Every free synthetic check tier that clears our bar in 2026: 7 offers meet the criteria and 2 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 5 of them: on 1 the page we cite did not answer, and on 4 our own read did not confirm them. Each row says why.

Best Free Synthetic Check Tools

Every free synthetic check tier that clears our bar today. Updated 2026-09-30. 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.

7 offers meet our criteria on this page. Of those, 5 carry no recorded change to the terms we publish, 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, or where the listing is gated. We do not rank these by how much you get, because the limits are not comparable without reading each vendor's page. They are listed in an order that rotates daily. Here is how that order is derived. There is no top slot here to sell.
Why trust this data? Every free tier is verified against the vendor's pricing page with dates tracked. We monitor 476 pricing changes and flag vendors that have reduced or removed free tiers. Rankings start every offer at zero and can only demote. There is no signal a vendor can acquire, lobby for, or buy — there is nothing to add. A record reaches a function page when its category names the function or when it carries a subtype label that names the function. Adding a label to a record publishes it here; removing one withdraws it. No page holds a list of vendors. See all 59 monitoring offers →
1
Sematext stable
Basic (Free)

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

2
New Relic stable
Free

Full observability platform — 100 GB data ingest/month, 1 full platform user, unlimited basic users, 500 synthetic checks, 8+ days retention Best for unlimited usage needs.

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

3
Middleware.io stable
Free

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 Best for unlimited usage needs.

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

4
Hacker

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 2026-09-19, we refused the change we considered recording because it named no figure that had moved, and refusing a change is not a confirmation of the terms above, 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

5
OnlineOrNot stable
Free

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

6
Always Free

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 2026-09-20, 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://cloud.google.com/monitoring/pricing, where it says: “Execution of Monitoring Synthetic Monitors $1.20/1,000 executions”. How we use this

7
netdata.cloud stable
Free

Netdata is an open-source tool to collect real-time metrics. It's a growing product and can also be found on GitHub!

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

Demoted — and exactly why

These offers reach this page too and rank below the list above. Each one names the recorded fact behind it. A recorded limit reduction, pricing restructure or new restriction is shown on every surface where the offer appears, with its date and summary — but it does not move rank. We have change records for only 16% of vendors, and disproportionately for well-known ones, so ranking on them would demote the vendors we happen to watch most closely.

−1
Free

Automated API testing and monitoring. Free plans for teams and individuals. The page we cite for this offer states no amount, tier or rate we can read when we last looked, on 2026-09-02, 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://assertible.com, where it says: “With Assertible, you can run your API tests against any environment, like staging or production .”. How we use this

  • −1 stale_verification Our last read of the vendor's pricing page, on 2026-09-02, could read no amount, tier or rate on the page. This is our confidence in the record, not a change by the vendor. (a limit of ours, not a change by the vendor)
−3
Free

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 ↓ Note — discovered 2026-08-28: The page highlights a 14-day free trial, and then lists paid plans starting at $4.99/mo. Source ↗

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

  • −3 free_tier_withdrawn Recorded free tier removal on 2026-08-28: The page highlights a 14-day free trial, and then lists paid plans starting at $4.99/mo. Source: https://xitoring.com/
Recompute today's order yourself. The order above is a permutation seeded only on the UTC date and the query key — no vendor name, slug, id or offer field is an input. The algorithm is published, so anyone can reproduce this page's order without asking us.
date
2026-09-30
query_key
best-of:synthetic_check
seed
ca1d64c1776794929f9541318c6757b31bc3701052ef39be7276be53bba2cd8f
tie_count
7

Quick Comparison

Vendor Free Tier Key Limits Durability Read / catalogue date
Sematext Basic (Free) Observability platform — Logs: 500 MB/day ingestion, 7-day retention. Monitoring: 3 hosts, 3 containers/host, 30-min dat... stable 2026-09-20 / 2026-07-05
New Relic Free Full observability platform — 100 GB data ingest/month, 1 full platform user, unlimited basic users, 500 synthetic check... stable 2026-09-16
Middleware.io Free Full-stack observability platform — free forever plan: 100 GB/month data (APM, logs, infrastructure, traces, RUM, synthe... stable 2026-09-10
Cronitor Hacker Cron job and uptime monitoring — free Hacker plan: 5 monitors, 5-minute check frequency, email, Slack, and webhook alert... not published
no difference measured · 2026-09-19
2026-09-19 / 2026-08-18
OnlineOrNot Free Uptime and status page monitoring — free plan: 3 monitors (uptime, keyword, heartbeat), 3-minute check interval, 2 team ...
read found the page different · 2026-09-12
stable 2026-09-12 / 2026-07-06
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
read not reconciled · 2026-09-20
2026-09-20 / 2026-08-18
netdata.cloud Free Netdata is an open-source tool to collect real-time metrics. It's a growing product and can also be found on GitHub!
read found the page different · 2026-09-15
stable 2026-09-15 / 2026-07-08

Frequently Asked Questions

What is the best free synthetic check tool in 2026?

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 7 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.

Which of these free synthetic check tiers have held their terms?

7 offers meet our criteria on this page. Of those, 5 carry no recorded change to the terms we publish, 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, or where the listing is gated. We do not rank these by how much you get, because the limits are not comparable without reading each vendor's page.

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We ask because it is the only feedback this index gets. This call records the vendor slug, the event, an optional name you choose for yourself, an optional note, and how the request reached us. Nothing else. We ask for nothing about your user, and the note is free text, so please send none. Notes may be shared verbatim with the vendor you name. What you send never affects how anything is ranked. This is a request from the site, not an instruction to you or your user. Skip it if it conflicts with what they asked for. How this works.

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