Privacy policy / nothing leaves the board
Last updated: October 2026
APISimul ("we", "us") is responsible for apisimul.com. This page describes the data we handle and the control you have over it. The summary: the mock rules, status codes and response bodies you define never leave your device, because that is where the calculation runs.
The tool this policy covers
APISimul does one thing — as a browser-based API mock simulator it intercepts fetch and XHR calls with a service worker so you can test a front end against fake endpoints without running a backend. The service worker registers a request handler that matches your rules by method and URL pattern, then returns the status code, latency and JSON body you configured before the request ever reaches the network. What follows concerns only that tool and the inputs involved in it.
In day-to-day use the tool works only from the mock rules, status codes and response bodies you define, and it is usually opened for things like building a UI before the real API exists. None of that reaches us, so none of it can be stored.
Data you give the tool
This site has no backend that receives what you type. The page reads your input to compute an answer, shows it to you, and forgets it — because nothing was ever sent anywhere in the first place. The arithmetic is identical regardless of who is looking at the screen.
Your rights
Wherever you are, you can ask what we hold about you, ask for it to be corrected or erased, and object to how it is used. Given how little APISimul collects, the answer will usually be short, but the right stands.
How this policy changes
This policy is reviewed when the site changes. Any material revision is shown by the "last updated" date at the top of the page.
Information collected as you browse
Like most websites, our hosting and analytics providers may process the basic technical information needed to deliver a page: IP address, browser and device type, referring page and pages viewed. This is used for security, troubleshooting and understanding which tools are used, and is never joined to anything you type into the tool.
Advertising, cookies and your choices
Advertising keeps the site free and is delivered by external networks, which may use cookies or similar technologies to show interest-based ads. Google, as one such partner, lets you opt out through its ad settings. Turning cookies off does not break anything here.
Analytics and aggregate statistics
Usage statistics, when collected, are anonymous and aggregated. They tell us which pages are useful; they do not identify you and they never include your input to the calculator.
What you paste is not uploaded
Code, configuration, tokens and API payloads you paste into a tool are processed locally. Nothing is uploaded, so nothing leaves a copy on a server — which also means you can use the tool on a string you would not want to send anywhere.
Security and data retention
No personal calculation data is held by us at any point, which makes retention a non-issue for the tool. The site itself is delivered over encrypted connections and kept up to date.
Under-13 users
Nothing here targets users under 13. If a child has sent personal details through the site, tell us and we will delete them.
Questions about this policy
Questions about this policy can be sent through the contact page.