Turn a start and end IPv4 or IPv6 address into the smallest list of CIDR blocks
Turn a start and end IPv4 or IPv6 address into the smallest list of CIDR blocks that covers exactly that range (at most 62 for IPv4, 254 for IPv6). Offline. Use when an agent must write a range from a provider or registry as firewall, ACL or SPF entries. Input: ?start=192.0.2.10&end=192.0.2.20.
Answeringour last check, 2026-10-31
2 of 2checks answered this week
364 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
GET https://api.lookproof.dev/v1/ip/range-to-cidr
| Category | Company and compliance |
|---|---|
| Provider host | api.lookproof.dev |
| Networks | eip155:8453 |
| Payment schemes | exact |
| Self-reported calls, 30 days | 1 from 1 payers (the provider's figure, not ours) |
Our checks, last 30 days
| Day | Result | HTTP | Asked | Time |
|---|---|---|---|---|
| 2026-10-31 | valid payment request | 402 | $0.002 | 347 ms |
| 2026-10-29 | valid payment request | 402 | $0.002 | 382 ms |
Example input (from the provider)
{
"method": "GET",
"queryParams": {
"end": "192.0.2.20",
"start": "192.0.2.10"
},
"type": "http"
}
Promised output schema (from the provider)
{
"$schema": "https://json-schema.org/draft/2020-12/schema",
"properties": {
"input": {
"additionalProperties": false,
"properties": {
"method": {
"enum": [
"GET",
"HEAD",
"DELETE"
],
"type": "string"
},
"queryParams": {
"additionalProperties": false,
"properties": {
"end": {
"maxLength": 64,
"minLength": 2,
"title": "End",
"type": "string"
},
"start": {
"maxLength": 64,
"minLength": 2,
"title": "Start",
"type": "string"
}
},
"required": [
"start",
"end"
],
"title": "IpRangeInput",
"type": "object"
},
"type": {
"const": "http",
"type": "string"
}
},
"required": [
"type",
"method"
],
"type": "object"
}
},
"required": [
"input"
],
"type": "object"
}