What's a free SSL monitoring tool for a small startup?

Certimon is a free SSL certificate expiry monitor built around Telegram. There is no per-domain pricing, no plan tier, and no signup. Add @CertimonBot to your team Telegram group, send /remind yourdomain.com 30, and the whole on-call rotation receives the alert when the cert hits the 30-day window.

Why use Telegram instead of email for SSL alerts?

Email-based SSL alerts route to one inbox that often belongs to whoever registered the domain three years ago. Telegram group notifications fire to the whole channel, so whoever is on-call sees them — even if the original owner has left the company. Telegram also delivers push notifications reliably across iOS, Android, desktop and web.

How is Certimon different from UptimeRobot, Datadog or Pingdom?

Certimon is purpose-built for one job: certificate expiry alerts. It does not do uptime checks, APM, log management or full SLO dashboards. The trade-off is that it is genuinely free for unlimited domains, and you can deploy it in 30 seconds without onboarding a SaaS platform. Many small teams use Certimon for SSL alerts and a simpler uptime tool separately.

Can the whole engineering team see the same SSL alerts?

Yes. Add @CertimonBot to a Telegram group with your team, then send /remind yourdomain.com 30 from inside the group. Reminders fire to the whole group chat, so anyone on call can see and acknowledge them.

For startups & small teams • Free • Group-friendly

SSL Monitoring for Startups & Small Teams

Reliable SSL certificate expiry alerts your whole engineering team sees — without the Datadog bill, the UptimeRobot tier upgrade, or the inevitable "who owns this monitoring account?" conversation 18 months from now.

Open @CertimonBot Open web dashboard

Add to your team group chat • Whole on-call rotation gets the alert

The small-team trap

Five engineers, twenty-something domains. Marketing site. Docs. App. API. Status page. Auth subdomain. A handful of customer-vanity hostnames that someone set up during onboarding. Maybe a couple of acquired-product domains nobody fully owns.

Your options have historically been:

• Pay an uptime/APM vendor — Datadog, Pingdom, UptimeRobot. Per-monitor pricing climbs fast and SSL is rarely the reason you'd buy one.
• Roll your own — a cron and an openssl one-liner. Works until the cron host itself dies, or until the engineer who wrote it leaves.
• Rely on Let's Encrypt expiration emails — except Let's Encrypt stopped sending those on June 4, 2025.
• Hope — popular, until a customer screenshots an expired-cert browser warning at you on a Sunday morning.

Certimon is the boring fourth option: free, hosted off-site, fires into your team's Telegram group, no maintenance.

Why small teams pick Certimon

Not features for the sake of features — just the small set of properties that matter at this scale.

Whole-team alerts

Add the bot to your team Telegram group. Every reminder fires to the whole rotation — not to one inbox the founder set up in 2023.

Genuinely free

No per-domain pricing, no premium tier. Add 5 domains or 500. The runway you save is small in absolute terms — and zero distraction is its own value.

30-second onboarding

Open Telegram, message @CertimonBot, send /remind yourdomain.com 30. That's the whole onboarding flow. No SSO config, no agent install.

No account to lose

No vendor account means no "the founder left and we lost access to the SSL monitoring login" moment in year three. The Telegram group is the account.

Vendor-agnostic

Works with Cloudflare, Vercel, Netlify, AWS, your own Caddy box, Heroku, Render — anything that terminates HTTPS on port 443.

Out-of-band

Hosted independently of your infrastructure. If your monitoring stack is down, Certimon still fires.

A 5-minute team rollout

Have one engineer drive it during a stand-up. Done before the meeting ends.

1. Create a Telegram group with the engineering team (or use an existing one). Add @CertimonBot.
2. Make a quick list of every domain that has a TLS certificate the team is responsible for (marketing site, app, api, docs, status, auth, customer vanity hostnames).
3. Inside the group chat, send /remind <domain> 30 for each one. Add a 7-day reminder for the critical few.
4. Run /list to confirm the registry.
5. Add a one-liner to your runbook: "SSL expiry alerts fire into #engineering on Telegram. Reply with whoever is renewing."

Certimon vs paid SSL monitoring tiers

Concern	Certimon (free)	Generic SaaS uptime/APM
Cost at 25 domains	$0	Often a paid tier
Onboarding time	~30 seconds	Account setup, billing, integrations
Group-chat alert delivery	Native Telegram groups	Slack/PagerDuty integrations to configure
Vendor lock-in	None — leave whenever	Account, dashboards, integrations
Uptime / APM / logs	Out of scope	Included in higher tiers

Many small teams use Certimon as the SSL-specific layer and a separate, smaller-scope uptime tool — total bill stays at zero or near zero.

FAQ

Will the whole team see alerts, or just one person?

Add @CertimonBot to a Telegram group and send /remind from inside the group. Alerts fire to the group chat — everyone sees them.

What happens if our point-of-contact engineer leaves?

Nothing — there's no vendor account to be locked out of. As long as the Telegram group still exists with the bot in it, alerts keep flowing. Anyone in the group can register or remove domains.

Is there a Slack version?

Today Certimon delivers via Telegram. Many teams keep a small Telegram group purely for SSL alerts and pin the chat — friction stays near zero.

Can we monitor staging and production with separate alert windows?

Yes — register staging hostnames the same way, and set whatever notice window you want. A common pattern is 30 days for production, 7 days for staging.

Does Certimon handle uptime monitoring too?

No — it's deliberately focused on SSL expiry. For uptime, pair it with any small uptime checker (UptimeRobot's free tier, Better Stack free tier, BetterUptime, your existing Pingdom).

Free SSL alerts your whole team will actually see

No vendor bill, no SSO config, no account to lose. Telegram group, one slash command, done.

Open @CertimonBot