A monitor for what you are building, free

A handful of hosts, mostly on Free or Pro: an API you're building, a personal domain, a cron job that should not go quiet. hostnag mints a ping URL for the heartbeat and watches the rest from the cloud.

Start free

The plan that fits: Free.

What Developers watch
What breaks	hostnag
A host goes downwebsite, API, VPN, mail, gateway	Yes
A certificate expiresdays-before thresholds, daily inside the last window	Yes
A domain lapsesregistration expiry from RDAP	Yes
A scheduled job stops runningcron, backups, workers: a heartbeat that goes quiet	Yes

The board

The overview over sample data. Press LAMP TEST; switch the view.

Active06

Alarm: 01
Supervisory: 02
Trouble: 00
Normal: 03
Unlit: 00

View

Acme Retail

06Sample data

DownHTTP

Checkout API

api.acme.example/health

Down47 min

checked 1 min ago

Expiring soonCert

mail.example.com

11d left10 Oct 2026

checked 40 min ago

UpTCP

VPN gateway

vpn.office.example

31ms

checked 2 min ago

OKDomain

example.com

40d left08 Nov 2026

checked 9 h ago

UpDNS

MX example.com

example.com

18ms

checked 4 min ago

DegradedHTTP

Storefront

shop.acme.example

1840msslow for 22 min

checked 1 min ago

How it is set up

01
Add the host
A URL for the app, or a host and port for anything else: a database, a game server, a personal domain.
02
Mint a ping URL for whatever runs on a schedule
A cron run or a backup calls the URL when it finishes. Silence past the deadline is the alert.
03
Get told by email
Email alerts are on every plan, Free included.
04
Watch the certificate and the domain too
The same host can carry a certificate monitor and a domain registration monitor beside its uptime monitor.

The plan that fits

Monitors: 20
More monitors: None
Groups: 3
Seats: 3
Locations: 1
Fastest interval: 5 min
Channels: Email, Slack, Discord, Microsoft Teams, Telegram, Webhook
History: 30 days
Reports: none
Scoped viewers: No

Questions

Is there a plan with no cost to start?

Yes. Every new organization starts with 14 days of Pro, no card, and then the Free plan: 20 monitors in 3 groups, alerts by email, Slack, Discord, Teams, Telegram and webhook, one status page, checks every 5 minutes from one location.

What happens when I outgrow the Free plan?

Move to a paid plan for more monitors, more locations, more channels and longer history, from the billing page. Nothing is deleted and the monitors keep running.

Features that matter

Uptime monitoringWebsites, APIs and anything that answers on a port, checked every minute from up to five places, with a failure confirmed before anyone is paged.Heartbeat monitoringA minted URL for each job that runs on its own schedule, and an alert when a run does not call it in time.Certificate monitoringEvery certificate hostnag can reach is watched for expiry, a swapped chain and a renewal that should already have happened; the ones it cannot reach get a URL to report to instead.Domain monitoringEvery domain's registration watched for lapsing, a registry hold or a blocked renewal, plus whether its nameservers answer for it and agree, and whether its DNSSEC signatures are still fresh.Discovery and subdomain watchEvery name under a domain, found in its own DNS, its homepage and the names people usually use, each judged live, gone or pointing nowhere, with the ones anyone could claim listed first. A subdomain watch looks again every day and alerts on what changed.

Add a host. Hear about it first.

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