Know When Something
Important Changes Online
Most monitoring tools drown you in alerts every time a timestamp or ad rotates. SignalWhen uses AI to filter out the noise — you only hear about changes that actually matter.
How It Works
Three simple steps to start monitoring anything.
Choose what to monitor — a webpage, API endpoint, RSS feed, or server uptime.
On every check, our AI analyzes what changed and filters out noise — timestamps, ads, session tokens — so only meaningful changes reach you.
Receive instant alerts via email, Slack, webhooks, or SMS when something changes.
Other tools tell you something changed.
We tell you when something important changed.
Competitors alert on every DOM change. Our AI understands context — it knows a rotating ad isn't a price drop.
Stop juggling Distill + UptimeRobot + a feed reader. Monitor websites, APIs, feeds, and uptime in one place.
JSON API monitoring with JSONPath, webhooks, and Slack. Built by developers, for developers.
What Can You Monitor?
Four powerful signal types to cover any monitoring need.
AI detects meaningful content changes — like price drops or status updates — while ignoring timestamps, ads, and other noise.
Monitor your servers and services. Know instantly when they go down — or come back up.
Watch RSS and Atom feeds for new items. Stay on top of blogs, news, and releases.
Monitor any JSON API endpoint. Track specific fields and get alerted on value changes.
Real-World Use Cases
See how AI-powered noise reduction works across different monitoring scenarios.
AI ignores cosmetic page updates and only alerts you when a real price change happens. Never miss a deal again.
Know when your website or API goes down before your customers do. AI confirms real outages so you skip false alarms.
Follow blogs, news sites, and RSS feeds. AI summarizes what changed so you know at a glance whether it matters.
Track any JSON endpoint. AI filters out routine fluctuations and alerts you only on significant data shifts.
See What You'll Receive
Real examples of AI-powered notifications — no noise, just the changes that matter.
Price changed from $899 to $749 — a $150 drop (17% off the previous listed price).
Service recovered after 12 min downtime. Status changed from HTTP 503 to HTTP 200. Current response time: 142ms.
Vercel announced Edge Middleware v2 with breaking changes to the routing API. Includes migration guide and 30-day deprecation window for v1.
The rates.EUR field changed from 1.0842 to 1.1064 (+2.05%), crossing your configured 2% threshold.
Simple, Transparent Pricing
Start free, upgrade when you're ready.
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AI-powered change detection
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Email notifications
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1-hour check interval
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All Free features
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Webhook notifications
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30-minute check interval
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All Starter features
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Slack notifications
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15-minute check interval
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All Pro features
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5-minute check interval
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365-day history
Start Monitoring For Free
Start with 3 free signals — AI filtering included. No credit card required.