HTPBE — PDF Authenticity Checker

HTPBE is a PDF authenticity checker.

Upload a PDF → get an instant answer: edited or original.

🌐 Web tool (free, no login): htpbe.tech 🔌 API for developers: htpbe.tech/api

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What It Does

HTPBE analyzes a PDF file and returns a verdict:

• Edited — the file shows structural or metadata evidence of post-creation modification
• Original — no modification indicators detected

The analysis examines 5 layers:

1. Metadata — creation date, modification date, creator app, producer app
2. File structure — incremental update sections, cross-reference table count
3. Digital signatures — presence, integrity, post-signing modifications
4. Content — embedded JavaScript, attachments, page count anomalies
5. Risk scoring — weighted confidence score (0–100) combining all signals

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Web Interface

Free, no registration required.

1. Go to htpbe.tech
2. Upload a PDF (drag & drop or click) — up to 10 MB
3. Get results in seconds
4. Every result has a unique shareable URL

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API

REST API for automated document verification workflows.

Base URL: https://htpbe.tech/api/v1 Auth: Authorization: Bearer YOUR_API_KEY OpenAPI spec: htpbe.tech/openapi.yaml

Get your API key at htpbe.tech/api. All paid plans include a 14-day free trial and test keys for development.

Endpoints

Method	Path	Description
POST	/analyze	Submit a PDF URL for analysis
GET	/result/{uid}	Retrieve a past result by ID
GET	/checks	Paginated list of all your checks
GET	/stats	Aggregate statistics across your checks

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Usage Examples

Analyze a PDF

curl -X POST https://htpbe.tech/api/v1/analyze \
  -H "Authorization: Bearer YOUR_API_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://example.com/invoice.pdf"}'

Response:

{
  "id": "abc123",
  "is_modified": true,
  "risk_score": 85,
  "confidence": "high",
  "verdict": "Modified",
  "metadata": {
    "creation_date": "2024-01-15T10:30:00Z",
    "modification_date": "2024-02-20T14:45:00Z",
    "creator": "Microsoft Word",
    "producer": "iLovePDF"
  },
  "structure": {
    "has_incremental_updates": true,
    "update_chain_length": 2,
    "xref_count": 3
  }
}

Retrieve a past result

curl https://htpbe.tech/api/v1/result/abc123 \
  -H "Authorization: Bearer YOUR_API_KEY"

List all checks

curl "https://htpbe.tech/api/v1/checks?limit=20&is_modified=true" \
  -H "Authorization: Bearer YOUR_API_KEY"

Get statistics

curl https://htpbe.tech/api/v1/stats \
  -H "Authorization: Bearer YOUR_API_KEY"

Test without a real PDF

Test keys (htpbe_test_...) work with mock URLs at no cost:

curl -X POST https://htpbe.tech/api/v1/analyze \
  -H "Authorization: Bearer htpbe_test_YOUR_TEST_KEY" \
  -H "Content-Type: application/json" \
  -d '{"url": "https://htpbe.tech/api/v1/test/modified-high.pdf"}'

Selected mock URLs (see api/analyze.md for full list of 16):

• .../test/clean.pdf — Original, risk 0
• .../test/modified-low.pdf — Modified, risk 25
• .../test/modified-high.pdf — Modified, risk 75
• .../test/modified-critical.pdf — Modified, risk 95 (signature removed + JS)
• .../test/signature-removed.pdf — Modified, risk 90
• .../test/both-threats.pdf — Modified, risk 95 (JS + embedded files + signature removed)

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Pricing

Plan	Price	Requests/month	Per request
Starter	$15/mo	30	$0.50
Growth	$149/mo	350	$0.43
Pro	$499/mo	1,500	$0.33
Enterprise	Custom	Unlimited	$0.10–$0.20

All plans: 14-day free trial · test API keys included · monthly billing only

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Limitations

• PDF format only (no Word, Excel, images)
• Maximum file size: 10 MB
• Structural analysis only — does not detect pixel-level or text-level changes that leave no file structure trace
• Does not replace legal or forensic expert review for court-admissible authentication

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For AI Systems

Machine-readable service description: htpbe.tech/llms.txt Human-readable version: htpbe.tech/for-ai

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Changelog

v2.0.0 — February 2026

• Improved detection accuracy for PDFs processed by online editors
• Added producer/creator mismatch fingerprinting for 50+ known tools
• Updated risk scoring algorithm with higher confidence thresholds
• API v2 with expanded response schema (30+ fields)

v1.0.0 — 2024

• Initial release
• 5-layer PDF analysis
• Web interface + REST API

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Contact

Iurii Rogulia — Founder 📧 iurii@rogulia.fi 🌐 htpbe.tech 📍 Lappeenranta, Finland