Privacy Policy

Who we are

Binary Decimal (“we”, “us”) runs binarydecimal.com. You can reach us through the contact form.

What you type into the tools

Calculators, converters and editors do their work in your browser. The numbers and text you enter aren’t sent to us.

Many tools keep their inputs in the page address, so a result can be bookmarked or shared as a link. Anyone you send a link to can see what’s in it. Our host receives the full address when a page loads (see Hosting), and when a shared result from the penis size or GLP-1 calculator is opened, it reads the values in the link to draw the preview card that chat apps show. The address Google Analytics receives never includes them.

On-device AI helpers. In browsers with built-in AI, such as desktop Chrome, the Markdown editor can summarise, rewrite, proofread, translate or draft text, and the Mermaid editor can draw, explain or fix a diagram, using the browser’s own on-device model. It runs on your computer and your text never leaves this device. The first time, your browser downloads the model from its maker (Google, for Chrome), as it does for any site that uses it.

Ask in your own words. Some calculators let you type a question (“$450k house, 10% down”). Your browser reads it without any AI and shows what it understood before changing anything; only when it can’t, and your browser has built-in AI or you’ve added your own key, does an AI model read it. The question isn’t saved or put in the page’s address.

AI features with your own key

This is off unless you turn it on. In Settings → AI or on the AI tools page you can add your own key for OpenRouter, OpenAI, Anthropic or Google’s Gemini API, and the AI features (the Markdown and Mermaid editors, blood sugar insights, the AI tools) then use that provider instead of the built-in AI, as does a calculator’s Ask when it needs AI.

• Where your text goes. When you use an AI feature, what you ask it to work on (the selected text, a diagram’s code, the blood sugar insights’ facts and your question, never your readings, or a calculator’s Ask question and, for “Explain my result”, the result’s figures) goes from your browser straight to that provider, under its own terms and privacy policy. With OpenRouter, it also goes to the maker of the model you picked. It never goes through our servers, and we never see it or the answer. The AI panel says where it’s sent each time, and explains it the first time you use a provider. Tools that send a whole document show you the exact text, and what it could cost, before you send it.
• Your key. It’s kept in your browser: for the current tab only unless you choose “Remember on this device”. It’s never synced, included in a backup, put in a link, sent to analytics or sent to us; it’s sent only to the provider it belongs to. “Remove key” deletes it. “Sign in with OpenRouter” creates a key on OpenRouter’s site and hands it to your browser directly.
• Your key and usage stats. Any script running on this site can technically read what the site stores in your browser, including a key, whether it’s kept for the current tab or remembered. Google Analytics is the only third-party script we load, apart from the page-speed script our host adds (see Page speed). The risk is extremely small, but not zero. We never send Google Analytics your key, your prompts or the answers. Adding a key doesn’t change your usage stats choice: while a key is stored and stats are on, Settings → AI says so, with a button to turn them off. You can also turn them off any time in Settings → Advanced privacy, after which Google Analytics doesn’t load at all on this device. Removing the key doesn’t change that choice either.
• Private mode. With OpenRouter, private mode is on unless you turn it off: your text is only sent to providers that keep nothing after answering (zero data retention) and don’t collect it for training. Free models can’t offer that; their providers may log prompts, and the page says so before you use one.
• Costs. Calls are billed by the provider to your key, so give it a spending limit. Before a call that could cost more than $0.05, you see the exact text and the most it can cost, and once the tab has spent $0.50 calls stop; you can change both in Settings. After each call the panel shows what it cost (OpenRouter reports it; for the other providers it’s worked out from their list prices). Calls are never retried automatically.

What the tools save on your device

Notes, Markdown and Mermaid documents, blood sugar and weight logs, vision boards, workout progress and preferences are saved in your browser’s local storage and IndexedDB. They stay on your device and are never sent to us. Anyone who uses the same browser profile can see them. Settings shows what each tool has saved and lets you delete it.

• Games. The games remember your sound and big-screen settings on this device; for the open tab, your seat and round, so a reload keeps your place; and, on this device, which seat you took in your last few rooms, so opening the link again offers to continue. A game’s room code and the players’ names are in its link after the “#”, which browsers never send, and nothing about a game (names, cards, moves) is sent to us or anyone else.
• PDF Reader. PDFs you open in the PDF Reader are kept in your browser (the last 20), so they reopen where you left them, with your highlights, notes and drawings beside them. The files never leave your device: backups and sync carry your marks, not the files, and form answers only travel in a backup when you include sensitive data. Opening a password-protected PDF asks for its password each time; it is never stored.
• Offline copy. Pages you open are kept in your browser so they open again without a connection. If you turn on “Keep Binary Decimal on this device” in Settings → Offline, your browser also downloads the site’s own files (its code, fonts and the extras you pick) from our host and keeps them. Those downloads only fetch our files and send nothing about you or your data. Turning it off deletes the copy.
• Backup. The backup page saves everything into one file that you download. We never receive it.
• Folder sync. If you turn it on, your browser writes your saved data to a folder that you pick on your computer. If that folder is inside Dropbox, Google Drive, OneDrive or iCloud Drive, that service copies it under its own terms. We never receive it.

Analytics

We use Google Analytics 4, a service from Google, to learn which pages and features are used. With each page view it receives:

• the page’s address without anything after the “?” or “#”, so none of your inputs, and the page you came from, trimmed the same way;
• on the first page of a visit only, any campaign tags in the link you followed (utm_* and gclid);
• what your browser tells every site: device and browser type, screen size, language and an approximate location worked out from your IP address. Google says Google Analytics 4 doesn’t store IP addresses.

We also record a few actions, for example copying a share link, printing a result, starting a workout or exporting a vision board. These events carry simple labels such as the tool’s name, a workout goal or a number of tiles, never the numbers or text you type. The AI helpers record only which tool and helper were used (for example “Markdown editor, summarise”) and which kind of AI did it (“builtin”, or the provider of your own key, such as “openrouter”), never the text, the answer, the model, the key, the text’s length or its language. Health tools send nothing about your health: for example, the blood sugar log records only that a reading was added, and the GLP-1 calculator only that a forecast was shown, never the medication, dose or any value.

Cookies. Google Analytics sets first-party cookies named _ga and _ga_ followed by an ID, which tell one visit from another and last up to two years. The site doesn’t set any other cookies.

Turning it off. In Settings → Advanced privacy, switch off “Share anonymous usage stats”. In that browser, Google Analytics then doesn’t load at all: no requests go to Google and no analytics cookies are set, and the ones already set are deleted. The choice is saved in your browser like your other settings (so it travels with a backup or sync), and clearing the site’s data from Settings keeps it.

An AI key. Storing your own AI key doesn’t change this switch: Google Analytics stays on unless you turn it off, and it never receives your key, prompts or answers (see AI features with your own key).

Global Privacy Control. If your browser sends the Global Privacy Control signal (some browsers and extensions do, or have a setting for it), we treat it as “off”: Google Analytics doesn’t load, and Settings shows why.

You can also install Google’s Google Analytics opt-out add-on, block cookies for this site, or use a content blocker. Every tool works the same without analytics. Google handles this data under the Google Privacy Policy.

The contact and feedback forms

When you send a message through the contact form, what you type in it (your name and email if you add them, the topic, the message and, if you came from “Report a mistake”, the address of that page without your inputs) goes to Netlify, our host, which stores it and emails it to us. Netlify checks messages for spam. We use your message only to read it and reply, and we delete messages we no longer need. Please don’t include health details or other sensitive information. The form records a “message sent” event in analytics with the topic only.

The “Send feedback” sheet on each tool (which “Report a mistake” also opens) works the same way. It sends what you write (the message, whether the tool was useful if you pick one, and your email if you add it), the kind of feedback, the tool’s name and version, which build of the site you were on, and the address of the page without your inputs, and nothing else: not what you typed into the tool, and nothing you saved. It records a “feedback sent” event in analytics with the kind of feedback only.

Hosting

Netlify hosts the site. Like any web server, it receives your IP address, the address you requested and your browser’s details when a page loads, and keeps them in its logs for security and operations. See Netlify’s privacy policy.

Page speed. On the live site, Netlify also adds a small script of its own (Real User Monitoring) that measures how fast each page loads and responds. When you leave a page or switch tabs it sends Netlify the page’s address without anything after the “?” or “#” (so none of your inputs), your browser and operating system type, your screen size, whether it’s a phone or a computer, and the page’s load and response timings. Like any request, it reaches Netlify with your IP address. It sets no cookies. We use it to keep the site fast and to protect it from abuse. It isn’t Google Analytics, so the usage stats switch in Settings and Global Privacy Control don’t turn it off.

Content from other sites

Some features load content from other services, which then see your IP address and browser details:

• photos from Unsplash on the home page, in the vision board maker and in the Markdown editor’s cover picker;
• any image link you paste, which loads from the site it points to;
• mermaid.ink, if you use the Mermaid editor’s image link: the diagram is written into that link and drawn by mermaid.ink;
• MET Norway (the Norwegian Meteorological Institute), only if you turn on the weather forecast in Outfit of the Day: the request carries a rough place, rounded to about 10 km, and nothing else. See MET Norway’s terms of service.
• your own Nightscout site, only if you connect it to the blood sugar log: your browser asks it for your sensor readings, with the read-only token you gave in the request’s address. That site is yours (or your host’s), so it already holds the readings; nothing goes through us. The address and token stay in this browser. The log’s page is the only one allowed to contact a site we can’t name in advance.

The studies we cite and other linked sites are separate websites with their own privacy policies. Nothing is sent to them unless you follow a link.

The share buttons on blog posts and results are plain links too: no button, script or image from X, LinkedIn, Reddit, Facebook, WhatsApp, Bluesky or Threads loads on our pages. Only when you tap one does your browser open that site with the link shown before you share. A shared link never carries health or body numbers.

Google Calendar in Workstreams

Workstreams (our planner, /tools/workstreams) can sync its time blocks with your Google Calendar. It is off until you connect it, and we have no server, so nothing about it passes through us:

• Access. When you press Connect, Google asks you to allow it, in Google’s own window. Google then gives this page an access token that lasts about an hour. It is kept in that browser tab’s memory only: never saved on your device, in a backup or in sync, never in the page’s address, never sent to us. When it ends, pressing Sync asks Google again.
• What it may do. One permission: to make secondary calendars and manage their events (calendar.app.created). Workstreams uses it to make one calendar called Workstreams in your account, to add, change and delete the events for your time blocks in it, and to read the changes you make to those events, so they come back to your blocks. It can’t see or change your other calendars. Only if you turn on “Also show my other calendars”, it also asks to see your calendar list and read your events (calendar.calendarlist.readonly and calendar.events.readonly): their titles and times are shown on your week as busy times, read-only, kept in that tab’s memory and never stored.
• What is sent. When you press Sync, your browser sends your blocks straight to Google: each block’s title, day and times, its project and stream names, and Workstreams’ own ids for it. We never receive, store or see any of it, or anything from your Google account.
• What stays on your device. That you connected, the Workstreams calendar’s id, and a list of the events Workstreams made with their times, so the next Sync knows what changed. The calendar’s id is also kept with your Workstreams data, so your other devices use the same calendar through a backup or folder sync.
• Limited Use. Binary Decimal’s use of information received from Google APIs will adhere to the Google API Services User Data Policy, including the Limited Use requirements. Your Google data is used only to show and sync your calendar in Workstreams, in your browser. It isn’t transferred to anyone, read by people, used for ads, or used to train AI models.
• Stopping it. Disconnect in Workstreams’ Google Calendar sheet withdraws the access (or remove Binary Decimal at myaccount.google.com/permissions). The Workstreams calendar stays in your Google account until you delete it in Google Calendar. Google’s handling of your account is under Google’s privacy policy.

If you’d rather not connect an account, Workstreams also exports your blocks as an .ics file for any calendar app, and reads another calendar’s .ics file to show its busy times. Both happen in your browser; nothing is sent.

What we don’t do

We don’t have accounts or profiles. We don’t sell, rent or share personal data, and the site shows no ads and runs no advertising trackers.

Deleting your data

• Saved work: delete items in the tool, clear one tool’s data or everything in Settings, or clear the site data for binarydecimal.com in your browser’s settings, which removes everything the site saved. To keep a copy first, use the backup page.
• Sync folder: delete the folder you picked.
• AI key: “Remove key” in Settings → AI, or close the tab if you didn’t choose to remember it. What you sent to an AI provider is kept under that provider’s policy; ask them to delete it.
• Google Calendar: Disconnect in Workstreams (see Google Calendar in Workstreams), and delete the Workstreams calendar in Google Calendar to remove its events.
• Contact messages: ask through the contact form and we’ll delete them.
• Analytics: turn usage stats off in Settings → Advanced privacy (which also deletes the analytics cookies), or clear your cookies to start fresh. Google Analytics data isn’t linked to your name, so we can’t look up one person’s visits.

Children

The site isn’t directed at children under 13, and we don’t knowingly collect personal information from them. The kids’ growth calculator is for parents and carers, and what you enter in it stays in your browser.

Changes to this policy

When we change how the site handles data, we update this page and the date at the top. If a change is significant, we’ll say so on this page.

Contact

Questions or requests about your privacy: use the contact form.