Privacy policy.

This policy describes how IP CIDR Calculator (ipcidrcalculator.com) handles information. It applies to this website and nothing else. It took effect on 25 August 2026.

What the site collects

Nothing. There is no account system, no sign-up, no contact form, no comment section, no newsletter and no advertising. The site sets no cookies and runs no analytics, tag manager, session recorder, heat-map or fingerprinting script of any kind.

There is also no server-side code to collect anything with. The site is compiled into static HTML, CSS and JavaScript files and served as-is; there is no application server, no database and no API endpoint behind it.

The addresses you type into the calculator

Every calculation — splitting a block, converting a mask, expanding a range — is performed by JavaScript running inside your own browser. IP addresses, prefixes and ranges you enter are not sent to this site, not written to any server, and not stored anywhere after you close or reload the page.

This is worth stating plainly because internal addressing plans are sensitive. You can confirm it: open your browser's developer tools, switch to the network panel, and use the calculator. After the page and its fonts have loaded, no further requests are made. You can also disconnect from the network entirely and every tool will keep working.

What is stored on your device

One item, and only if you ask for it. Choosing the light theme writes a theme key to your browser's localStorage so the choice survives a reload. It contains the single word light, it is readable only by this site, it is never transmitted, and switching back to the dark theme deletes it. Clearing site data in your browser removes it too.

No cookies are set, which is why the site shows no cookie banner. There is no consent to collect, because there is nothing to consent to.

Fonts and other assets

The typefaces are downloaded when the site is built and served from this domain alongside everything else, so displaying a page makes no request to Google Fonts or to any other font host. Images, icons and scripts are likewise served from this domain only. No content is embedded from a third-party network.

Server logs

The static files are delivered by a hosting provider. Like effectively every web host, that provider may record standard request information — the IP address the request came from, the time, the file requested, the user agent — for the purpose of serving traffic, diagnosing faults and mitigating abuse. Those logs are created and controlled by the provider under its own policy, are not used to build any profile, and are not analysed, exported or combined with anything else. Nothing you type into a calculator ever appears in them, because it is never sent.

If you send an email

Writing to hello@ipcidrcalculator.com means your address and message arrive in a mailbox, as with any email. It is used to answer you and for nothing else: it is never added to a mailing list, never sold, and never shared with a third party. Correspondence is deleted once the matter is closed, other than where a record is needed for a legal or security reason.

Children

The site is a technical reference tool and is not directed at children. Since it collects no personal information from anyone, it collects none from children either.

Your rights

Data protection law — including the GDPR and the CCPA — gives you rights of access, correction, deletion, portability and objection over personal data held about you. Those rights are honoured here in the simplest possible way: no personal data about visitors is held, so there is nothing to access, correct, export or erase, and nothing that could be sold or shared. No personal information is sold or shared for cross-context behavioural advertising, and none ever has been.

If you have written in, you can ask at any time for that correspondence to be deleted, and it will be.

Links to other sites

The site links out to specifications and reference material, such as the RFC Editor. Those sites have their own privacy practices, and this policy does not cover them.

Changes to this policy

If this policy changes, the revised version will be published here with a new effective date at the top of the page. Because the site collects nothing, changes are expected to be rare and clarifying rather than substantive. Continued use of the site after a change means you accept the revised policy.

Contact

Privacy questions can be sent to hello@ipcidrcalculator.com, or via the contact page. The operator of this site for the purposes of this policy is IP CIDR Calculator (ipcidrcalculator.com).