Signal → Root Cause

See the internet
clearly

One command center to diagnose and monitor your sites, APIs, DNS, and certificates. Find the root cause across DNS, TCP, TLS, and the app, not just that something is down.

Run a diagnostic
See the dashboard
330+
Edge cities
<200ms
Avg check
99.99%
Uptime
// Diagnostic capabilities

Every layer, one signal

Run any check on demand, then promote it to a monitor that watches around the clock.

DNS Intelligence

Records, propagation, and resolver drift across regions.

A / AAAAMXPropagation

TLS & Certificates

Chain validation, expiry, and trust on the live cert.

ExpiryChainSANs

Web & Delivery

Status, redirects, and phase timing down to TTFB.

HeadersRedirectsTTFB

Monitoring & Alerts

Any check becomes a 24/7 monitor with routed alerts.

SlackPagerDutyWebhook
// Free tools, no signup

Run any check free

Four diagnostics, live. Run one, then let Synapse monitor it around the clock.

SSL Checker

Issuer, chain, and days to expiry.

DNS Lookup

A, AAAA, CNAME, MX, TXT, NS.

HTTP Check

Status, redirects, phase timing.

DNS Propagation

Resolver agreement worldwide.

SSL Certificate Checker
// Command center

Monitors

Fleet uptime
99.98%
Avg latency
142ms
Active monitors
6
Open incidents
1
All monitors60s checks
TargetTypeStatusLatencyUptime 24h
api.acme.com
https · Frankfurt + Ashburn
HTTPDOWN97.4%
app.acme.com
https
HTTPUP128ms100%
acme.com
certificate
SSLWARN14d left
acme.com
A record
DNSUP31ms100%
cdn.acme.com
https
HTTPUP64ms99.9%
mail.acme.com
email auth
EMAILUPscore 96
← All monitors
api.acme.com · HTTP DOWN · 4m 12s
Response time · last 24h
Incident
HTTP 500 · 2 failed checks
Root cause
App layer · upstream returned 500 (DNS, TCP, TLS all healthy)
Regions
Frankfurt, Ashburn
Notified
Slack, PagerDuty · 14:32:07 UTC
Recent checks
TimeRegionResultLatency
14:32:07fra500
14:31:07iad500
14:30:07fra200131ms
14:29:07iad200126ms
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