Choosing a website monitoring tool usually comes down to one question: how much visibility do you need, and how much are you willing to pay for it? Sentinel vs Pingdom is a comparison between two very different approaches to that question. Sentinel is a newer monitoring platform built around a genuinely free entry tier covering uptime, SSL, DNS, domain expiry and heartbeat checks. Pingdom, now part of SolarWinds, is an established synthetic and real-user monitoring platform aimed at teams that need deeper performance data and are prepared to pay from day one. Neither tool is a straight upgrade on the other — they serve different budgets and different monitoring depths. This article compares both on their current, publicly documented plans so you can see where each one actually fits.
Sentinel vs Pingdom at a Glance
| Category | Sentinel (Free) | Pingdom |
|---|---|---|
| Free plan | Yes — permanent, £0/month | No permanent free plan; 14-day free trial |
| Uptime monitoring | Included | Included (core product) |
| SSL monitoring | Included | Included (via HTTPS uptime checks) |
| DNS monitoring | Included | Not publicly confirmed as a dedicated feature |
| Domain expiry monitoring | Included | Not publicly confirmed as a dedicated feature |
| Heartbeat monitoring | Included | Not offered |
| Minimum polling interval | 5 minutes (Free); 30–60 seconds on paid plans | As frequent as 1 minute (paid plans) |
| Historical data retention | 7 days (Free), 30 days (Individual), 90 days (Team), 365 days (Agency) | Up to 400 days depending on plan |
| Incident management | Not included in Free; included on all paid plans (Individual, Team, Agency) | Not a core built-in feature |
| Maintenance windows | Not included in Free; included on all paid plans (Individual, Team, Agency) | Supported |
| Status pages | Not included in Free; included on all paid plans (Individual, Team, Agency) | Included (one public status page per account) |
| Teams | 1 login user, 1 notification user (Free); up to 25 users and 50 notification contacts on Agency | Multi-user support on paid plans |
| Best suited to | Early-stage projects, solo developers, budget-conscious teams and agencies | Teams needing synthetic/real-user performance monitoring at scale |
What Is Sentinel?
Sentinel is a website and infrastructure monitoring platform from Elbah Group. It covers the core checks most sites and services need to catch problems early: uptime, SSL certificate validity, DNS resolution, domain expiry, and heartbeat monitoring for scheduled jobs and background processes. Its Free plan is a permanent tier rather than a time-limited trial, giving small projects a genuine way to monitor critical infrastructure without a subscription. Three paid tiers sit above it — Individual (£12/month), Team (£30/month) and Agency (£65/month) — adding more monitors, more users, faster polling and extra alert channels; all three paid tiers also include incident management, maintenance windows and public status pages, which are the main features the Free plan lacks.
What Is Pingdom?
Pingdom, owned by SolarWinds, is one of the longer-standing names in website performance and uptime monitoring. It combines synthetic monitoring — scripted checks run from global probe locations — with real user monitoring (RUM), which measures how actual visitors experience page load times. Pingdom’s synthetic monitoring plans scale from a handful of uptime checks up to tens of thousands, with page speed testing and multi-step transaction monitoring available on higher tiers. It’s positioned as a performance and availability platform for teams that want detailed diagnostics on how a site behaves in the real world, not just whether it’s up.
Sentinel Free vs Pingdom Free/Trial
| Feature | Sentinel Free | Pingdom Free/Trial |
|---|---|---|
| Price | £0/month, ongoing | No permanent free tier; 14-day free trial (credit card terms vary by source) |
| Monitors | 3 | Not applicable — no free tier; trial access mirrors paid plan limits |
| Login users | 1 | Not publicly confirmed for trial |
| Notification users | 1 | Not publicly confirmed for trial |
| Minimum polling interval | 5 minutes | 1 minute (standard on paid plans; trial likely matches) |
| Historical data retention | 7 days | Not applicable during a 14-day trial |
| Monitoring types | Uptime, SSL, DNS, domain expiry, heartbeat | Uptime and SSL (via HTTPS checks); no confirmed DNS, domain expiry or heartbeat monitoring |
The core difference is structural: Sentinel’s Free plan is a permanent product tier, while Pingdom requires payment after a 14-day evaluation period. If your priority is trying a tool with no long-term cost, Sentinel’s Free plan is worth a look — try Sentinel free and monitor up to three endpoints with no expiry date on the plan itself.
Uptime Monitoring
Both platforms treat uptime monitoring as their foundation. Sentinel Free checks are limited to a 5-minute minimum polling interval across up to 3 monitors, with 7 days of historical data retained. Pingdom’s paid plans support checks as frequent as every 1 minute, which will catch shorter outages that a 5-minute interval could miss, and retain history for up to 400 days on higher tiers. For teams that need to detect brief blips and keep long-term uptime records for SLA reporting, Pingdom’s paid tiers offer more resolution and depth. For teams that mainly need to know within a few minutes if a site is down, Sentinel’s interval is adequate and costs nothing.
SSL Monitoring
Sentinel includes SSL certificate monitoring as a standard check type in its Free plan, alerting on certificate issues and expiry. Pingdom handles SSL monitoring by enabling HTTPS on an uptime check, which then tracks certificate validity and warns ahead of expiration — configurable from a day to a month in advance. Functionally the outcome is similar on both platforms: certificate expiry gets flagged before it causes an outage. Sentinel treats SSL as a distinct, dedicated monitor type from the outset; Pingdom folds it into its uptime check configuration.
DNS Monitoring
Sentinel Free includes DNS monitoring as one of its five built-in check types. Pingdom does not appear to offer dedicated DNS monitoring as a named, standalone feature — its public documentation and product pages focus on uptime, page speed and transaction checks, with no confirmed DNS-specific monitor type. If DNS resolution monitoring is a requirement, this is a point in Sentinel’s favour, though teams should verify current Pingdom capabilities directly with SolarWinds before ruling it out entirely.
Domain Expiry Monitoring
The same pattern holds for domain expiry. Sentinel includes domain expiry monitoring in its Free plan as standard. Pingdom’s public materials do not confirm a dedicated domain expiry monitoring feature; this is generally the domain of specialist tools rather than Pingdom’s core synthetic/RUM offering. Teams relying on Pingdom for domain expiry tracking should confirm this directly, as it is not publicly documented as a supported check type.
Heartbeat Monitoring
Sentinel Free includes heartbeat monitoring, useful for confirming that cron jobs, scheduled tasks and background processes check in on schedule. Pingdom does not offer heartbeat or cron job monitoring — it is built around external, outside-in synthetic checks rather than passive check-ins from internal processes. Teams needing to monitor scheduled jobs alongside their website will need a separate tool if using Pingdom, whereas Sentinel covers this in its base Free tier.
Alerts and Integrations
Pingdom’s paid plans support email and SMS alerting, with SMS allowances built into pricing tiers. Sentinel’s Free plan supports 1 notification user with no confirmed alert channel beyond email; its paid tiers expand this significantly — Individual adds Discord alongside a 500/month email limit, Team adds Microsoft Teams and Slack with a 5,000/month email limit, and Agency adds 250 call credits and 250 SMS credits on top of a 25,000/month email limit. It’s worth distinguishing what a product supports generally from what’s actually unlocked on a free or entry tier — Pingdom’s alerting is a paid-plan feature from the outset, since there’s no permanent free tier to compare against.
Incident Management and Maintenance Windows
Sentinel’s Free plan does not include incident management or maintenance windows — both are disabled at this tier. All of Sentinel’s paid plans — Individual (£12/month), Team (£30/month) and Agency (£65/month) — include incident management and maintenance windows as standard. Pingdom also supports maintenance windows on its monitoring plans, allowing checks to be paused during planned downtime, though formal incident management (timelines, postmortems, on-call escalation) is not confirmed as a core built-in feature of Pingdom based on public documentation. If maintenance windows are a hard requirement on a free plan today, Pingdom’s trial currently supports this where Sentinel Free does not — but any Sentinel paid tier closes that gap.
Status Pages
Sentinel Free does not include public status pages — this is disabled at the free tier, but all of Sentinel’s paid plans (Individual, Team and Agency) include public status pages as standard. Pingdom includes one public status page per account as part of its monitoring plans, with basic branding options (standard or custom template, custom domain support) and a hard limit of one status page per organisation, with no password protection available. For teams on Sentinel’s Free plan that need to communicate uptime status publicly right away, Pingdom’s trial currently has the documented advantage — but the gap disappears as soon as a team moves to any Sentinel paid tier.
Teams and Agencies
Sentinel Free is scoped to a single login user and a single notification user, making it a fit for solo developers or single-site projects rather than teams. Its paid tiers scale this up directly: Individual allows 1 login user and 2 notification contacts, Team allows 10 login users and 20 notification contacts, and Agency allows 25 login users and 50 notification contacts, alongside 20, 100 and 250 monitors respectively. Pingdom’s paid plans also support multiple users, which suits agencies and teams managing monitoring across several stakeholders or clients. Agencies managing multiple client sites with shared visibility needs should weigh Sentinel’s Agency tier — 250 monitors, 25 users, 50 notification contacts for £65/month — against Pingdom’s multi-user tiers on actual requirements.
Sentinel vs Pingdom Pricing
Pingdom’s published entry pricing for Synthetic Monitoring starts at around $10–15/month (billed annually or monthly respectively) for 10 uptime monitors and 1 advanced monitor, with Real User Monitoring starting at a similar price point for 100,000 page views. Higher Pingdom tiers scale up in monitor count and features, reportedly reaching into the hundreds of dollars per month for Professional-level access. Sentinel’s Free plan costs £0/month for 3 monitors with the limitations described above, and its paid tiers are published as follows:
| Free | Individual | Team | Agency | |
|---|---|---|---|---|
| Price | £0/month | £12/month (7-day free trial) | £30/month | £65/month |
| Monitors | 3 | 20 | 100 | 250 |
| Login users | 1 | 1 | 10 | 25 |
| Notification contacts | 1 | 2 | 20 | 50 |
| Min. polling | 5 minutes | 60 seconds | 60 seconds | 30 seconds |
| Monitoring | Uptime, SSL, DNS, domain expiry, heartbeat | Domain and SSL monitoring (without detailed history) | DNS monitoring, Domain and SSL monitoring (full) | DNS monitoring, Domain and SSL monitoring (full) |
| Alerts | Not publicly confirmed beyond email | Email (500/month), Discord | Email (5,000/month), Discord, Microsoft Teams, Slack | Email (25,000/month), Discord, Microsoft Teams, Slack, Calls (250 credits), SMS (250 credits) |
| Historical data | 7 days | 30 days | 90 days | 365 days |
Uptime and heartbeat monitoring, included on the Free plan, continue through every paid tier — the pricing page’s plan comparison calls out Domain, SSL and DNS monitoring specifically because those are what scale with each tier, not because uptime or heartbeat checks are dropped on upgrade. Incident management, maintenance windows and public status pages are also included as standard across all three paid tiers — the only plan without them is Free. Annual pricing/discounts are not published on Sentinel’s pricing page. Historical data retention on paid plans is 30 days on Individual, 90 days on Team, and 365 days on Agency.
In practical terms: a free/early-stage project with three or fewer things to monitor and no need for status pages or incident management can run entirely on Sentinel Free at no cost. A solo developer needing more monitors and faster polling can move to Individual at £12/month; a small team needing shared logins and broader alerting fits Team at £30/month; and an agency managing multiple clients with call/SMS escalation fits Agency at £65/month — all considerably below Pingdom’s $10–15/month entry price once monitor counts and user seats are factored in, though Pingdom’s real user monitoring and longer confirmed data retention remain unmatched at any Sentinel tier.
Where Pingdom Is Better
Pingdom has clear strengths that Sentinel’s Free plan does not match. Its real user monitoring and synthetic transaction/page speed testing go beyond simple uptime checks, giving teams insight into actual visitor experience — a capability Sentinel’s product data doesn’t claim to offer. Polling as frequent as 1 minute catches shorter outages than Sentinel Free’s 5-minute minimum. Data retention up to 400 days supports long-term SLA and trend reporting far beyond Sentinel Free’s 7 days. Pingdom also offers status pages and maintenance windows on its trial without requiring an upgrade — Sentinel’s Free plan needs a paid tier to unlock the same three features — plus the maturity of being a long-established, SolarWinds-backed product with a large global probe network. For teams that need performance monitoring depth or enterprise-grade infrastructure now, Pingdom is the stronger choice.
Where Sentinel Is Better
Sentinel’s core advantage is accessibility: a genuinely free, permanent plan with no trial expiry, covering five distinct monitoring types — uptime, SSL, DNS, domain expiry and heartbeat — in one tool, backed by paid tiers priced well below Pingdom’s entry point once a team outgrows Free. Pingdom has no permanent free tier at all, only a 14-day trial, meaning any ongoing use requires payment from the outset. Sentinel Free also includes DNS and heartbeat monitoring, which are not confirmed as available on Pingdom at any tier. For anyone wanting to monitor a small number of endpoints without committing to a subscription, or to scale up affordably afterwards, Sentinel is the more accessible option.
Who Should Choose Sentinel?
- Running a small number of sites or services (3 or fewer monitors) and want a genuinely free option
- Need DNS, domain expiry, or heartbeat monitoring alongside uptime and SSL, in one place
- Working solo or on a small side project without a team monitoring workflow
- Are happy on the Free plan without status pages, incident management, or maintenance windows — all three are included once you move to any paid tier
- Prefer a permanent free tier over a time-limited trial, with an affordable upgrade path (£12–£65/month) as needs grow
Who Should Choose Pingdom?
- Need real user monitoring or synthetic transaction/page speed testing, not just uptime checks
- Require sub-minute polling intervals to catch brief outages
- Need long-term historical data retention (months, not days) for reporting or SLAs
- Want a public status page or maintenance windows available immediately
- Are managing monitoring across a team and need multi-user support
- Are prepared to pay from the outset in exchange for a mature, established platform
Sentinel vs Pingdom: Which Should You Choose?
Choose Pingdom when performance depth matters most — real user monitoring, synthetic transaction testing, sub-minute polling, long data retention, and status pages available today, and you’re prepared to pay from the start. Choose Sentinel when accessibility matters most — a genuinely free tier that covers uptime, SSL, DNS, domain expiry and heartbeat monitoring for a small number of endpoints, with no trial clock running, and an affordable paid path if you outgrow it. Neither is a wholesale replacement for the other at this stage; the honest comparison is between Pingdom’s paid depth and Sentinel’s free breadth plus lower-cost paid tiers. Teams that outgrow Sentinel’s Free plan can step up to Individual, Team or Agency at £12, £30 and £65/month respectively — worth weighing directly against Pingdom’s confirmed pricing before committing either way. If you want to see where Sentinel fits for your own setup, try Sentinel free — it takes a few minutes to add your first monitors and costs nothing to run.
Related Comparisons
For a broader look at how Sentinel compares across the market, see our guide to the Best Uptime Monitoring Tools & Sentinel Alternatives.
- Sentinel vs UptimeRobot — a closer look if you’re weighing Sentinel against another budget-friendly, free-tier-first monitoring tool.
- Sentinel vs StatusCake — worth reading if status pages and multi-region checks matter as much as uptime alerts.
Frequently Asked Questions
Is Sentinel free?
Yes. Sentinel’s Free plan is £0/month, permanently, covering up to 3 monitors with uptime, SSL, DNS, domain expiry and heartbeat checks, a 5-minute minimum polling interval, and 7 days of historical data. Paid plans start at £12/month for individuals, £30/month for small teams, and £65/month for agencies.
Does Pingdom have a free plan?
No. Pingdom does not currently offer a permanent free plan — it offers a 14-day free trial, after which continued use requires a paid subscription.
Is Sentinel a good alternative to Pingdom?
For small projects needing basic uptime, SSL, DNS, domain expiry and heartbeat checks at no cost, Sentinel is a reasonable alternative, and its paid tiers (£12–£65/month) undercut Pingdom’s entry pricing for teams that outgrow the Free plan. For teams needing real user monitoring, synthetic transaction testing, or enterprise-scale monitoring, Pingdom’s paid plans offer capabilities Sentinel does not.
Does Sentinel monitor SSL certificates?
Yes. SSL monitoring is included in Sentinel’s Free plan as a standard, dedicated check type, and full SSL history is included on the Team and Agency paid plans.
Does Sentinel support heartbeat monitoring?
Yes. Heartbeat monitoring, for tracking scheduled jobs and background processes, is included in Sentinel’s Free plan and continues on every paid tier. Pingdom does not currently offer this feature.
What is Sentinel’s minimum polling interval?
5 minutes on the Free plan, dropping to 60 seconds on the Individual and Team plans and 30 seconds on Agency. Pingdom supports checks as frequent as 1 minute on its paid plans.
How many monitors does Sentinel Free include?
Up to 3 monitors, with 1 login user and 1 notification user. Paid plans scale to 20 monitors (Individual), 100 monitors (Team) and 250 monitors (Agency).
Does Sentinel offer status pages or incident management?
Not on the Free plan — both are disabled at this tier. All of Sentinel’s paid plans (Individual, Team and Agency) include incident management, maintenance windows and public status pages as standard. Pingdom also includes one public status page per account and supports maintenance windows on its paid plans; formal incident management is not confirmed as a core built-in feature of Pingdom based on current public documentation.
How much do Sentinel’s paid plans cost?
Individual is £12/month (with a 7-day free trial), Team is £30/month, and Agency is £65/month. Annual pricing and discounts are not published on Sentinel’s pricing page.
How long does Sentinel retain historical monitoring data?
7 days on the Free plan, 30 days on Individual, 90 days on Team, and 365 days on Agency.