toolsko

Choose your language

ToolsKo is written in English. Prefer another language? Open a translated version of this public page.

Browser language suggestion: English. You can choose any language below.

Translation opens in a new tab using Google Translate. It receives this public page URL. Automatic translations may contain mistakes; use the original English page for tool inputs, downloads, and generated documents.

Your choice is remembered on this browser when storage is available. Use Language in the header to change it.

IP Range to CIDR Converter

Convert a start–end IP range into the smallest list of CIDR blocks (and back).

Tool inputs stay in your browser · optional AI search sends your query

Good to know: Firewalls and cloud settings often need CIDR blocks instead of ranges. One range per line: “10.0.0.0 - 10.0.3.255” or a CIDR like “10.0.0.0/22”.

How to use it (step by step)

  1. 1Type or paste your text into the “Ranges or CIDRs (one per line)” box. There is already an example in it so you can see how it works; press Clear to start with your own.
  2. 2The answer appears right away in the “Result” box. No button needed.
  3. 3Press Copy and paste the result wherever you need it.

Words to know

Unit conversion
Changing a value from one measurement to another, like kilometers to miles. The amount stays the same; only the unit changes.
Page range
A way to choose pages: 1-3 means pages 1 to 3; 5 means only page 5; 7- means page 7 to the end.
IP address
The address of a device on the internet, like a house number for your connection. Websites need it to send pages back to you.
Subnet / CIDR
A way to split networks into blocks. 192.168.1.0/24 means 256 addresses from 192.168.1.0 to 192.168.1.255.
Array / list
An ordered collection of items, like ["apple", "banana"]. Every programming language has one.

More in Network & Internet

IP Address Lookup (Owner & Location)Find who owns any IP address or website, its country, range, hostname and abuse contact.DNS Lookup (A, MX, TXT, CNAME…)Check any domain’s DNS records and compare Cloudflare vs Google to see if changes have spread.Email Setup Checker (MX, SPF, DKIM, DMARC)Check if a domain is set up to receive email and protect against fake senders.Domain WHOIS Lookup (RDAP)See a domain’s registrar, registration and expiry dates, status and name servers.Internet Speed TestMeasure your download, upload, ping and jitter in about 20 seconds.WebRTC Leak Test (VPN Check)Check if your browser reveals your real IP through WebRTC while using a VPN.