Privacy Policy

Network calculations

IPv4 and IPv6 calculations run in your browser. The application does not send your entered CIDR blocks, network addresses or generated plans to its analytics service. Inputs and results remain in page memory. Copy and CSV export happen only when you request them.

The site is hosted by Cloudflare, Inc. using Cloudflare Pages. Delivering and protecting the site involves processing connection information such as your public IP address and HTTP request information. The purpose is to provide a functioning, secure service, on the basis of the controller’s legitimate interests under Article 6(1)(f) GDPR.

The publisher does not collect or retain Cloudflare request logs for this service. Cloudflare processes connection data to deliver and protect the site; its own processing is described in Cloudflare’s Privacy Policy. Do not enter secrets or personal data into network fields.

Cloudflare makes infrastructure request and performance metrics available in its dashboard. Its privacy policy determines retention according to the processing purpose, necessity and legal obligations. For data processed on the publisher’s behalf, its published DPA uses the earlier of contract termination or the point when processing is no longer necessary for contractual obligations, subject to its legal exceptions.

Separate Cloudflare performance measurements

Cloudflare Web Analytics is configured to load its performance script automatically for visitors outside the EU. This separate service measures visits and page performance and operates independently of this application’s PostHog consent controls. Cloudflare describes its performance beacon and reporting endpoints in its documentation.

Optional PostHog statistics

“Accept statistics” enables PostHog to measure page visits, successful and failed split attempts, exports, copies and planner mode changes. Properties are restricted to IP version, prefix lengths, subnet or exported-row counts, calculation duration, a fixed error category, export format, a recognized page path and SDK-generated pseudonymous identifiers and metadata.

“Continue without cookies” declines analytics cookies and enables only PostHog page-view measurement. No calculator actions are sent in this mode. PostHog receives a recognised page URL, its hostname, browser user-agent information, event time and library metadata. It also processes the connection IP address to calculate a daily identifier on its servers. The browser sends a common cookieless marker instead of a visitor, device or session identifier. No analytics identity is saved in cookies, localStorage or sessionStorage.

PostHog describes its cookieless processing as hashing the project, daily salt, IP address, user agent and hostname, then removing the IP and user agent from the event. This is still processing of connection and browser data. The daily identifier cannot measure returning people across days: one person may count again each day, and people sharing an IP and browser configuration may be combined. Counts are estimates, not verified unique people.

Both statistics modes are optional and based on your choice under Article 6(1)(a) GDPR. No PostHog request is sent before you choose a mode. “Refuse statistics” disables both modes; existing recorded refusals remain refusals. Every calculator remains available. Session recordings, automatic click capture, surveys, heatmaps, automatic error capture and feature-flag requests are disabled. Search strings, URL fragments, referrers, typed addresses and error text are excluded. Geolocation and person profiles are disabled.

The statistics service is PostHog, Inc., using PostHog Cloud European Union and the EU ingestion endpoint. PostHog receives connection information when statistics are enabled, including the public IP address needed to transmit requests. The controller uses the resulting statistics to understand tool usage and errors.

The current PostHog Free plan provides a one-year window for analysing events, as described in PostHog’s event-retention documentation. This query window does not guarantee physical erasure of all underlying data or backups at that date. The six-month browser consent preference does not set the retention period of events already sent to PostHog. Contact [email protected] for requests concerning those events.

Your choice and browser storage

The consent preference is stored for six months to apply and remember your detailed, cookieless or refused choice. This preference is necessary to respect your decision and the controller’s related legal obligations. Use Cookie preferences to change your mode or select “Refuse statistics” at any time. Refusal stops future capture in both modes, aborts pending browser requests and clears accessible PostHog browser storage. It does not automatically erase events already sent; contact [email protected] to request access or deletion.

See the Cookie Policy for storage details. When browser storage is blocked, your choice is kept only for the current page session. Do Not Track and Global Privacy Control disable both PostHog modes.

Contact emails

If you email the controller, your email address, message and any information you choose to send are used to respond. Ordinary enquiries are handled on the basis of the controller’s legitimate interest in responding; privacy-rights requests are handled to meet GDPR obligations. Correspondence is received through Google’s Gmail service. See Google’s Privacy Policy.

Correspondence is reviewed and deleted from the mailbox no later than 12 months after the enquiry or request is closed, unless a legal obligation or an actual dispute requires longer retention. In that case, only information necessary for that purpose is retained for the applicable period. Google describes its general deletion process as usually taking around two months, with encrypted backup copies potentially retained for up to six months and exceptions for legal or security purposes. These provider-side periods are separate from the controller’s 12-month mailbox rule. See Google’s retention policy. Do not send passwords, identity documents or network plans unless they are specifically necessary for your request.

Providers and international processing

The controller and the services needed for hosting, optional statistics and email correspondence receive the information described above. Cloudflare operates a global network. Choosing PostHog’s EU region does not, by itself, establish the location of every support operation or subprocessor.

Section 6.1 of Cloudflare’s published Self-Serve Subscription Agreement incorporates its Data Processing Addendum for covered personal data. The DPA provides for standard contractual clauses for restricted transfers and addresses the Data Privacy Framework. Cloudflare also describes its own network-data processing in its Privacy Policy.

PostHog describes its international processing and subprocessors in its Privacy Policy and subprocessor list. The EU hosting region does not guarantee that every support operation or subprocessor is located in the EEA.

For personal Gmail correspondence, Google publishes international-transfer frameworks, including adequacy decisions, the EU–US Data Privacy Framework and standard contractual clauses where applicable.

Provider information and available safeguards can be requested from [email protected].

Your rights and contacts

Under the GDPR and subject to its conditions, you may request access, rectification, erasure or restriction of processing. Data portability applies where its conditions are met. You may object to processing based on legitimate interests and withdraw statistics consent at any time without affecting the lawfulness of earlier processing. This application does not make automated decisions producing legal or similarly significant effects.

Send your request to [email protected], describing the right you wish to exercise. There is no need to send an identity document by default. Additional verification may be requested if there are reasonable doubts about your identity. Requests are handled without undue delay and normally within one month; complex or numerous requests may require up to two additional months, with the reason communicated within the first month.

Analytics identifiers are pseudonymous and are not linked to an account or an email address by this application. If the available information does not allow the controller to locate your data, you will be informed; the controller will not ask for unrelated information merely to identify an anonymous visit.

You may lodge a complaint with the French supervisory authority, the Commission nationale de l’informatique et des libertés (CNIL), or another competent supervisory authority.