What happens when your personal data leaks without you even knowing?

Every day, millions of companies process sensitive information: names, addresses, phone numbers, banking details. And every time that data is sent to a cloud-based AI tool to analyze a document or draft an email, there's a risk it could be stored, exposed, or mishandled.

On April 22, 2026, OpenAI released Privacy Filter: an open-source model specifically designed to detect and redact personally identifiable information (PII) in text. But the real question is: how can you use this technology without compromising the very privacy you're trying to protect?

At Montevive, our answer is clear: by bringing AI directly to your browser. No servers. No uploads. No risks.

What is Privacy Filter and why does it matter?

Privacy Filter is an artificial intelligence model trained to automatically identify personal data in any text:

• Full names (e.g., "John Smith")
• Postal addresses (e.g., "123 Main Street, Boston, MA")
• Phone numbers (e.g., "+1 555-123-4567")
• Email addresses (e.g., "user@company.com")
• Identity documents (SSN, passport numbers, driver's licenses)
• Banking details (IBAN, credit card numbers)
• And much more

Once detected, the model can redact this data (replace it with "█████") or simply flag it for human review.

The cloud processing problem

Traditionally, to use a model like this you would need to:

1. Send your document to a cloud server
2. Wait for the server to process the text
3. Receive the results back

But here's the problem: If you're sending sensitive information to a server to protect it, are you really protecting privacy? It's like mailing your house key to someone so they can install a more secure lock.

Our solution: 100% local browser demo

At Montevive, we've developed a functional demo that runs Privacy Filter entirely in your browser, without sending a single byte of information to any server.

🔒 Try it now: https://labs.montevive.ai/openai-privacy-demo/

How does it work?

1. Open the demo in your browser (Chrome, Edge, or any WebGPU-compatible browser)
2. Type or paste any text containing personal data
3. The model analyzes the text locally using your computer's GPU
4. See results in seconds without anything leaving your device

All processing happens on your machine. Not even we can see what you're analyzing.

Why this is a game-changer for privacy

1. Real privacy, not promises

When we say "privacy," it's not a marketing strategy. It's architecture:

• No backend: There's no server receiving your data
• No logs: We don't record activity or texts
• No tracking: We don't use third-party cookies or invasive analytics

2. Simplified regulatory compliance

If your company is subject to GDPR or other data protection regulations, processing personal data involves:

• Privacy impact assessments
• Data processing agreements
• Technical and organizational security measures
• Breach notifications to authorities

With local processing, many of these requirements are simplified because the data never leaves the data subject's control.

3. Speed without compromise

Thanks to technologies like WebGPU (GPU acceleration in browsers), the model runs quickly even on standard laptops. You don't need specialized hardware or ultra-fast connections.

Real-world use cases

For businesses

• HR departments: Redact resumes before sharing with hiring teams
• Customer support: Anonymize support tickets before exporting
• Legal/Compliance: Review contracts before uploading to document management systems
• Marketing: Clean databases of PII before AI analysis

For developers

• Testing: Generate test datasets without exposing real data
• Pre-processing: Clean logs or database dumps before debugging
• App integration: Add PII detection to web forms

For individuals

• Protect your privacy: Before pasting information into ChatGPT, Gemini, or any online AI
• Share documents: Redact sensitive data before sending PDFs via email
• Check exposure: Verify if a document contains information you didn't want to reveal

Why Montevive is a leader in secure AI

This project isn't accidental. At Montevive, we've been working on privacy-by-design AI for years:

Our principles

1. Local-first: If it can run locally, it shouldn't be in the cloud
2. Open source: All our technology is available on GitHub
3. No vendor lock-in: Use web standards (WebGPU, WebAssembly, ONNX)
4. Education: We share knowledge so others can build secure solutions

Technologies we master

• Transformers.js v4: Running Hugging Face models in browsers
• WebGPU: GPU acceleration for ML inference
• Edge architectures: AI on devices, not datacenters
• ONNX Runtime: Model optimization for production

Try the demo and verify it yourself

You don't have to trust our words. You can verify the privacy yourself:

1. Open your browser's DevTools (F12)
2. Go to the "Network" tab
3. Use the demo with sensitive data
4. You'll see that no HTTP requests are made during analysis

🔗 Live demo: https://labs.montevive.ai/openai-privacy-demo/

🎥 Explainer video:

💻 Source code: GitHub

The future of AI is private and decentralized

This project demonstrates something fundamental: you don't need to sacrifice privacy to use advanced artificial intelligence.

For years, the dominant narrative has been that powerful AI could only run in massive datacenters with thousands of GPUs. But reality is changing rapidly:

• Models are becoming more efficient
• Browsers include native GPU acceleration
• Consumer hardware is powerful enough

At Montevive, we believe the future of AI is local, private, and user-controlled. And we're building the tools to make it possible.

Want to implement private AI in your company?

If you're concerned about the privacy of your company's or customers' data, and want to explore how to implement AI solutions that comply with the strictest regulations, we're here to help.

At Montevive, we offer:

• Secure and private AI consulting: We assess your needs and design privacy-first architectures
• Custom solution development: We adapt models and tools to your specific use case
• Training: We train your team in AI and privacy best practices
• Privacy audits for AI systems: We review your current implementations

📧 Contact us: hola@montevive.ai

🌐 Learn more: montevive.ai

Montevive is a secure and private AI consultancy based in Granada, Spain. We help companies implement artificial intelligence without compromising the privacy or security of their data.