---
title: Supported File Formats
description: File formats supported for data import in Twenty.
---

## Supported Formats

Twenty supports three file formats for import:

| Format | Extension | Notes |
|--------|-----------|-------|
| **CSV** | .csv | Recommended, most compatible |
| **Excel** | .xlsx | Modern Excel format |
| **Excel (Legacy)** | .xls | Older Excel format |

## File Requirements

| Requirement | Value |
|-------------|-------|
| **Encoding** | UTF-8 recommended |
| **Record limit** | 10,000 records per file |
| **Structure** | First row must contain column headers |
| **Content** | One object type per file |

## CSV Best Practices

- **Delimiter**: Use comma (`,`) or semicolon (`;`)
- **Text qualifier**: Use double quotes (`"`) for text containing commas
- **Line endings**: Windows (CRLF) or Unix (LF) both supported
- **Empty values**: Leave cells empty, don't use "NULL" or "N/A"

## Excel Best Practices

When exporting from Excel:
- Remove formulas (export values only)
- Delete empty rows at the end
- Ensure no merged cells
- Use the first sheet only

## Large Datasets

For datasets larger than 10,000 records:
- Split into multiple files
- Or use the [API import](/user-guide/data-migration/how-tos/import-data-via-api) for unlimited records

<Note>For very large migrations (100,000+ records), the API is significantly faster and more reliable than CSV imports.</Note>