Privacy

Information we collect

Broadly, three kinds:

• Information you give us. If you create an account, that includes the details needed to sign you in and any results you choose to save. Accounts are optional — no tool is gated behind one.
• Usage information. Aggregate signals such as which pages and tools are viewed, where visitors arrived from, and the feedback you send when you react to a tool. This is what tells us which tools are worth building on.
• Technical information.The ordinary details a web server receives with a request, including IP address, browser and device type. IP addresses are also used briefly to rate-limit our endpoints so they aren't abused.

Many tools on this site do their work locally in your browser, and some remember preferences or best scores on your own device rather than on our servers. Which tools work that way can differ from tool to tool, and may change as new ones are added.

How we use it

To operate and secure the site, to keep your account and saved results working, to understand which tools people find useful, and to decide what to build next.

We don't sell your personal information, and we don't try to work out who you are as a person. What we actually look at are counts, totals and patterns describing visitors as a group rather than anybody in particular, and information in that form is what we use to improve the tools, decide what to build next, and report on how the site is doing. One of the analytics services does keep a per-browser record underneath those totals, which is described in the cookies section below — it is tied to a browser, never to your name or email, and we don't use it to look anyone up individually.

Advertising is the one place where a third party — Google — may use information about your browsing to decide which ads you see. That's described in full below, along with how to turn it off.

Advertising

100jacks is free to use and is supported by advertising. Ads on this site are served by Google, and in some cases by other third-party vendors.

• Third-party vendors, including Google, use cookies to serve ads based on your prior visits to this website or to other websites.
• Google's use of advertising cookies enables it and its partners to serve ads to you based on your visit to this site and/or other sites on the internet.
• You can opt out of personalised advertising by visiting Google's Ads Settings.
• To opt out of personalised advertising from many other vendors at once, visit www.aboutads.info.

Opting out of personalised ads doesn't remove ads from the site — it means the ones you see aren't chosen based on your browsing.

Cookies and analytics

One analytics service sets a cookie in your browser. The others store nothing on your device at all — not a cookie, and not the quieter equivalents, because local storage is the same thing in every way that counts.

Analytics. We use a small number of analytics services to understand how the site is used: which pages and tools get viewed, where visitors arrived from — search results, links, and increasingly AI assistants — and coarse technical details such as country, language, browser and device type. Most of them measure only in aggregate and keep no identifier on your device, so a visit is counted today without you being recognisable tomorrow.

The exception is a general web analytics service, and it is worth being direct about it. It uses that cookie to recognise the same browser across visits, which is what lets us count how many separate people visited rather than only how many times a page loaded, and see which countries they came from. That record is tied to a browser rather than to your name or email. It is not combined with any account you may have here, and it is not sold or shared for advertising. It does not record your screen and it does not capture what you type into a tool — the figures you enter and the notes you save stay in your browser or in your own account, as described above. What it keeps is which pages you opened, and when.

Blocking cookies in your browser, or using any of the tracker-blocking extensions, stops that service from recognising you, and the site works exactly as before — nothing here depends on it. Bot traffic is excluded from all of these numbers.

This site also keeps its own count, separately from those services. When you open a tool, it adds one to two numbers: how many times that tool was opened today, and how many times it was actually used. That is the whole record — a date, the tool's name, and a total. There is no row for you in it, and nothing in it could be traced back to you even in principle, because nothing about you is written down. It counts visits, not people, which is why you will not find a visitor count here that claims otherwise.

Advertising.Advertising cookies go further than the analytics one. As described in the previous section, Google and other vendors may set cookies in your browser to choose and measure ads, and those cookies can relate to sites other than this one. The opt-out links above are the direct way to switch that off, and your browser's own cookie controls work here as they do anywhere else.

Cookies that are strictly necessary — for example, to keep you signed in if you have an account — may also be used.

Service providers

We rely on a small number of third parties to run the site: to host and deliver it, to provide the aggregate measurement described above, to keep the view and reaction counters, to serve the advertising described above, and to handle sign-in for people who create an account. They process information on our behalf and under their own privacy terms, and only for those purposes. We may add or change providers over time, and this page is updated in the same release when we do.

Data stored on your device

Where a tool saves something locally, it uses your browser's localStorage, which is not encrypted. On a shared or public computer, whatever it holds stays there for the next person to open the same browser, until it's cleared. Don't use a tool here to hold anything you'd call confidential. See the terms page for the same point put plainly. Clearing your browser data removes it.

Keeping it safe, and how long we keep it

Information is held with the ordinary protections you would expect — encrypted in transit, access limited to what running the site requires. No service can promise perfect security, and we don't.

We keep what we hold for as long as it is useful for the purposes described above, and no longer than we need it. If you have an account, anything saved to it stays until you delete it or close the account. You can ask us to delete what we hold at any time, using the address at the bottom of this page.

Children

This site isn't directed at children, and we don't knowingly collect personal information from them. If you believe a child has given us information, write to us at the address below and it will be removed.

Your choices

You can use the tools without signing in, opt out of personalised advertising through the links above, clear anything a tool has stored locally through your browser's settings, and delete your account if you created one. Browser-level controls such as blocking scripts or cookies work here as they do anywhere else. If you want to know what we hold about you, or want it deleted, ask us at [email protected].

Changes to this policy

As the site develops we may collect more, less, or different information than we do today — a new feature might need a server where an older one didn't. When that happens, this page is updated in the same release that makes the change, not afterwards.

Getting in touch

Questions about any of this, or a request about your own information, go to [email protected]. There's more on the contact page.