🔥 FlameCSV 🔥

Fully-featured high performance CSV library for .NET with a simple API, deep customization options, and built-in support for UTF8, nativeAOT, and more. Read CSV at multiple gigabytes per second on consumer hardware, and write arbitrarily large amounts of CSV with near-zero allocations. FlameCSV leverages modern .NET patterns and libraries such as spans, SIMD hardware intrinsics, memory/string pooling, pipes and buffer writers, and is built from the ground up to provide an easy-to-use high performance experience.

FlameCsv is consistently the fastest .NET CSV library in the available benchmarks. The library has thousands of tests, and critical paths have been fuzz-tested with SharpFuzz.

See the documentation for more information and examples.

Features

• 💡 Ease of Use
  • Simple API for reading and writing CSV
  • Built-in support for common CLR types
  • Supports both synchronous and asynchronous operations
  • Flexible; read or write almost any data source
  • Automatic newline detection
  • UTF-8/ASCII support to read/write bytes directly without additional transcoding
  • Supports hot reload
• 🚀 High Performance
  • Optimized for speed and low memory usage
  • Specialized SIMD-accelerated parsing and unescaping
  • Batteries-included internal caching and memory pooling for near-zero allocations
  • Reflection code paths that rival and exceed manually written code in performance
• 🛠️ Deep Customization
  • Read or write either .NET objects, or raw CSV records and fields
  • Attribute configuration for header names, constructors, field order, and more
  • Support for custom converters and converter factories
  • Read or write multiple CSV documents from/to a single data stream
• ✍️ Source Generator
  • Fully annotated and compatible with NativeAOT
  • Supports trimming to reduce application size
  • Debuggable source code instead of compiled expressions
  • Compile-time diagnostics instead of runtime errors

Example

using FlameCsv; const string data = """ id,name,age 1,Bob,42 2,Alice,37 3,"Bond, James",39 """; List<User> users = []; // read objects from the string foreach (var user in CsvReader.Read<User>(data)) { users.Add(user); } // write to stream using a different delimiter await CsvWriter.WriteAsync( new StreamWriter(Stream.Null, Encoding.UTF8), users, new CsvOptions<char> { Delimiter = '\t' }, cancellationToken);

Changelog

0.3.0

• Breaking: Newline parsing is more lenient (e.g. \r\n can parse \n and \r as well), newline no longer nullable
• Breaking: Surrogate chars not supported in dialect
• Added support for flags enums in both reflection and source generated converters
• Added AVX-512 support for parsing
• Improved unescaping performance by up to 50%
• Added fuzz testing projects

0.2.0

• Breaking: Removed Async-suffix from CsvReader methods that support synchronous enumeration
• Breaking: Removed CsvUnhandledException, value enumerators now throw without wrapping the exception
• Added support for EnumNameAttribute
• Added enum converter source generator
• Added UTF-8 BOM skipping
• Fixed char converter inconsistencies on non-ASCII inputs
• Removed unnecessary SIMD instructions when parsing chars

0.1.0

Initial release.