FastCSV: fast, lightweight, and easy to use — the production-proven CSV library for Java.
It’s the most-starred CSV library for Java and trusted by leading open-source projects such as Apache NiFi, JUnit and Neo4j.

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