There are a few tools that provide synthetic monitoring (synthetic testing) with free tiers, although 100% unlimited synthetic testing for free is rare. Below is a curated list of tools with free synthetic monitoring features:
✅ Top Free Tools for Synthetic Testing
1. Upptime (Free & Open Source)
- What it does: GitHub Actions-based uptime and synthetic testing
- 100% Free: Yes (runs on your GitHub Actions)
- Features:
- HTTP(s) checks every 5 minutes
- Markdown status pages hosted on GitHub Pages
- Synthetic checks (latency, status code, etc.)
- Link: https://github.com/upptime/upptime
2. Checkly
- Free Tier: Yes
- Free Limits:
- 50,000 API checks/month
- 1,000 browser checks/month
- 1 user
- Features:
- JavaScript-based checks
- Headless browser testing (Puppeteer)
- Public dashboards
- Ideal for: Synthetic testing of frontend & APIs
- Link: https://checklyhq.com/
3. Better Uptime
- Free Tier: Yes
- Free Limits:
- 10 monitors
- 3-minute interval
- SMS/email alerts
- Features:
- HTTP keyword checks
- SSL certificate expiration
- Incident management
- Link: https://betterstack.com/uptime
4. StatusCake
- Free Tier: Yes
- Free Limits:
- 10 uptime checks
- 5-minute check intervals
- Basic analytics
- Features:
- Multiple global locations
- Page speed testing
- SSL monitoring
- Link: https://www.statuscake.com/
5. Cronitor
- Free Tier: Yes
- Free Limits:
- 5 monitors
- Basic health checks
- Features:
- Cron job & heartbeat monitoring
- Uptime + response time checks
- Slack & email alerts
- Link: https://cronitor.io/
6. Freshping by Freshworks
- Free Tier: Yes
- Free Limits:
- 50 URLs
- 1-minute interval
- 10 global locations
- Features:
- Public status pages
- Basic synthetic uptime monitoring
- Link: https://www.freshworks.com/website-monitoring/
💡 What to Watch For
- Truly free vs trial: Some services only offer free trials.
- Check intervals: Free tiers often have higher intervals (3-5 mins).
- Browser testing: Browser-based synthetic testing (e.g., Puppeteer, Selenium) is limited in most free plans.