SignalWatch

SignalWatch is an API-first platform that monitors public URLs for content changes and downtime, sending real-time webhook alerts with detailed diffs of what changed. It allows users to point CSS selectors at specific page elements (like pricing or status indicators), filter out noise with regex patterns, and set minimum change thresholds to avoid unnecessary notifications.

The platform supports multiple notification channels including email, Slack, Discord, and signed JSON webhooks, making it easy to integrate with existing workflows and automation tools like n8n or CI/CD pipelines. Use cases include monitoring competitor pricing pages, status pages, changelogs, and any other public web content that requires change detection.

SignalWatch offers flexible plans from a free tier with 3 monitors checked every 15 minutes, up to enterprise options with 500 monitors and 2-minute check intervals. The service includes 45-day history, change/down/recovery event tracking, and a 14-day refund guarantee on first payment.