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Oh Dear
Capterra
4.9 (70)
G2
4.7 (31)

How is Oh Dear different from Nagios?

Nagios is the classic open-source monitoring veteran. Oh Dear takes a wider view: uptime plus SSL, DNS, full-site crawling, cron checks and Lighthouse, in one tool with one bill. Here's the honest comparison.

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Oh Dear vs Nagios
  • Bitmovin
  • HBO Nordic
  • Obsidian
  • Laravel
  • Fathom Analytics
  • PHP 8
  • Stanford University
  • Takeaway.com
  • IGN
  • VRT NWS
  • spatie
the quick verdict
Choose Oh Dear if you want uptime, SSL/TLS, DNS, full-site crawling, cron checks and Lighthouse in one place, with unlimited users and one predictable bill.
Choose Nagios if you want the battle-tested, plugin-driven classic and do not mind config files and manual upkeep.

What we have that Nagios doesn't

Hosted, zero maintenance

1. Hosted, zero maintenance

We run the servers, upgrades, probes and global checking locations. There is nothing to install, patch or babysit.

All-in-one, nothing to bolt on

2. All-in-one, nothing to bolt on

Uptime, SSL, DNS, full-site crawling, Lighthouse, cron and more are built in. No plugins, exporters or extra tools to assemble.

AI checks, crawl & Lighthouse

3. AI checks, crawl & Lighthouse

Natural-language AI checks, whole-site broken-link and mixed-content crawling, and real Lighthouse audits, none of which self-hosted monitors offer.

Oh Dear compared with Nagios

Oh Dear Nagios
Uptime monitoring? Yes Yes
Ping monitoring? Yes Yes
TCP port monitoring? Yes Yes
Performance monitoring? Yes Partial
Lighthouse audits? Yes No
Certificate health (SSL/TLS)? Yes Yes
Broken links & mixed content? Yes Partial
Sitemap monitoring? Yes Partial
DNS monitoring? Yes Yes
DNS blocklist monitoring? Yes Partial
Domain expiry monitoring? Yes Partial
Scheduled-task / cron? Yes Partial
Application health checks? Yes Partial
Port scanning? Yes Partial
AI-powered checks? Yes No
Notifications & integrations? Yes Yes
Status pages? Yes No
Single sign-on (SSO)? Yes No
Hosted & managed for you? Yes No
Zero setup & maintenance? Yes No
All-in-one, nothing to bolt on? Yes No
Entry price? €15 Free

Sourced from each vendor's docs · June 2026

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When Nagios is the better call

Battle-tested & plugin-driven

Best if you want the long-established standard with a huge plugin catalogue and are comfortable wiring it up and maintaining it via config files.

Weighing other tools?

See how Oh Dear compares across the board, or head-to-head against another monitor.

All comparisons vs Uptime Kuma vs Zabbix vs Icinga vs Prometheus vs Checkmk

Frequently asked questions

Target rings Target rings

Nagios is a good choice if you want open-source software you fully control and self-host, and you have the time and ops skills to install, configure, secure and maintain it. Choose it when control and zero licensing cost outweigh the setup and upkeep.

Oh Dear is fully hosted with nothing to run or maintain, and includes website-specific checks self-hosted tools lack out of the box: AI-powered checks, full-site broken-link and mixed-content crawling, sitemap monitoring, real Lighthouse audits and public status pages, all in one place.

The software is free, but you pay in servers, setup, upgrades, security patching and the engineering time to keep it running, plus the risk that your monitoring goes down together with your own infrastructure. Oh Dear runs independently of your stack from €10/month.
See all other FAQ items →

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Not convinced yet? Need help?
Get in touch via [email protected].