Privacy Policy

Overview

This policy describes how DiffCheck.org handles information when you use the website. Most tools run entirely in your browser: the text, code, and files you paste for comparison are not uploaded to our servers. A few tools, named below, do contact a third-party service when you ask them to, and we use Google Analytics only if you agree to optional cookies.

The previous version of this page said cookies were not used for tracking or advertising. That is no longer accurate, and this update replaces it.

Last updated: 15 November 2026

What stays in your browser

For comparison and formatting tools, processing happens on your device with JavaScript. We do not receive the text, code, JSON, YAML, XML, CSV, files, passwords, tokens, or other content you paste into those tools, and we do not store it on a server.

Closing the tab discards what you pasted. You should still avoid pasting secrets if you would not be comfortable leaving them in this device's memory for a short time.

Analytics

If you accept optional cookies, we load Google Analytics (measurement ID G-MCC82ZJNWG) to understand how the site is used. Analytics may collect page URLs, approximate location (typically country or region), browser and device information, and online identifiers created by Google cookies. This is usage data, not the content of your diffs.

Analytics is off until you choose "Accept" on the cookie banner. If you choose essential cookies only, Google Analytics is not loaded. You can change this later on the Cookie Policy page.

Advertising

The site does not currently display ads or set advertising cookies. We may use Google AdSense in the future to show ads and support the site. If we do, advertising cookies will be treated as optional: they will not run unless you have accepted optional cookies, and this policy will be updated with the details then in use.

Cookies and local storage

Essential storage keeps your theme preference and your cookie choice in this browser (local storage, not a tracking cookie). The language version you are viewing is part of the page URL (/en/, /zh/, or /ja/).

Optional analytics cookies are set by Google only after you accept them. Cloudflare, which hosts and delivers the site, may also set cookies needed for security and delivery. The Cookie Policy explains each category and how to change your choice.

Third-party services

The site relies on the following services:

• Cloudflare Pages — hosts and delivers the website. Cloudflare may process technical data such as IP addresses in order to serve pages and protect the site.
• Google Analytics — optional usage statistics, only after you accept optional cookies. See Google's privacy policy.

A small number of tools send a request to a third party when you use them, because the lookup cannot be done in the browser alone:

• IP Lookup — queries ipapi.co with the IP address you enter, or with your public IP if you choose "My IP".
• DNS Lookup — queries Google's public DNS API (dns.google) for the domain you enter.
• SSL Checker — queries crt.sh for certificate records of the domain you enter.
• HTTP Header Inspector — fetches the URL you enter through a CORS proxy at api.allorigins.win.

Those requests include the address or URL you asked to look up, and they are not sent unless you run the tool. Some tool previews also load sample images from Unsplash. Each of these providers has its own privacy policy. We do not sell your information.

Browser extension

If you install the DiffCheck browser extension, it is intended to show the tool panel in the sidebar and to process content locally on your device. It should not be used as a reason to paste secrets that you would not paste on the website.

Changes

If this policy changes in a material way, we will update this page and the date above. The current version is always at https://diffcheck.org/en/privacy/.

Contact

Questions about privacy can be sent to hello@diffcheck.org or through the contact page.