Use Binary Data Conversion Nodes to Transform Files

Use n8n's Extract From File and Convert to File nodes instead of writing custom parsing code. Extract From File reads XLSX, CSV, PDF, and more into JSON items; Convert to File does the reverse. They handle encoding, sheet selection, and header detection automatically, so a read-validate-write pipeline (for example XLSX to JSON to CSV) needs no manual parsing code.

What do the Extract From File and Convert to File nodes do?

n8n has dedicated nodes for reading and writing file formats: Extract From File reads spreadsheets (XLSX, CSV), PDFs, and more into JSON items, while Convert to File does the reverse. Use these instead of writing custom parsing code -- they handle edge cases like encoding, sheet selection, and header detection automatically.

Real-world example: A Google Drive trigger detects a new XLSX file uploaded by a client. You need to read the spreadsheet, validate the data, and generate a PDF report.

How do you build a file transformation pipeline?

Workflow structure:

[Google Drive Trigger] → [Extract From File] → [Code: Validate] → [Convert to File] → [Send Email]
     (new .xlsx)           (XLSX → JSON)         (check rows)       (JSON → CSV)      (attach CSV)

Extract From File node configuration:

Setting	Value
Operation	Extract From XLSX
Binary Property	data
Header Row	Enabled
Sheet Name	Sheet1

// Input: binary XLSX file with columns: Name, Email, Amount
// Output: JSON items
[
  { "Name": "Alice", "Email": "alice@co.com", "Amount": 1500 },
  { "Name": "Bob", "Email": "bob@co.com", "Amount": 3200 },
  { "Name": "Carol", "Email": "carol@co.com", "Amount": 750 }
]

Validation Code node:

const items = $input.all();
const valid = [];
const invalid = [];

for (const item of items) {
  if (item.json.Email && item.json.Amount > 0) {
    valid.push(item);
  } else {
    invalid.push({
      json: { ...item.json, error: 'Missing email or invalid amount' }
    });
  }
}

// Send valid items downstream, log invalid separately
return valid;

Convert to File node configuration for the output:

Setting	Value
Operation	Convert to CSV
Binary Property	report
File Name	validated_data.csv

The Send Email node then attaches the report binary property as validated_data.csv. The entire file transformation pipeline requires zero manual parsing code.

Which node should you use for each data task?

Summary. The most effective n8n data transformation workflows combine the right node type for each task: Edit Fields for renaming, Merge for joining, Split Out and Aggregate for reshaping cardinality, Code nodes only for genuine programming logic, and binary nodes for file format conversion. Defensive fallback expressions and consistent date handling via Luxon round out a robust data transformation toolkit.

Related: Flatten Deeply Nested API Responses · Use the HTTP Request Node as a Universal Connector