Privacy Mask: Hide PII from ChatGPT, Claude, Gemini & Redact PDFs

Hide personal data before sending to ChatGPT, Claude or Gemini. Redact PDFs and scans. All locally in your browser.

Privacy Mask helps you hide personal and sensitive information before you submit an AI prompt. It runs on your own computer. Detection never sends your text anywhere. Optional usage sharing is off until you agree to it. Start on the Free plan with no account, or go Pro for unlimited hides and files. You stay in charge of sending. Privacy Mask never submits a prompt for you. Auto mode is off by default: with Auto off, review the findings and press Hide to insert placeholders. Turn Auto on in the side panel to hide detected data in the chat box after you pause typing or paste text. You can turn it off again at any time. Review the result and press Send yourself. HOW IT WORKS Write or paste your prompt the way you normally would. Open the Privacy Mask panel to review the text and detected items, checked on your device. With Auto off, choose what to hide and press Hide to put the masked version into the chat box. With Auto on, detected data is replaced automatically after you pause typing or paste text; review the placeholders before sending. If you try to send while a check is unfinished or that action just changed the text, Auto can hold the send so you can review it and press Send again. Each piece of sensitive data becomes a short placeholder, such as [EMAIL_1], [NAME_2], or [PHONE_1]. The link between a placeholder and its real value stays in your browser. Draft maps are session-scoped; maps for saved conversations stay in local extension storage across browser restarts until you use Clear session or uninstall. In supported chat replies, hover or focus a placeholder to reveal its value inside the extension. In the separate text editor, you can paste an answer back and restore values locally. PLANS Privacy Mask comes in two plans. Detection works the same way in both, locally in your browser; the plans differ only in how much you can hide each week. Free: 200 hides and 10 files per week, no sign-in needed. The counter lives in your browser and starts over seven days after the first hide or file export in that weekly window. Pro: unlimited hides and files. $9 per month or $60 per year, cancel any time from Manage subscription. Pro needs a Google sign-in so the plan follows you between computers. Stripe takes the payment, so no card details reach PaperWork. PaperWork's account service stores your account email, account ID and subscription status, never anything you hide. WHERE IT WORKS Privacy Mask adds a quick privacy step to the major AI chat assistants you already use. The full list of sites it runs on is shown in the permissions on this page, so you can check it before installing. It activates only on those sites and stays completely inactive everywhere else. On your bank, your email, or any other page, the extension does nothing at all. The document and text editors are separate. They can open over a supported chat or in their own extension window or tab. Open a file directly in the extension editor to review it locally before uploading it to any AI site; local editing needs no network connection. If you instead upload the original straight into an AI chat, that site may receive it immediately. Replacing it later does not undo that upload. WHAT IT DETECTS Privacy Mask looks for the kinds of data that cause real trouble when they end up in a prompt. Identity and contact details - Names of people and of business entities - Email addresses - Phone numbers, with international validation and additional format and context rules - Postal and street addresses Financial and banking data - Credit card numbers, checked with the Luhn algorithm - IBAN and BIC / SWIFT bank codes - Bank account numbers Government and tax identifiers - Supported national and tax ID formats for the United States, United Kingdom, Spain, Italy, France, Germany, the Netherlands, Russia, and the United Arab Emirates; checks vary by type, using checksums, format or nearby labels - Passport numbers - VAT numbers and the UAE Emirates ID Secrets and credentials - API keys and access tokens from common developer and cloud platforms - Database connection strings that carry a username and password - Bearer tokens and private keys Technical and other identifiers - Crypto wallet addresses - IPv4 and MAC addresses - Vehicle VINs and license plates - Dates and money amounts BUILT TO AVOID FALSE ALARMS A tool that masks everything that vaguely resembles an ID becomes useless fast. Privacy Mask uses patterns, validation and context to reduce false alarms. Credit cards pass the Luhn test. IBANs pass the mod-97 calculation. Some national IDs have checksum checks; others use format rules or nearby labels. Context-dependent rules look for words that identify a tax ID, passport or account number. These checks reduce mistakes but cannot eliminate them: review the findings and anything the detectors missed. DOCUMENTS: PDFS, SCANS AND IMAGES Sensitive data does not live only in typed prompts, so Privacy Mask includes a document editor. Open it from the side panel and load a PDF, JPG or PNG. You see the real pages and a list of what was found: type, value and page. - Every occurrence has its own Hidden / Visible switch. Two mentions of the same name are independent, and "Apply to all" changes them together only when you ask for it. - Draw a box over anything the rules missed, or select text and choose Hide selected text. Undo and redo cover both. Original and Result show the page before and after. - Export does not draw a black rectangle over the original text objects. It renders each page, erases the hidden pixels, and rebuilds the PDF from cleaned images. Original text objects, annotations, form fields, embedded attachments and source metadata are not copied. Download PDF produces image pages without searchable text. Attach to... uses local OCR to build a new text layer from visible words and placeholders, excluding words that touch hidden areas; that PDF can be searched and read as text. - The default file name has the hidden values stripped out of it, and the exported file carries no table of originals. - Download PDF writes the file to your computer. Nothing is sent anywhere and no chat is touched. - Attach to... is a separate, explicit action: you pick an open chat tab yourself and hand over the current reviewed version. The site can upload the attached file immediately, but Privacy Mask never presses Send for you. READS SCANNED PAGES TOO A scan is a picture, and a picture of a contract hides the same data as a typed one. The editor starts local text recognition when page images need checking, including scans and mixed text-and-image PDFs. Check page images lets you run it again. English, Russian and Spanish recognition data ship inside the extension. No download, no server, no optional model required. Recognition is not perfect and the editor does not pretend otherwise. Unchecked, empty and low-confidence pages stay marked as review-required. Review every page and use manual boxes for anything the recognizer missed. OFFICE FILES Word documents (.docx), spreadsheets (.xlsx) and CSV files go through the same review flow. The text inside them is scanned with the same detectors, and images embedded in those files can be checked as well. YOUR OWN TERMS Some sensitive words are specific to you: a project codename, a client alias, an internal product name. You can add your own terms, and Privacy Mask masks them next to the built-in detectors. Your custom terms are stored locally, like everything else. OPTIONAL: A LOCAL AI MODEL Rules and checksums handle the structured data well. For free-form writing, where a name or an address is defined by context rather than by shape, there is an optional local model called Privacy Filter. It is genuinely optional. Masking in chat, PDFs and Office files works with the built-in rules without it. Once installed, the local model also checks chat text and documents automatically alongside the rules. If you never install it, no model files are downloaded. If you do install it, this is what happens and it is worth reading before you click. The weights come from Hugging Face and are close to a gigabyte, downloaded once. You can also point the extension at a copy you already have on disk instead. Once installed, the model runs inside your browser. Your text is never uploaded to it, because there is nothing to upload to: the model is on your machine. You can compare what the rules found against what the model found, side by side, and decide. WHY LOCAL-ONLY MATTERS Many tools that promise privacy do their scanning on a server. To check your text, they first have to receive your text, which is the exact thing you were trying to avoid. Privacy Mask takes a different route. All detection happens in your browser, using pattern matching, checksums and, if you chose to install it, a model stored on your own disk. Your text never reaches a backend that could be breached, nothing you type is logged, and nothing is sold. If you want proof, open your browser's network tab while you work. Detection makes no remote inference requests. Other network activity includes the optional model download, Google sign-in and Pro account checks, Stripe payment pages, and files you explicitly attach to an AI site. If you choose to answer the use question, its fixed choices are sent; if you agree to Help improve Privacy Mask, a weekly summary of counts is sent, never prompt text, hidden values or file names. Chrome also opens an optional survey on paperwork.to when you uninstall. LANGUAGES Languages are set separately for different parts of the extension. - Interface: English, Russian and Spanish. - Detection by format: many cards, IBANs, API keys, crypto addresses and IDs can be found by their shape, with validation where available. Examples include Spanish DNI and NIE and the Italian codice fiscale. Other ID rules, including German and Dutch tax or personal numbers, also require nearby labels. - Detection by context, where a value is identified from nearby words, such as a name or tax number after a label: mainly English and Russian, plus selected labels in other languages, such as Spanish address labels. Coverage varies by rule. - Recognition of scanned pages: English, Russian and Spanish. You pick this per document, separately from the interface language. WHO IT HELPS People paste real, sensitive material into AI tools every day: - Support agents pasting tickets full of customer names, emails, and order details - Developers pasting code, logs, and config files that still hold API keys and connection strings - Finance and operations teams pasting invoices, bank statements, and contracts - Anyone drafting an email or document that names a real person Privacy Mask lets you keep using AI for this work while keeping the personal and financial details to yourself. ABOUT PAPERWORK PaperWork builds document AI for banks, lenders, and fintech companies. Our main product reads financial documents such as bank statements, invoices, and KYC files, and turns them into structured, verified data. Handling that information carefully is the center of what we do, not a footnote to it. Privacy Mask grew out of the same concern. We wanted a way to use everyday AI tools without exposing the personal and financial data we are trusted to protect, so we built one. PaperWork sits where AI, financial technology, and data privacy meet, and this extension carries that focus into daily use: keep the help that AI gives you, without giving away the data behind it. You can learn more about our work at paperwork.to. WHAT PRIVACY MASK DOES NOT DO - It does not submit your prompts. With Auto off you press Hide; with Auto on it inserts placeholders automatically. You decide when to send. - It does not collect, store, or transmit your text off your device. - It does not send usage summaries unless you agree to Help improve Privacy Mask. You can turn sharing off in the side panel. - It does not load or execute remote code. The optional model download fetches data files only, verified against known checksums. - It does not require the optional model. Everything needed for rule-based masking ships inside the extension. A NOTE ON PERMISSIONS Privacy Mask asks only for what the job requires. - Access to the supported AI chat sites, so it can read the input field, scan your prompt and put the masked version back. - Local storage for settings, custom terms and saved-conversation placeholder maps; session storage for draft maps. - Unlimited storage, because the recognition data and the optional model are far larger than the small default quota. - A local offscreen step, used to process PDFs and images away from the page. - Access to huggingface.co, used for one thing only: downloading the optional model when you ask for it. If you never install the model, this access is never used. - Identity, used only to open the Google sign-in window when you choose the optional Pro plan. The Free plan never uses it. None of this sends your text to a server we run. PaperWork services handle the optional account, answers and count summaries described above, and the optional removal survey, never your prompt text or hidden values. GETTING STARTED Install the extension, open one of the supported AI sites, and write a prompt. Open the Privacy Mask panel, review what it found, and press Hide. Or turn on Auto to hide detected data after you pause typing. Review the result and send it yourself. On the Free plan there is nothing to sign up for and nothing to set up before it works. For documents, open the editor from the panel and load a file. COMMON QUESTIONS Does Privacy Mask send my text anywhere? No. Detection runs in your browser. No request leaves your machine to scan your text. Will it submit my prompt for me? No. It only inserts the masked text into the input field. You read it and decide when to send. What happens to the link between [EMAIL_1] and the real email? It stays in your browser and is used to reveal or restore values locally. Draft maps are session-scoped. Saved-conversation maps survive browser restarts until Clear session or uninstall. Do I have to download the model? No. Rule-based masking is the default and works on its own. The model is an extra you can install, skip, or remove later. Does the document editor really remove the data, or just cover it? It removes the content in the areas you hide. Pages are re-rendered with those pixels erased and the PDF is rebuilt from cleaned images. Download PDF has no searchable text; Attach to... adds a new OCR text layer that excludes hidden areas and includes placeholders. Review all pages for data the detectors or OCR may have missed. Does it work in languages other than English? Partly, and it is worth knowing where the line is. Many fixed-format values can be found regardless of the language you write in. Some IDs and other values also need nearby labels. Context rules mainly cover English and Russian, with selected labels in other languages. The interface is English, Russian and Spanish, and scans can be recognized in those three. How much does it cost? The Free plan covers 200 hides and 10 files a week with no account. Pro is unlimited for $9 a month or $60 a year, with a Google sign-in and payment through Stripe. You can cancel any time from Manage subscription. Privacy Mask comes with a Free and a Pro plan, and the way it handles data is set out in full in our privacy policy. If a claim on this page matters to you, you can check it yourself, because the work happens where you can watch it: in your own browser.