# CSV Formatter & Mapper

> CSV Formatter & Mapper is a high-performance, 100% client-side web application for visual drag-and-drop CSV field mapping, rule-based transformation, auto-increment sequence generation, and live table preview.

CSV Formatter & Mapper empowers businesses, developers, e-commerce operators, and data professionals to convert third-party or vendor CSV files into any required destination schema (e.g. OTS, SAP, Shopify, WooCommerce, ERP systems) directly inside the browser. All processing executes locally with zero server transmission.

## Core Capabilities
- [Visual Drag & Drop Mapping](https://csv.efestech.com/#mapping): Drag source column cards directly into target schema slots with instant visual feedback.
- [Auto-Match](https://csv.efestech.com/#automatch): 1-click fuzzy similarity matching between source headers and target fields.
- [Column Concatenation](https://csv.efestech.com/#concat): Merge multiple source fields (e.g., FirstName and LastName) with custom delimiters (e.g. space, hyphen) into a single target column.
- [Sequence Number & Auto-Increment ID](https://csv.efestech.com/#autoincrement): Generate custom IDs from any start number (e.g., 54, 55, 56...) with configurable steps, prefixes (e.g. `OTS-`), and zero-padding (e.g. `OTS-0054`).
- [Decimal & Comma Normalization](https://csv.efestech.com/#transforms): Standardize European and Turkish numeric amounts (`1.250,50` ➔ `1250.50`) for databases, ERPs, and accounting software.
- [Text Transformation & Cleaners](https://csv.efestech.com/#transforms): Uppercase, lowercase, capitalize, whitespace trimming, and numeric-only barcode extraction.
- [Static Constants & Fallbacks](https://csv.efestech.com/#rules): Fill missing required fields with static constants or default fallback values when empty.
- [Live Data Preview](https://csv.efestech.com/#preview): Real-time reactive preview of transformed records vs original source data with pagination and search.
- [Excel UTF-8 BOM & Delimiter Selection](https://csv.efestech.com/#export): Export to CSV with UTF-8 BOM (`\uFEFF`) to prevent character corruption in Microsoft Excel, supporting Semicolon (`;`), Comma (`,`), Tab (`\t`), and Pipe (`|`) delimiters.
- [Template Presets & LocalStorage Cache](https://csv.efestech.com/#presets): Save, organize, backup, and restore mapping configurations to turn recurring weekly CSV imports into a 1-second job.
- [35 World Languages with RTL Support](https://csv.efestech.com/#languages): Full localization in 35 world languages with complete right-to-left layout support for Arabic, Hebrew, Urdu, and Persian.

## Privacy & Security
- [Client-Side Architecture](https://csv.efestech.com/#privacy): 100% client-side execution using HTML5 File API and Web Workers. No CSV rows or customer records are ever uploaded to any remote server or external cloud.

## Technical Details
- [Full Technical Specification](https://csv.efestech.com/llms-full.txt): Comprehensive deep-dive documentation including rule schemas, transformation algorithms, delimiter detection, and architectural design.