BlurrA Chrome extension for AI chats
AI doesn’t need your real name to help.
Blurr catches names, ID numbers, cards and phone numbers in your message before you send it, and swaps them for placeholders. It all happens on your device, and the AI still answers the question.
For Chrome on a computer. No account needed.
A message with a name and several numbers is typed into an AI chat. Blurr underlines each personal detail and lists them in its panel. The details blur and turn into placeholders such as PERSON_1. The message is sent, and the AI replies using the placeholders.
- 01You write your message as usual.
- 02Blurr underlines the personal details it finds.
- 03Its panel lists them. You choose what to replace.
- 04Each detail blurs into a placeholder.
- 05You send. The real details stay with you.
- 06The AI answers without ever seeing them.
Shown without motion: below, your message with the details Blurr found; above, what was sent and the AI’s reply.
The findings are the real output of Blurr’s detection for this message. The chat is a generic one drawn for this page.
01
Real situations
The moments when a message carries more than the question.
Tighten up my résumé for a nursing job. I'm Dana Whitlock, 1428 Maple Street, Apt 3B, Springfield, IL 62704, 202-555-0147, [email protected].
Tighten up my résumé for a nursing job. I'm PERSON_1, ADDRESS_1, PHONE_1, [email protected].
- Name
- Home address
- Phone number
- Email address
Can I afford an $18,000 car loan on $4,200 a month? For the application: Marcus Ellery, SSN 123-45-6789, card 4111 1111 1111 1111.
Can I afford an $18,000 car loan on $4,200 a month? For the application: PERSON_1, SSN SSN_1, card CARD_1.
- Name
- Social Security number
- Card number
- Financial information
Explain my blood test: hemoglobin 9.8 g/dL, ferritin 6 ng/mL. The patient is Priya Lindgren, and the clinic calls her at 202-555-0148.
Explain my blood test: hemoglobin 9.8 g/dL, ferritin 6 ng/mL. The patient is PERSON_1, and the clinic calls her at PHONE_1.
- Name
- Phone number
- Health information
Draft a small-claims complaint: my landlord kept my $1,500 deposit. My name is Dana Whitlock and I live at 1428 Maple Street, Apt 3B, Springfield, IL 62704.
Draft a small-claims complaint: my landlord kept my $1,500 deposit. My name is PERSON_1 and I live at ADDRESS_1.
- Name
- Home address
Shorten this note to a client: “Hi Jordan Reyes, your invoice is ready. Questions go to [email protected] or 202-555-0149.”
Shorten this note to a client: “Hi PERSON_1, your invoice is ready. Questions go to [email protected] or PHONE_1.”
- Name
- Email address
- Phone number
02
What the AI sees
The question is the same. The difference is what ends up on someone else’s servers.
Help me write to my landlord: the heating has been broken for two weeks. I'm Dana Whitlock, [email protected], 202-555-0147. I live at 1428 Maple Street, Apt 3B, Springfield, IL 62704.
With Blurr: Help me write to my landlord: the heating has been broken for two weeks. I'm PERSON_1, [email protected], PHONE_1. I live at ADDRESS_1.
Drag, or use the arrow keys
03
Your text stays with you
Runs on your device
Everything Blurr checks is checked in your browser.
No account, no analytics, no tracking
There is nothing to sign up for and nothing to log in to. The extension and this website carry no analytics and no tracker.
We have no server for your text
We run no server that receives your messages, what Blurr finds in them, or your activity.
Open answers about 23 AI sites
The same four questions for every AI chat site Blurr works on: training, retention, opting out and deleting, answered from each company’s own pages.
04
What Blurr catches
Detection is best effort: it can miss a detail or flag something harmless, so the final decision is always yours.
- Names, in any letter case and scriptis replaced with
PERSON_1 - Email addressesis replaced with
[email protected] - Phone numbersis replaced with
PHONE_1 - IIN and BINis replaced with
IIN_1 - Passport and ID card numbersis replaced with
PASSPORT_1 - Bank card numbersis replaced with
CARD_1 - IBAN and bank accountsis replaced with
BANK_1 - Home addressesis replaced with
ADDRESS_1 - Vehicle platesis replaced with
PLATE_1 - API keys and passwordsis replaced with
API_KEY_1
05
Works on 23 AI chat sites
Blurr runs only on the sites listed here and does nothing anywhere else. Each name opens what that site does with your chats.
06
Questions and answers
Does Blurr see my chats?
The extension reads the chat box on supported sites, because that is how it checks it, and that reading happens only on your device. We, the people who make Blurr, receive nothing: not your chats, not what was found in them, not your activity. There is no server for it to go to.
What does Blurr download, and from where?
One thing: the AI model that recognises names. It is about 181 MB, comes from Hugging Face (huggingface.co) at a fixed version, and every file is checked against a known SHA-256 fingerprint before it is used. Hugging Face sees your IP address, as any download server does. It receives nothing about what you type.
Which sites does it work on?
On the 23 AI chat sites listed on this page, among them ChatGPT, Claude, Gemini, Microsoft Copilot, DeepSeek, Perplexity and Alice AI. On every other site it does nothing.
Does it work offline?
Blurr’s own checks need no connection. The rule-based checks work from the first minute, and the name model works offline once it has been downloaded. The AI chat site itself, of course, still needs the internet.
What about files I attach?
Blurr reads text and code files, PDFs that have a text layer and Word documents (DOCX), up to 15 MB, on your device, and lists what it finds. You can attach a text copy with the details replaced, or the original. A scanned PDF, a picture or any other format cannot be checked, and Blurr tells you so instead of calling it clean.
How is this different from the AI’s own privacy settings?
Those settings decide what the company does with a chat after it has received it: whether it trains on it and how long it keeps it. Blurr acts earlier. A detail you replace never reaches the company at all. The two work together: see what each site does with your chats.
Is Blurr free?
Yes. Blurr is free.
How do I report a problem?
Open the tab with the AI chat where the problem is, click the Blurr icon in Chrome’s toolbar and choose “Copy diagnostic report”. The report is now copied: paste it into a message to [email protected]. It describes the page’s structure and what Blurr decided. It never contains text from the page or from your message, or anything Blurr found.
Does Blurr ever send a message for me?
No. Replacing a detail changes the text in the chat box and nothing more: you press send. The one exception is “Send anyway”, which lets through a send of yours that Blurr had stopped.
Which browsers does it work in?
Chrome on a computer, version 116 or newer. Edge, Brave and Opera are built on the same engine (Chromium) and should work, but we have not tested them. There is no version for phones.
Try it on your next question.
Coming soon to the Chrome Web Store