AI Skill Report Card

Detecting File Types

A-82·Apr 25, 2026·Source: Extension-page

Detecting File Types with AI

Rapidly identify file content types using deep learning models, even when file extensions are missing or incorrect.

15 / 15
Bash
# Install magika pip install magika # Detect single file magika document.pdf # Scan directory recursively magika -r /path/to/files # Get JSON output with confidence scores magika file.txt --json --output-score
Recommendation
Add edge cases like handling corrupted files, empty files, or files that return 'unknown' types
12 / 15

Basic Detection:

  1. Install magika CLI or Python package
  2. Point to file/directory path
  3. Review detected content type and confidence score
  4. Use appropriate prediction mode based on accuracy needs

Batch Processing:

Progress:
- [ ] Collect file paths or directory
- [ ] Choose prediction mode (high/medium/best-guess)
- [ ] Run detection with appropriate output format
- [ ] Filter results by confidence threshold
- [ ] Process files based on detected types

Python Integration:

Python
from magika import Magika m = Magika() # Detect from file path result = m.identify_path('document.pdf') print(f"Type: {result.output.label}") print(f"MIME: {result.output.mime_type}") print(f"Confidence: {result.output.score}") # Detect from bytes content = open('file.bin', 'rb').read() result = m.identify_bytes(content) # Detect from stream with open('data.csv', 'rb') as f: result = m.identify_stream(f)
Recommendation
Include templates for common integration patterns (web upload validation, file organization scripts, security scanning pipelines)
17 / 20

Example 1: Input: magika suspicious_file.txt Output: suspicious_file.txt: Windows PE executable (executable)

Example 2: Input: magika --json --output-score data.unknown Output:

JSON
{ "path": "data.unknown", "result": { "value": { "output": { "label": "csv", "description": "CSV document", "mime_type": "text/csv", "score": 0.99 } } } }

Example 3: Input: magika -r ./uploads/ --format "%p: %l (%s%%)" Output:

./uploads/doc1.pdf: pdf (99%)
./uploads/image.jpg: jpeg (97%)
./uploads/script.py: python (98%)
Recommendation
Expand completeness with fallback strategies when Magika fails and alternative tools for specialized file types
  • Use prediction modes appropriately: high-confidence for security scanning, best-guess for general classification
  • Check confidence scores: Scores below 0.8 may need manual review
  • Validate critical files: For security applications, combine with additional validation
  • Batch process efficiently: Use recursive scanning for directories rather than individual file calls
  • Handle generic labels: Files returning "Generic text" or "Unknown binary" may need fallback detection
  • Consider file size: Magika analyzes only file headers/beginnings, so works on large files efficiently
  • Don't rely solely on extensions: Magika detects actual content, not filename extensions
  • Don't ignore confidence thresholds: Low-confidence results may be inaccurate
  • Don't process streaming data without buffering: Use identify_stream() for file handles
  • Don't assume 100% accuracy: Even with 99% accuracy, validate critical file types
  • Don't skip error handling: Check result status before accessing detection values
  • Don't use for malware analysis alone: Magika detects file types, not malicious content
0
Grade A-AI Skill Framework
Scorecard
Criteria Breakdown
Quick Start
15/15
Workflow
12/15
Examples
17/20
Completeness
10/20
Format
15/15
Conciseness
13/15