FastCSV

<p align="center"> <img src="fastcsv.svg" width="400" height="50" alt="FastCSV"> </p> <p align="center"> <strong>FastCSV</strong>: fast, lightweight, and easy to use — the production-proven CSV library for Java.<br/> It’s the most-starred CSV library for Java and trusted by leading open-source projects such as Apache NiFi, JUnit and Neo4j. </p> <p align="center"> <a href="https://javadoc.io/doc/de.siegmar/fastcsv"><img src="https://javadoc.io/badge2/de.siegmar/fastcsv/javadoc.svg" alt="javadoc"></a> <a href="https://central.sonatype.com/artifact/de.siegmar/fastcsv"><img src="https://img.shields.io/maven-central/v/de.siegmar/fastcsv" alt="Maven Central"></a> <a href="https://github.com/akullpp/awesome-java"><img src="https://awesome.re/mentioned-badge.svg" alt="Mentioned in Awesome Java"></a> </p> <p align="center"> <a href="https://github.com/osiegmar/FastCSV/actions/workflows/build.yml"><img src="https://github.com/osiegmar/FastCSV/actions/workflows/build.yml/badge.svg?branch=main" alt="build"></a> <a href="https://app.codacy.com/gh/osiegmar/FastCSV/dashboard?utm_source=gh&utm_medium=referral&utm_content=&utm_campaign=Badge_grade"><img src="https://app.codacy.com/project/badge/Grade/7270301676d6463bad9dd1fe23429942" alt="Codacy Badge"></a> <a href="https://codecov.io/gh/osiegmar/FastCSV"><img src="https://codecov.io/gh/osiegmar/FastCSV/branch/main/graph/badge.svg?token=WIWkv7HUyk" alt="codecov"></a> <a href="https://bugs.chromium.org/p/oss-fuzz/issues/list?sort=-opened&can=1&q=proj:fastcsv"><img src="https://oss-fuzz-build-logs.storage.googleapis.com/badges/fastcsv.svg" alt="oss-fuzz"></a> <a href="https://www.bestpractices.dev/projects/9141"><img src="https://www.bestpractices.dev/projects/9141/badge" alt="OpenSSF"></a> </p>

Features

Here are the top reasons to choose FastCSV — see fastcsv.org for the full feature list.

• Fast CSV processing — optimized for high-speed reading and writing
• Tiny footprint — only ~90 KiB, with zero runtime dependencies
• Developer-friendly API — clean, intuitive, and easy to integrate
• Well-documented — Quickstart guides and complete Javadoc
• High test coverage — including mutation testing for reliability
• RFC 4180 compliant — handles edge cases correctly
• Robust & maintainable — uses SpotBugs, PMD, Error Prone, NullAway, and Checkstyle to ensure code quality; never returns null unexpectedly
• Secure — fuzz-tested via OSS-Fuzz and following OpenSSF best practices
• Production-proven — trusted by open-source projects like JUnit
• Java 17+, Android 34+ compatible — including GraalVM Native Image and OSGi

Performance

Based on the Java CSV library benchmark suite.

Quick Start

Writing CSV

try (CsvWriter csv = CsvWriter.builder().build(Path.of("output.csv"))) {
    csv
        .writeRecord("header 1", "header 2")
        .writeRecord("value 1", "value 2");
}

Reading CSV

try (CsvReader<CsvRecord> csv = CsvReader.builder().ofCsvRecord(Path.of("input.csv"))) {
    csv.forEach(IO::println);
}

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For more examples and detailed documentation, visit fastcsv.org. If you find FastCSV useful, consider leaving a star!

License

MIT