Limits and defaults

Workspace

Limit	Value
Monitors per workspace	20
Members per workspace	no limit
Alert channels per workspace	no limit
Channels per monitor	no limit

Timing

Setting	Range	Default
Check interval	20 seconds – 24 hours	60 seconds (probed types)
Check interval	20 seconds – 24 hours	24 hours (certificate, domain, DNS, email auth)
Timeout	1 – 60 seconds	10 seconds
Failures before down	1 – 10	2
Re-alert interval	5 minutes – 24 hours, or off	off

HTTP monitors

Setting	Range	Default
URL length	up to 2048 characters	—
Accepted status	codes and inclusive ranges, e.g. `200-299,301`	`200`
Max redirects	0 – 10	0
Keyword length	up to 200 characters	none
Response body read for keyword match	up to 256 KB	—
Second opinion	on / off	on

TCP monitors

Setting	Range
Port	1 – 65535

Heartbeat monitors

Setting	Range	Default
Expected ping interval	1 minute – 7 days	1 hour
Grace period	0 seconds and up	5 minutes
Ping token length	up to 128 characters	—

Certificate and domain monitors

Setting	Range	Default
Warning threshold	1 – 365 days	30 days

DNS monitors

Setting	Values	Default
Record type	A, AAAA, MX, TXT, CNAME, NS	A
Expected value	any substring, optional	none

ICMP monitors

Setting	Range	Default
Echo requests per check	1 – 10	4
Packet-loss threshold	0 – 99 %	0 %

UDP monitors

Setting	Values	Default
Payload	dns, ntp, stun, raw	dns
Raw payload / expected reply	hex, up to 256 bytes	—

gRPC monitors

Setting	Values	Default
Service name	blank asks about the server as a whole	blank
TLS	on / off	off

API

Limit	Value
Read requests	600 per minute, per key
Write requests	60 per minute, per key
Page size	1 – 100, default 25
Idempotency-Key replay window	24 hours

SMTP and IMAP monitors

Limit	Value
Port	1 – 65535
STARTTLS	on or off; on by default
Timeout	1 – 60 s, default 10 s
Greeting recorded	first token only

Implicit-TLS ports — 465 and 993 — are not supported; the handshake precedes the greeting. Use a TCP monitor there.

Data

Item	Value
Raw check result retention	7 days
Uptime windows available	last 24 hours, last 7 days
Long-term aggregation	none
Incident retention	until the monitor is deleted
Monitor name length	up to 80 characters
Stored error message length	up to 200 characters

Targets

Rule	Applies to
`http` and `https` schemes only	HTTP monitors
URLs with embedded credentials rejected	HTTP monitors
Private-network targets refused by default	HTTP and TCP monitors
Bare domain required — no scheme, port, path or IP literal	certificate, domain, DNS, email auth

“Private-network” covers loopback, RFC1918, link-local (including the cloud metadata address), CGNAT, IETF protocol assignments, benchmarking and multicast ranges, plus the IPv6 equivalents and internal-only hostname suffixes. Detail: security model.

Not limits — things that do not exist

So you do not go looking for the setting:

No probe location selection. Checks run from one location.
No status pages, maintenance windows, incident acknowledgement, tags or on-call scheduling. See the roadmap.
No SMS or phone alerts.
No generic “UDP port open” check — see UDP monitors for why that question cannot be answered.