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FastCSV FastCSV

Welcome to FastCSV

Introduction

FastCSV is a high-performance CSV parser and writer for Java licensed under the MIT open source license. It is designed to not only be fast and lightweight but also to be compliant with the CSV specification RFC 4180.

Benchmark

Benchmark

This selected benchmark is based on the Java CSV library benchmark suite.

Real-world CSV data

Reading and writing perfectly formatted CSV data is straightforward. However, real-world CSV data is often not perfectly formatted. See Java Csv Comparison Project on how CSV libraries handle real-world CSV data and how FastCSV compares to other libraries.

Use Cases

The primary use cases are:

  • In big data applications: efficiently reading and writing data on a massive scale.
  • In small data applications: serving as a lightweight library without additional dependencies.

Features

The main features of FastCSV include:

  • Enables ultra-fast reading and writing of CSV data
  • Has zero runtime dependencies
  • Maintains a small footprint
  • Provides a null-free and developer-friendly API
  • Compatible with GraalVM Native Image
  • Delivered as an OSGi-compliant bundle
  • Actively developed and maintained
  • Well-tested and documented
  • Crafted with natural intelligence, ❤️, and AI assistance ✨

CSV specific

  • Compliant with RFC 4180 – including:
    • Newline and field separator characters in fields
    • Quote escaping
  • Configurable field separator
  • Supports line endings CRLF (Windows), LF (Unix) and CR (old macOS)
  • Supports unicode characters

Reader specific

  • Supports reading of some non-compliant (real-world) data
  • Preserves line break character(s) within fields
  • Preserves the starting line number (even with skipped and multi-line records) – helpful for error messages
  • Auto-detection of line delimiters (CRLF, LF, or CR – can also be mixed)
  • Configurable data validation
  • Supports optional header records (access fields by name)
  • Supports skipping empty lines
  • Supports skipping non-CSV header (either by a fixed number of lines or by peeking data)
  • Supports commented lines (skipping & reading) with configurable comment character
  • Configurable field modifiers (e.g., to trim fields)
  • Flexible callback handlers (e.g., to directly map to domain objects)
  • BOM (Byte Order Mark) support (UTF-8, UTF-16 LE/BE, UTF-32 LE/BE)

Writer specific

  • Supports flexible quoting strategies (e.g., to differentiate between empty and null)
  • Supports writing comments

Requirements

  • for 3.x version: Java ⩾ 11 (Android 13 / API level 33)
  • for 2.x version: Java ⩾ 8 (Android 8 / API level 26)

Sponsoring and partnerships

YourKit

YourKit was used to optimize the performance and footprint of FastCSV. YourKit is the creator of YourKit Java Profiler, YourKit .NET Profiler, and YourKit YouMonitor.