute check intervals ChangeTower's fastest interval is typically 15 minutes; OnChange supports 30s on Business and 10s on Enterprise. | ||
Visual (screenshot) diffs | ||
Text and content diffs | ||
CSS selector targeting | ||
API / JSON endpoint monitoring ChangeTower is a page-monitoring product; it does not diff JSON API responses natively. | ||
AI change summaries on every alert | ||
Causal attribution (Git commit correlation) OnChange ties every detected change to the commits that landed in the same window. | ||
WCAG accessibility scans | ||
Free public screenshot tool OnChange ships a free anonymous URL-to-PNG tool at /tools/screenshot. | ||
Slack / Discord alerts ChangeTower offers Slack on higher tiers; OnChange includes both on the free plan. | ||
Custom webhooks | ||
REST API for monitor lifecycle | ||
Team collaboration | ||
Change history retention OnChange: 90 days of full diff history on every plan. |
Comparison based on publicly available information. ChangeTower's feature set may have changed since publication; please verify on their website.
Pick OnChange if…
- You need sub-minute checks for pricing, inventory, or breaking API changes
- Your team monitors APIs (REST or JSON) alongside web pages
- You ship code and want to know which commit caused which downstream change
- You're an agency or in-house team with WCAG compliance obligations
- You want every alert channel (Slack, Discord, webhooks, email) on the free plan
- You want a clean REST API to provision monitors from CI/CD or IaC
Pick ChangeTower if…
- Your use case is purely marketing-focused visual monitoring on a handful of pages
- You already use ChangeTower's reporting workflow and prefer not to switch
- Hourly or 15-minute checks are good enough for your team
- You don't need API monitoring, accessibility scans, or commit-aware attribution
Pricing
ChangeTower's paid tiers start around $20/month and scale with monitor count and check frequency. OnChange Free is $0 with 5 full-feature monitors; Pro is $12/month for 50 monitors at 60-second intervals; Business is $39/month for 300 monitors at 30-second intervals. Every plan, including free, includes Slack, Discord, webhooks, API access, visual diffs, and AI summaries.
Migrating from ChangeTower
Export your ChangeTower monitor list, then recreate each monitor in OnChange using the same URL and CSS selector. Notification channels translate one-to-one (Slack, Discord, webhooks, email). Most teams finish migration in well under an hour, and OnChange's free plan covers the migration window so you can run both side by side.
Try OnChange free
5 monitors, every feature included, no credit card required. CancelChangeTowerwhenever you're ready.
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