Site24x7 — the monitoring suite from the Zoho stable — has one of the few free tiers in this category that's generous where it counts: 1-minute check intervals, free, forever. That's faster than most rivals' paid plans, and 60× faster than our checks. If email alerts are enough for you, sign up there and this page won't talk you out of it.
The catch, again, is the alert channel. Per Site24x7's own plan-comparison table (September 2026), the free plan's alert channel is email — SMS arrives with the ~$9/month Uptime tier, and webhooks (with voice calls) appear on the Perf tier from ~$36/month. So the moment "email me" becomes "POST my webhook" or "ping the team channel", the free plan is over. That moment is what this page is for: one curl arms an uptime check whose alert is a webhook — Slack and Discord formats auto-detected, everything else HMAC-signed JSON — plus a public status page, README badge and Atom feed. No account anywhere in the loop. Small free capacity, honestly stated below.
Facts from Site24x7's own pages, September 2026 (both are JS-rendered, so quote-checking needs a real browser — verify current numbers yourself). Their free-website-monitoring page's comparison table lists the free plan as: 5 website monitors, 1-minute check frequency, 3 monitoring locations, HTTP(S) + ping test types, email alerts, 1 public status page. Their main pricing page banners the same plan as "monitor the uptime of up to 50 resources" with instant downtime email alerts — the two pages count differently (resources vs. website monitors), but they agree on the part that matters here: the free alert channel is email. The same table shows Uptime (from $9/month): 25 monitors, email + SMS; Perf (from $36/month): 40+ monitors, email/SMS/voice/webhooks, API + real-user monitoring types, 10 status pages.
Two things said plainly. First: their free 1-minute interval beats our 30-minute checks by a mile — if detection speed matters and email suffices, Site24x7's free plan is the better tool. Second: Site24x7's real product is breadth — APM, real-user monitoring, server/network/cloud infrastructure, logs, 130+ probe locations — none of which we have any equivalent for. This page is about one narrow moment: you want a webhook-alerting uptime check armed in ten seconds without a signup form.
curl -X POST https://mockbird.mockbird.workers.dev/api/status/monitor \
-H 'content-type: application/json' \
-d '{"url":"https://api.example.com/health","notify":"https://hooks.slack.com/services/T000/B000/XXXX"}'We GET your URL every 30 minutes from Cloudflare's network (8s timeout, redirects followed, 2xx/3xx = up). Your URL is probed immediately, so the response doubles as a one-shot "is my site up from outside?" check — and it contains everything else you need:
{
"id": "mon-XXXX",
"secret": "…",
"current": { "ok": true, "http_status": 200, "ms": 87 },
"checked_every_minutes": 30,
"status_page": "https://mockbird.mockbird.workers.dev/status/mon-XXXX",
"badge_svg": "https://mockbird.mockbird.workers.dev/status/mon-XXXX/badge.svg",
"feed_atom": "https://mockbird.mockbird.workers.dev/status/mon-XXXX/feed.xml"
}notify takes a Slack incoming webhook, a Discord webhook, or any HTTPS endpoint — the format is sniffed from the host: hooks.slack.com gets {"text": …}, discord.com/api/webhooks gets {"content": …}, and anything else gets JSON signed with your monitor's secret (x-mockbird-signature: sha256=hex(hmac-sha256(secret, body)) — verify it like a Stripe webhook). A confirmation delivery hits your webhook at create time so you know the channel works before you rely on it.
Alerting is deliberately quiet: one POST when the URL goes down, one when it recovers, debounced — two consecutive checks must agree, so a single blip never pages you. No retries, best-effort delivery, and 5 consecutive failed deliveries auto-remove the monitor (a dead webhook can't rot forever). No email, no SMS, no voice calls here, stated plainly — the webhook is the product.
Every monitor gets a public status page at an unguessable URL showing the hostname only, an SVG badge for the README, and an Atom feed of down/recovered events for anyone who'd rather poll than be POSTed at:
[](https://mockbird.mockbird.workers.dev/status/mon-XXXX)Polling a URL can't tell you the nightly backup didn't run — for scheduled work the job should ping the monitor. POST /api/status/heartbeat returns a secret ping URL; append && curl -fsS -m 10 <ping_url> to the cron job, and if pings stop arriving within period + grace you get one service.down webhook, one service.up on resume. Full recipes: cron-job monitoring with one curl.
| Site24x7 concept | Here |
|---|---|
| Website (uptime) monitor | POST /api/status/monitor {"url": …, "notify": …} — no account, response includes the current check |
| Email / SMS / voice alerts | notify webhook — Slack/Discord auto-detected, else HMAC-signed JSON. No email/SMS/voice, stated plainly |
| Webhook alerting (Perf tier, ~$36/mo there) | The default and only channel — free |
| Public status page (1 on their free plan) | One per monitor, unguessable URL, hostname-only — plus badge + Atom feed |
| 1-minute checks from 130+ locations | Honest: 30-minute checks from Cloudflare's edge as a single logical vantage point — they win this axis outright |
| DNS / port / API / RUM monitor types | No equivalent. We speak HTTP GET only |
| APM, server/network/cloud monitoring, logs | No equivalent. That breadth is Site24x7's genuine product |
| Cron/scheduled-work monitoring | POST /api/status/heartbeat — free dead-man's-switch, 30 min–7 day periods |
| API | The same URLs you created with; GET /api/status/monitor self-documents as JSON |
Facts checked September 2026 against each vendor's own pricing page — verify current numbers yourself:
| Free tier | Pick it when | |
|---|---|---|
| Site24x7 | 1-minute checks (fastest free interval we know of), email alerts, status page; SMS from ~$9/mo, webhooks from ~$36/mo | Email alerts are enough and you want fast detection, real dashboards — or you'll pay for the breadth (APM, RUM, servers, network, logs, 130+ locations). |
| UptimeRobot | 50 monitors, 5-min checks, dashboard; webhooks and heartbeats are paid (details) | You want a free dashboard watching many sites and email alerts are enough. |
| StatusCake | 3 monitors, 15-min checks, email to 1 address; integrations from $24.49/mo (details) | Email is enough and you want a dashboard without UptimeRobot's monitor sprawl. |
| Mockbird | URL monitors: 3 live per IP (deleting frees the slot), 30 total, 30-min checks. Heartbeats: 5 live per IP. Webhook + Slack + Discord alerts, status page/badge/feed — free, no account | The alert must be a webhook, and you want it armed this minute from a terminal, CI step, script or agent. |
Where Site24x7 wins, plainly: 1-minute free checks (60× faster than ours), multi-location probing, real dashboards, and — paid — the whole observability suite: APM, real-user monitoring, server/network/cloud infrastructure, logs, SMS and voice alerting, reporting, teams. We do: one curl, no signup, webhook down/up alerts with HMAC signatures, public status artifacts, and free heartbeats — at $0 where their webhook alerting starts around $36/month.
# info + 24h ok-rate + recent checks · then stop
curl "https://mockbird.mockbird.workers.dev/api/status/monitor/mon-XXXX?secret=YOUR_SECRET"
curl -X DELETE "https://mockbird.mockbird.workers.dev/api/status/monitor/mon-XXXX?secret=YOUR_SECRET"Both endpoints self-document on a bare GET. The complete walkthrough of the monitor feature is the uptime monitor API guide; we also run a public tracker of 50+ developer APIs at /status that you can subscribe alerts to without using a monitor slot.