Security Updated December 2025

How SafeRedact Protects Your Documents

A transparent look at our hybrid AI architecture: what data is processed, where it goes, and how we protect sensitive information.

6 min read

The Short Version

SafeRedact uses AI to detect sensitive information in your documents. Here's exactly what that means for your data:

Original files stay local

Original PDF files stay in your browser

Text sent to AI

Extracted text is analyzed by Claude AI

No file storage

We don't store your documents anywhere

Redaction is local

Clean file created in your browser

Our Hybrid Architecture

We use a hybrid approach that balances AI accuracy with privacy protection. Here's the step-by-step process:

1

Text Extraction (Your Browser)

When you upload a document, your browser extracts the text using PDF.js (for PDFs) or Tesseract.js OCR (for scanned documents). The original file stays in your browser memory.

Runs locally in your browser
2

AI Detection (Cloud)

The extracted text (with position coordinates) is sent to our API, which uses Claude AI to classify which items are sensitive: SSNs, names, addresses, phone numbers, etc. This is what enables accurate, context-aware detection.

Text sent to AI (not your original files)
3

Review & Redact (Your Browser)

The AI returns classification results. You review the detections, adjust as needed, and click Redact. The clean output file is generated entirely in your browser—a new PDF without the sensitive data.

Runs locally in your browser

What IS Sent to the Cloud

Encrypted text payload

When your document is processed, text content is encrypted with AES-256-GCM in your browser before transmission. What actually leaves your device is an encrypted blob—not readable text. Our serverless function decrypts it only to pass to Claude for classification, then re-encrypts the response.

// What's actually transmitted:

{
  "encrypted": "U2FsdGVkX1+vupppZksvRf8xY2FkZTk3NmI0ZjJh
                MGJlNzU4MzQ2YWI3YWE3YzRjMWNhYzM0MzE2NTU2
                NjMyMWU3ZDk4ZTdhN2YzODJmMDcyOGY0MGY5NTJl
                M2IwNmE5YjU3YzBhZjE0NWYzMTQyN2Q3YjI...",
  "iv": "mHp4VkXq9bN3ZwRt",
  "key": "xK9mP2vL8nQ4wS7yA3bC6dE0fG5hJ1kM..."
}

Your sensitive data (names, SSNs, addresses) is never transmitted in readable form.

The decrypted text is processed by Anthropic's Claude API, which does not store or train on API inputs. Data is processed in memory and immediately discarded. See Anthropic's Privacy Policy for details.

AES-256-GCM Encryption

Application-Layer Encryption

Defense-in-depth beyond standard TLS

SafeRedact implements AES-256-GCM encryption at the application layer, providing an additional security boundary beyond standard HTTPS/TLS encryption. Your document text is encrypted in your browser before transmission and decrypted only upon return.

1

Browser generates ephemeral key

A unique 256-bit AES key is generated for each request using the Web Crypto API

2

Text encrypted before transmission

Document text is encrypted with AES-256-GCM (Galois/Counter Mode) with authentication

3

Server decrypts for AI processing

Our serverless function decrypts, sends to Claude API, receives detections

4

Response re-encrypted

Detection results are encrypted before being sent back to your browser

Why this matters

  • • Protects against network-level interception
  • • Data never exists in plaintext outside your browser
  • • Each request uses a unique encryption key
  • • Same encryption standard used by banks and governments

Technical specifications

  • Algorithm: AES-256-GCM
  • Key size: 256 bits
  • IV: 96 bits (randomly generated)
  • Authentication: GCM auth tag (128 bits)

This dual-layer encryption (TLS + application-layer AES-256) ensures your sensitive document text is protected at every step of transmission, exceeding industry standards for data protection.

What Is NOT Sent

Original PDF files

Original PDF binary stays in your browser

Scanned PDFs

Original PDF stays local; only extracted text is sent

Document structure

Formatting, layout, fonts, embedded objects

Metadata

Author, creation date, filename, etc.

Important: We do not store documents on SafeRedact servers. There is no retention period because there is nothing retained. Processing is ephemeral—when you close the tab, it's gone.

How We Compare to Other Tools

Tool File Upload Detection Retention
SafeRedact Text only AI (Claude) None
Adobe Acrobat Pro Local Regex patterns N/A
Smallpdf Full file Manual only 1 hour
iLovePDF Full file Manual only 2 hours
Redactable Full file AI Account storage

Visual: Where Your Document Goes

Most Tools
Your Computer
Full file
Their Server

Stored & processed

SafeRedact
Your Browser
Text only
AI (Anthropic)

Not stored · Discarded

SafeRedact advantage

AI-powered detection accuracy without uploading your actual documents. Other AI redaction tools require full file uploads and store documents in your account.

Tradeoff

Desktop apps like Adobe are fully local, but use basic pattern matching that misses context-dependent PII like names and addresses.

Compliance Considerations

Important Disclaimer

SafeRedact is not certified for HIPAA, GLBA, FERPA, or other industry-specific regulations. While we minimize data exposure, extracted text is processed via a third-party AI API. Organizations with strict compliance requirements should evaluate whether this meets their policies.

What this means for HIPAA

  • Text from documents is sent to Anthropic's API
  • Anthropic does not store API inputs by default
  • SafeRedact does not have a BAA in place
  • Consult your compliance officer before use with PHI

What this means for GDPR

  • Text processing involves a US-based data processor (Anthropic)
  • No persistent storage of personal data
  • Processing is ephemeral (no retention)
  • Review your DPA requirements

Frequently Asked Questions

Why not process everything locally?

We tried. Browser-based regex detection catches obvious patterns (SSNs, credit cards) but consistently misses context-dependent PII like names and addresses. AI provides dramatically better accuracy, which is the whole point of a redaction tool—you need to catch everything.

Is my data used to train AI models?

No. We use Anthropic's API, which does not use API inputs for model training by default. See Anthropic's Privacy Policy.

Why is this better than Smallpdf or iLovePDF?

Those tools upload your entire PDF to their servers and store it for 1-2 hours. We only send extracted text, and we don't store anything. Plus, they don't have AI detection—you have to manually find and mark every sensitive item.

Can I use SafeRedact offline?

Text extraction and redaction work offline, but AI detection requires an internet connection. Without it, the tool falls back to basic regex patterns (less accurate but still functional for SSNs, credit cards, etc.).

Is the redaction permanent?

Yes. SafeRedact renders your document as a new image with redaction boxes burned in. The sensitive content is never included in the output file—it's not hidden or covered, it simply doesn't exist in the exported document. The redacted content cannot be recovered by copy/paste, Photoshop, or any other method.

Ready to try it?

Start redacting in seconds

AI-powered detection with no document storage. Upload a PDF, review detections, download redacted. Free tier available.

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