Every free synthetic check tier that clears our bar in 2026: 5 offers meet the criteria and 4 offers are demoted with a named reason. Our membership test: runs a check you author — a scripted browser session, a multi-step API call, or an assertion on a response body — on a schedule from outside your infrastructure, and reports whether the behaviour it asserts still holds. We could not confirm today's terms for 4 of them, and on all 4 our own read did not confirm them. Each row says why.
Automated API testing and monitoring. Free plans for teams and individuals.
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://assertible.com, where it says: “With Assertible, you can run your API tests against any environment, like staging or production .”. How we use this
Full-stack observability platform — free forever plan: 100 GB/month data (APM, logs, infrastructure, traces, RUM, synthetics, database, serverless), 1,000 RUM sessions/month, 20,000 synthetic checks/month, 14-day data retention, unlimited users
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://middleware.io/pricing/, where it says: “OpsAI SRE Agent Detect, debug & auto-fix issues Synthetic Monitoring Test APIs & prevent outages Browser Testing Test web apps”. How we use this
Cron job and uptime monitoring — free Hacker plan: 5 monitors, 5-minute check frequency, email, Slack, and webhook alerts, 1 status page (50 subscribers), 12-month data retention, single user. When we last read the page we cite for this offer, on 2026-11-01, we found a change we could not reconcile with the terms we publish, so we cannot confirm these terms today.
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://cronitor.io/pricing, where it says: “events free $10 /mo per 100,000 events Custom Synthetic browser checks × $1 /mo per 1,000 checks Custom Fastest check”. How we use this
Full observability platform — 100 GB data ingest/month, 1 full platform user, unlimited basic users, 500 synthetic checks, 8+ days retention
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://newrelic.com/pricing, where it says: “Additional synthetics checks beyond the amount included in your edition are available at $0.005 per check.”. How we use this
Always Free: all non-chargeable Google Cloud metrics, first 1M monitoring API calls/month. Dashboards, alerting, and uptime checks for GCP resources. When we last read the page we cite for this offer, on 2026-10-25, we found the same terms as an earlier read we had declined to record, so we cannot confirm these terms today.
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://cloud.google.com/monitoring/pricing, where it says: “Execution of Monitoring Synthetic Monitors $1.20/1,000 executions”. How we use this
Uptime and status page monitoring — free plan: 3 monitors (uptime, keyword, heartbeat), 3-minute check interval, 2 team members, 1 status page, SSL monitoring, multi-location checks, email/Slack/Discord alerts
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://onlineornot.com/pricing, where it says: “Monitoring Heartbeat Monitoring Website Monitoring Synthetic monitoring Status Pages Pricing Changelog Support Schedule a demo”. How we use this
Netdata is an open-source tool to collect real-time metrics. It's a growing product and can also be found on GitHub! When we last read the page we cite for this offer, on 2026-10-24, we could read no amount, tier or rate on the page, so we cannot confirm these terms today.
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://www.netdata.cloud/, where it says: “Infrastructure Monitoring Container Monitoring Synthetic Checks Application Performance Database Monitoring Troubleshooting”. How we use this
Observability platform — Logs: 500 MB/day ingestion, 7-day retention. Monitoring: 3 hosts, 3 containers/host, 30-min data retention, 1 alert rule. Volume-based pricing, no per-host charges on paid plans
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://sematext.com/pricing, where it says: “Start free trial Synthetics Monitor performance and availability of your site and APIs.”. How we use this
Superseded: As of 2026-08-28, xitoring.com reads: The page offers a 14-day free trial, and then paid plans starting at $4.99/mo for Uptime + SSL. We are not publishing our stored Xitoring.com terms beside it — our own pricing change record, discovered 2026-08-28, names them as the previous ones. Read what we recorded ↓
Listed in Monitoring, and on this page because we labelled it synthetic_check. We read that on 2026-09-01 from https://xitoring.com/, where it says: “Uptime & Synthetic Multi-protocol checks from 15+ global nodes.”. How we use this
| Vendor | Free Tier | Key Limits | Durability | Read / catalogue date |
|---|---|---|---|---|
| assertible.com | Free | Automated API testing and monitoring. Free plans for teams and individuals. | stable | 2026-11-04 |
| Middleware.io | Free | Full-stack observability platform — free forever plan: 100 GB/month data (APM, logs, infrastructure, traces, RUM, synthe... | watch effective 2026-05-03 |
2026-10-26 |
| Cronitor | Hacker | Cron job and uptime monitoring — free Hacker plan: 5 monitors, 5-minute check frequency, email, Slack, and webhook alert... | not published read not reconciled · 2026-11-01 |
2026-11-01 / 2026-08-18 |
| New Relic | Free | Full observability platform — 100 GB data ingest/month, 1 full platform user, unlimited basic users, 500 synthetic check... | stable | 2026-10-24 |
| Google Cloud Monitoring | Always Free | Always Free: all non-chargeable Google Cloud metrics, first 1M monitoring API calls/month. Dashboards, alerting, and upt... | not published change not established · 2026-10-25 |
2026-10-25 / 2026-08-18 |
We publish no ranking of these. Nothing we record measures popularity or generosity, so naming a best or a top few would be our preference rather than our data. We hold 5 free synthetic check offers that clear our bar, each listed with the terms we publish and the date we last read them. Our ranking rule is published at /criteria.
5 offers meet our criteria on this page. Of those, 2 carry no recorded change to the terms we publish, 1 a recorded narrowing, and we publish no durability signal for 2. The Durability column below says which offer is in which group, and links the dated record behind every change. We withhold the class where the pricing page does not resolve or states no amount, tier or rate we can read, where we refused the last read, where the listing is gated, or where a narrowing in our records cites no source or no archived copy of the vendor's page has confirmed it. We do not rank these by how much you get, because the limits are not comparable without reading each vendor's page.