nietras/Sep
World's Fastest .NET CSV Parser. Modern, minimal, fast, zero allocation, reading and writing of separated values (`csv`, `tsv` etc.). Cross-platform, trimmable and AOT/NativeAOT compatible with blazing fast SIMD vectorized parsing. observed · 2026-08-28
Health v2 · maintenance only
97/100
- Activity 98
- Release rhythm 98
- Longevity 92
How is this computed?
round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10) — computed 2026-09-02. Adoption (stars, forks) is never an input.
- gap_med: 17.5
- age_days: 1294
- days_rel: 16
- days_push: 16
- n_releases_24m: 29
Adoption not part of the score
1467 stars · 53 forks observed · 2026-08-28
What it is AI-extracted, prompt v1, taxonomy v1, 2026-08-30, confidence not recorded
Sep is a modern, minimal .NET library for reading and writing separated values (CSV, TSV, etc.) with zero allocations and SIMD-vectorized parsing. It targets machine learning and data pipeline use cases and is cross-platform, trimmable, and AOT/NativeAOT compatible.
Use cases
- parse large csv files fast in .net
- read tsv files with zero allocations
- write csv files in c#
- load machine learning datasets from csv
- high performance csv parsing with simd
- multithreaded csv parsing in dotnet
When to choose
- you need maximum CSV/TSV parsing throughput in .NET
- you want zero-allocation, AOT-compatible parsing for ML pipelines
- you prefer a minimal, opinionated API over configurable CSV readers
When to avoid
- you need extensive CSV dialect options, automatic escaping, or RFC 4180 edge-case handling out of the box
- you are not on .NET 7+ / C# 11+
- you need a full data manipulation library rather than a parser
Facets
library · maturity active
parser serialization data-science files data-science developer-tools machine-learning dotnet cross-platform csv tsv simd zero-allocation performance separated-values
3 sources
- readme: https://github.com/nietras/Sep · fetched 2026-08-28 · 27c93d6630aa
- homepage: http://nietras.com · fetched 2026-08-29 · cf611f7c8e89
- site_page: https://nietras.com/about · fetched 2026-08-29 · 108c513a45bd
Member repositories
| Repository | Role | Health v2 |
|---|---|---|
| nietras/Sep | main | 97 |
For agents
Data as of 2026-08-30T08:39:29.467469+00:00 · Report a problem