Compute network details of a CIDR block — network & broadcast address, usable ho
Compute network details of a CIDR block — network & broadcast address, usable host range, total and usable address counts. Works for IPv4 and IPv6 (counts returned as strings for large IPv6 blocks). Honours RFC 3021 for /31.
Answeringour last check, 2026-09-24
1 of 1checks answered this week
458 msmedian answer time
$0.002listed price per call
$0.002price it asked us
Paid test badge: not yet. The checks above are free: we call the tool without paying and read the payment request it sends back. The Verified badge needs paid calls whose answers match the promised output, and nobody can buy a badge.
Endpoint
POST https://ip.openverbs.com/v1/subnet
| Category | Everything else |
|---|---|
| Provider host | ip.openverbs.com |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 3 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-09-24 | valid payment request | 402 | $0.002 | 458 ms |
Example input (from the provider)
{
"body": {
"cidr": "example"
},
"bodyType": "json",
"method": "POST",
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"body": {
"additionalProperties": false,
"properties": {
"cidr": {
"description": "CIDR block, e.g. \"192.168.1.0/24\" or \"2001:db8::/48\".",
"maxLength": 64,
"minLength": 3,
"type": "string"
}
},
"required": [
"cidr"
],
"type": "object"
},
"bodyType": {
"enum": [
"json",
"form-data",
"text"
],
"type": "string"
},
"method": {
"enum": [
"POST"
],
"type": "string"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method",
"bodyType",
"body"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}