Fifteen free uptime monitors would be notable on its own. What makes HetrixTools genuinely unusual is what sits beside them: blacklist monitoring that tells you when your IP or domain lands on a DNS blocklist. If you send email, that is the outage nobody notices until replies stop arriving — and almost no other monitoring tool watches for it.
From $5 a month · No check quotas · Set up in under a minute
Is HetrixTools worth it?
For anyone running their own servers or sending their own email, yes, and the free tier alone justifies an account. Fifteen uptime monitors, fifteen server monitors and blacklist monitoring for nothing is more than most competitors give away, and paid plans start at $5.95. The interface is plain and the product is aimed squarely at sysadmins rather than marketers, which suits its audience and will put others off.
HetrixTools covers three things: uptime monitoring of websites and services, server resource monitoring through a lightweight installed agent, and blacklist monitoring of IPs and domains against major DNS-based blocklists.
The free tier is the headline — 15 uptime monitors, 15 server monitors and blacklist monitoring, on a lifetime-free basis with four monitoring locations and email alerts. Paid plans start around $5.95 a month and add faster checks, more locations and more monitors.
Blacklist monitoring is what nothing else in this comparison offers. If your mail server IP gets listed on Spamhaus or a similar blocklist, your email quietly stops being delivered, and you generally find out from a customer rather than from a monitor.
Server-shaped monitoring, with a free tier that is not a teaser.
Alerts when an IP or domain appears on a major DNS blocklist. The failure mode it covers — email silently not arriving — is genuinely hard to detect any other way.
Plus 15 free server monitors, on a lifetime-free tier with four monitoring locations. Most competitors cap free accounts at five to ten.
CPU, RAM, disk and network through a lightweight agent, so the host is covered as well as the site.
Certificate and domain expiration tracking alongside the uptime checks rather than as a paid extra.
Fast checks available at a low price point, with instant downtime alerts.
Paid plans from around $5.95 a month, so the step up from free is small.
A free tier that most people will not outgrow quickly.
| Plan | Price/mo | Included | Notes |
|---|---|---|---|
| Free | $0 | 15 uptime, 15 server, blacklist monitors | 4 locations, email alerts, lifetime free |
| Paid | From $5.95 | More monitors, faster checks | More locations and alert channels |
| Higher tiers | From ~$9.95 | Larger allowances | Verify current tiers on their site |
Monitoring vendors change plan limits and prices frequently and without announcement. Every figure here carries a "verify on their site" caveat and you should take it seriously before making a decision on cost.
Two clear gaps on our side. We have no blacklist monitoring at all — if your mail IP gets listed, we will not notice, and HetrixTools will. We also have no server agent, so CPU, memory and disk are invisible to us; we only ever look from outside.
They also have a free tier and we do not. Fifteen uptime monitors for nothing is more than our $5 plan offers at its price, and for a personal server that is the better deal.
What we add is the watching of things rather than machines. Page content change detection, cron heartbeats, certificate warning windows configurable from 1 to 60 days and domain expiry from 1 to 180, with alerts when a certificate has already expired or when the check itself fails. That is a different set of questions from whether a server is healthy.
The honest split: your own servers, your own mail reputation, on a free tier — theirs. Sites, certificates, domains, pages and scheduled jobs watched from outside — ours. These two overlap less than the category suggests.
Every recorded change is compared word by word and kept with a before-and-after image. This is the real output, shown with worked example data.
Price fell from $49 to $39, and an annual discount was added.
The item is available again and the basket button returned.
A new subprocessor was added in another jurisdiction.
The free plan sends to one email address. Every paid plan adds the chat and webhook channels below, with 2 to 10 destinations depending on the plan. However many alerts you receive, the price does not change — nothing here is metered or charged per alert.
There are no voice calls and no SMS. If a phone call at 3am is a hard requirement, say so before you subscribe — we would rather tell you now than refund you later.
Yes, with a lifetime-free tier covering 15 uptime monitors, 15 server monitors and blacklist monitoring, with four monitoring locations and email alerts. Paid plans start from around $5.95 a month.
It checks whether your IP addresses or domains have been added to major DNS-based blocklists. That matters because a listed mail server IP means your email stops being delivered, usually without any error you would see.
Email delivery fails silently. Recipients do not get your messages and you get no bounce you would recognise, so the first sign is often a customer asking why you never replied. Almost no other monitoring tool checks for it.
Yes, certificate and domain expiration tracking is included alongside the uptime checks.
It reports CPU, RAM, disk and network usage from the machine itself. That covers the host rather than the website, which external checks cannot see.
Four on the free tier, with more available on paid plans. Fewer than the large enterprise platforms, which is consistent with the price.
No. It covers availability, server resources and blacklist status rather than what a page says.
They have blacklist monitoring, a server agent and a free tier, none of which we offer. We add page content change detection, cron heartbeats and configurable certificate and domain warning windows, all watched from outside your infrastructure.
Last updated August 2026 · Written by Amit Gupta, founder of MonitoringDaddy
HetrixTools is excellent for your own machines and mail reputation. We cover uptime, certificates, domains, page changes and heartbeats from $5 a month.