Privacy Policy

The short version

The files you open and the numbers you type into Browser Tools stay on your device. They are processed by your own browser and are never uploaded to us or anyone else. That includes lab reports and health numbers. The exceptions, each described below and on its own page: the AI tools (Viral Hook Generator, Tailor My CV, Interview Prep and the optional AI chapter titles send your text to Google Gemini; the Accent Changer sends short voice clips to our voice server), IP & DNS Lookup, reminders you turn on (only times are sent) and encrypted sync (only encrypted data is sent).

At a glance

Health data: lab reports, diet and body numbers

We know health results feel more personal than a photo, so we built the health tools to never need a server. When you paste or drop a lab report, your own browser reads it and works out what each result means. The report, the values and the explanations are never sent to us, and we have no database where health results could be stored, sold or leaked.

• Saved history and family profiles (including Pro) live in your browser's local storage on this device. They only leave it if you turn on encrypted sync, and then only encrypted. Use “Delete all saved data” under My history, or clear this site's data, to remove them.
• Voice and food photos on the food, water and diet tools are processed in your browser by the Whisper speech model and the CLIP image model. The models are downloaded once from Hugging Face; your recording and photo are never uploaded.
• Paying for Pro never links your health data to your payment. Paddle and we know you bought a plan; nobody knows what your results are.
• Check it yourself: open the checker, turn off Wi-Fi, then paste a report. It still works, because nothing is sent anywhere. Developers can watch the browser's Network tab to confirm.
• The one thing we can see is that someone opened a page (standard server logs, below). We can't see what you typed into it.

Encrypted sync between devices (Health Pro)

If you turn on sync, your health data is encrypted in your browser before anything is sent, with a key we never have. Our server stores only the encrypted copy, so we can't read your results, names, medicines or what you ate, and neither could anyone who broke into our server. This is how it works, so you (or someone you trust) can check it; the code is in lib/vault/crypto.ts.

• Your passphrase never leaves your device. It is stretched into a key with PBKDF2-HMAC-SHA256 and 600,000 iterations (the figure OWASP recommends) and a random salt.
• A random 256-bit data key encrypts your data with AES-256-GCM, with a new random nonce every time. Each item is tied to its place and version, so the server can't swap or roll back items without your device noticing. Sizes are rounded up to whole kilobytes.
• What we store: the data key locked with your passphrase, the same key locked with your recovery key, a public key for family sharing, the salt, and the encrypted items under random ids. Plus your account email, needed to sign in.
• Recovery key: shown once when you set up sync, to download or write down. It unlocks your data if you forget your passphrase. If you lose both, the synced data is gone for good: we can't reset it or decrypt it. Your data on each device isn't affected.
• “Keep unlocked on this device” stores the derived keys in your browser in a form scripts can use but not read out. Don't use it on a shared computer. “Lock” removes them.
• Family medicine charts are encrypted with their own key. Each family member has their own key pair, and the chart key is locked separately for each member. Invite links carry the chart key's secret after the #, the part of a link browsers never send to a server; links work once and expire after 7 days. When the owner removes someone, the chart gets a new key that only the remaining members receive. We see which accounts share a chart, not what is in it.
• Limits we're honest about: we see when you sync and roughly how much data you have; members trust our server to hand out the right public keys (there's no key fingerprint check yet); and a weak passphrase is easier to guess if the encrypted copy were ever stolen, so use a long one.
• Deleting: “Delete my synced data from the server” removes your encrypted vault, its items and any family charts you started.

Files and text you use in the tools

Image, PDF, Word, video, text and calculator tools run entirely in your browser. When you close the tab, the data is gone. On pages without ads, the site's security policy also blocks the page from sending anything to another site.

Viral Hook Generator

The idea you type is sent from our server to Google's Gemini API, which writes the three hooks. We don't keep the idea or the hooks. Google handles the text under its own API terms; on Gemini's free tier, Google may use prompts to improve its products, so don't type anything private. A hashed version of your IP address is held in memory for a few minutes to enforce the usage limit. The image cards are drawn in your browser.

Tailor My CV and Interview Prep

Your CV file is read in your browser. When you press Tailor my CV or Prepare my answers, the text of your CV and the job ad go through our server to Google's Gemini API. We use Gemini's free tier: under Google's terms, Google may use what is sent and the answers to improve its products, and human reviewers may read them, so leave out details you don't want shared. We don't store your CV, the ad or the result. The full tailored CV comes back to your browser sealed (encrypted with our key) and is opened when you unlock it; it expires after 2 hours. Our logs record only which AI model answered and how long it took.

Accent Changer

Your file is transcribed in your browser. If you confirm that the voice is yours (or that you have the speaker's permission) and press the button, short clips of the voice (up to 15 seconds) and the transcript are sent through our server to our own voice server, which runs the open-source OpenVoice model on Hugging Face, to make the new audio. Nothing is stored there or by us; we count only the seconds you use, against your account, to keep the free allowance fair. The new audio is put back into your video in your browser.

Reminder notifications and WhatsApp reminders

The Medicine Reminder and the Pet Medicine Reminder keep everything on your device. If you turn on notifications (which arrive with the browser closed) or WhatsApp reminders, our server needs to know when to remind you, but not what for. For each medicine it stores only a random id, the times, the days it repeats and the start and end dates, plus your device's time zone. Medicine names, strengths, doses, notes and who they're for are never sent. The service refuses any schedule that contains anything else.

• Notifications (web push): we store your browser's push address. At each time we send only the time and the random ids, encrypted for your browser, through your browser maker's push service (Google, Mozilla, Apple or Microsoft). Your phone then looks the names up in its own storage to write the notification; if it can't, it shows “Time for a reminder”.
• WhatsApp: after you confirm your number with a code, we store the number and when you agreed. The message says only “Time for your 08:00 reminder”; open the page to see which medicine. It goes through WhatsApp, run by Meta, under its own terms. Codes are kept only in memory, hashed, for ten minutes.
• We keep a short record of which reminders went out (for three days) so nobody gets the same one twice.
• Reminders saved before 6 November 2026 included medicine names; on that date the reminder service deleted the names and kept only the times.

To stop and delete everything, press “Turn off” (notifications) or “Turn off and delete my number” (WhatsApp) on the page, or reply STOP to any WhatsApp reminder. The data is deleted from our server straight away.

Text to Speech

Text to Speech uses the voices built into your device, so we never receive your text. Voices marked “online” in the list are read by your browser's own cloud service (for example Google's in Chrome), which then receives the text under your browser's privacy terms; on-device voices keep it in your browser.

Comments and votes

The discussion under each tool is the one part of the site where what you type is meant to be public. When you post a comment we store, on our own server: the text, the name you picked (no account, no email), the time, and a hashed (not raw) version of your IP address, used for rate limits and to spot spam waves. Votes and reports are tied to a random anonymous id kept in a cookie on your device (bt_cv); we store only a one-way hash of it, so we can count one vote per browser without knowing who you are. Your browser also remembers your chosen name and your votes in local storage. Don't post personal information. To have a comment removed, use Report or contact us via the About page; moderators can remove any comment.

What is saved in your browser

• The invoice and quote tools remember your own business details, logo, currency and last invoice number in your browser's local storage, so you don't have to type them again. Clear your browser's site data to remove them.
• Some tools remember settings you chose. Nothing in local storage is sent to us.

Server logs

Like every website, our hosting keeps standard request logs (page address, time, browser type and IP address) for security, for a limited time.

Visitor statistics

We count visits with Umami, which we run on our own server, so the numbers never go to an analytics company. It sets no cookies and stores no IP addresses. For each page view it records the page address (without anything after a ? or #), the referring site, browser, operating system, device type, screen size, language and an approximate location (country, region and city) worked out from your IP address, which is then thrown away. Visits are grouped with a code made from a one-way hash that changes every month, so we can't recognise you across months or sites.

We also count a few actions so we know which tools are worth improving: that a tool was used, that a file was processed, that a download button was pressed, that someone opened the Pro dialog or started a checkout, and that a purchase completed (with the plan name only). These events carry only the tool's name and its section of the site, never your files, file names, text, numbers or payment details. If your browser sends “Do Not Track”, nothing is counted.

Advertising

There are no ads on the site at the moment. If we add them, this section will be updated first.

Accounts and payments

You can use every tool without an account. If you sign in (by an emailed one-time link, no password) or buy a report or plan, we store your email address on our server, with the reports and plans you bought (product, date, status) as reported by our payment provider. Sign-in links and session cookies (bt_session) are stored only as one-way hashes. Sign-in emails are sent through Resend.

Payments are handled by Paddle.com, our merchant of record, which collects your name, email, country and payment details under its privacy policy and charges any VAT or sales tax. We never see or store card numbers. Nothing you put into the tools (transactions, files, lab results) is sent to Paddle or to us when you pay: paid reports are built in your browser.

To delete your account and purchase history, contact us through the About page.

Children

The site isn't directed at children under 13 and doesn't knowingly collect their personal information.

Changes and contact

We'll update this page and its date when anything changes. Questions about privacy can be sent through the contact details on the About page.