---
title: "CSV requirements and preparation"
description: "Prepare a CSV that AI Glot can parse and later re-import, including file size, encoding, delimiters, headers, quotes and row structure."
canonical: "https://ai-glot.com/docs/platform/csv-files"
updated: "2026-08-09"
---

# CSV requirements and preparation

A clean export is the best protection against a failed import after translation.

## Requirements

| Requirement    | Supported behaviour                                          |
| -------------- | ------------------------------------------------------------ |
| File type      | `.csv` text file                                             |
| Maximum upload | **35 MB**                                                    |
| Encoding       | Strict UTF-8                                                 |
| Delimiter      | Comma or semicolon, detected automatically                   |
| Line endings   | LF, CRLF or CR                                               |
| Quoting        | RFC 4180 quotes, including embedded commas and line breaks   |
| Headers        | Every column needs a unique, non-empty header                |
| Rows           | At least one data row; every row must match the header width |

Physical blank rows and whitespace are preserved. A translated value may be longer than its source, so AI Glot keeps storage headroom above the 35 MB input limit for the completed file.

![CSV upload drop zone](/docs/screenshots/platform/translation-upload-empty.webp)

_Start with a CSV drop zone or the file picker_

## Prepare the export

1. **Keep stable identifiers**

   Include the key your destination system uses to match rows—such as a product ID or record ID—but do not select it for translation.
2. **Give columns unique names**

   Replace blank or duplicate headers before upload. Names such as `description_en` and `description_fr` are easier to map than repeated `description` columns.
3. **Export as UTF-8 CSV**

   In Excel or another spreadsheet, choose the UTF-8 CSV option. Renaming an `.xlsx` file to `.csv` does not convert it.
4. **Keep a source copy**

   AI Glot preserves structure, but the original export remains the safest rollback if the destination system rejects an import for its own rules.

## Rejected files

The browser checks the same structural rules as the translation engine before upload. It rejects empty files, invalid UTF-8, unclosed or unescaped quotes, empty or duplicate headers, missing data rows and rows with the wrong number of columns.

> **Warning: A CSV is not an Excel workbook**
>
> Formulas, formatting, multiple sheets, charts and cell types do not exist in CSV. Export the one table you want to translate; the current platform processes one structured CSV at a time.