n8n-nodes-file-type-detector

!Custom n8nnode File Type Detector

A powerful n8n community node that detects file types using magic bytes analysis, providing more reliable file type detection than MIME types alone.

Features

- Magic Bytes Detection: Uses the file-type library to analyze file headers for accurate type detection
- MIME Type Fallback: Falls back to original MIME type when magic bytes detection fails
- File Categorization: Automatically categorizes files (image, document, video, audio, archive, etc.)
- Comprehensive Analysis: Provides detailed file information including size, confidence level, and detection method
- Error Handling: Robust error handling with continue-on-fail support

Installation

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1. Open your n8n instance
2. Go to Settings → Community Nodes
3. Click "Install a community node"
4. Enter: n8n-nodes-file-type-detector
5. Click Install

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``bash
npm install n8n-nodes-file-type-detector
`

After installation, restart your n8n instance to load the new node.

Usage

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The File Type Detector node works with binary data and is typically used in workflows that process files:

`
File Source → File Type Detector → Process Based on Type
`

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#### 1. Analyze Uploaded Files
`
Webhook (File Upload) → File Type Detector → Switch (by file category)
`

#### 2. Process Email Attachments
`
Email Trigger → File Type Detector → Route by File Type
`

#### 3. Download and Analyze Files
`
HTTP Request (File Download) → File Type Detector → Store with Metadata
`

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#### Parameters

- Binary Property (default: data): The name of the binary property containing the file data
- Fallback to Original MIME Type (default: true): Whether to use the original MIME type if detection fails
- Include File Categories (default: true): Whether to include categorized file types in the output

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The node adds a fileTypeAnalysis object to your data with the following structure:

`json
{
"fileTypeAnalysis": {
"originalMimeType": "image/png",
"fileName": "example.png",
"fileSize": 12345,
"detectionMethod": "magic-bytes",
"confident": true,
"detectedMimeType": "image/png",
"detectedExtension": "png",
"typeName": "png",
"fileCategory": "image"
}
}
`

#### Field Descriptions

| Field | Description |
|-------|-------------|
| originalMimeType | The original MIME type from the source |
| fileName | The original filename (if available) |
| fileSize | File size in bytes |
| detectionMethod | Method used: "magic-bytes" or "fallback" |
| confident | Boolean indicating confidence in detection |
| detectedMimeType | The detected MIME type |
| detectedExtension | The detected file extension |
| typeName | The type name (e.g., "png", "pdf") |
| fileCategory | File category (see categories below) |

#### File Categories

The node categorizes files into the following types:

- image: PNG, JPEG, GIF, BMP, WebP, SVG, etc.
- document: PDF, DOC, DOCX, TXT, RTF, etc.
- spreadsheet: XLS, XLSX, CSV, ODS, etc.
- presentation: PPT, PPTX, ODP, etc.
- video: MP4, AVI, MOV, WMV, etc.
- audio: MP3, WAV, FLAC, AAC, etc.
- archive: ZIP, RAR, 7Z, TAR, etc.
- code: JS, HTML, CSS, Python, etc.
- other: Files that don't fit other categories

Use Cases

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Validate that uploaded files match expected types, regardless of file extension manipulation.

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Route different file types to appropriate processing nodes (OCR for documents, thumbnail generation for images, etc.).

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Detect potentially malicious files that may have incorrect MIME types or extensions.

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Automatically organize files into folders based on their actual type rather than claimed type.

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Ensure data pipelines handle files correctly by knowing their true format.

Why Use Magic Bytes Detection?

Traditional MIME type detection can be unreliable because:

- File extensions can be changed by users
- Web servers may report incorrect MIME types
- Email systems may modify MIME types
- Malicious files may claim to be different types

Magic bytes detection analyzes the actual file content to determine the true file type, making it much more reliable for security and processing purposes.

Examples

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Workflow: Manual Trigger → HTTP Request → File Type Detector

!alt text

HTTP Request Configuration:
- URL: https://httpbin.org/image/png
- Response Format: File

Result: Detects the file as a PNG image with high confidence.

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Workflow: Email Trigger → File Type Detector → IF (by category) → Process Accordingly

IF Node Logic:
- If fileCategory equals "image" → Send to image processing
- If fileCategory equals "document" → Send to OCR processing
- Else → Log unknown file type

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Workflow: Webhook → File Type Detector → IF (confidence check) → Security Action

Security Check:
`javascript
// In IF node expression
{{ $node["File Type Detector"].json.fileTypeAnalysis.confident === false }}
`

If confidence is low, flag for manual review.

Development

Want to contribute or modify this node? See DEVELOPMENT.md for local development setup instructions.

Requirements

- n8n version: 1.0.0 or higher
- Node.js: 20.19 or higher (for development)

Dependencies

- file-type: For magic bytes file type detection
- n8n-workflow`: n8n workflow types and interfaces

License

MIT

Support

- Issues: Please report issues on GitHub Issues
- Documentation: Full documentation available in the n8n Community
- n8n Discord: Join the n8n Discord for community support

Contributing

Contributions are welcome! Please read our contributing guidelines and submit pull requests to our GitHub repository.

Changelog

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- Initial release
- Magic bytes file type detection
- File categorization
- Fallback to original MIME types
- Comprehensive file analysis output

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Made with ❤️ for the n8n community