# ClosedXML/ClosedXML

ClosedXML is a .NET library for reading, manipulating and writing Excel 2007+ (.xlsx, .xlsm) files. It aims to provide an intuitive and user-friendly interface to dealing with the underlying OpenXML API.

Repository: https://github.com/ClosedXML/ClosedXML
Canonical: https://ross.abutalabs.com/products/closedxml
Language: C#
License: MIT
License Family: permissive
Topics: closedxml, openxml, excel, xlsx, xlsm, hacktoberfest, hacktoberfest2020
Last push: 2026-07-26T18:48:45+00:00

## Health v2 (maintenance only)
Score: 87/100 (v2, computed 2026-09-03T02:20:16.233290+00:00)
- activity 94, release rhythm 71, longevity 100
- inputs: {"age_days": 3658, "days_push": 38, "days_rel": 39, "gap_med": 180, "n_releases_24m": 4}
- flags: none
- formula: round(0.45*activity + 0.35*rhythm + 0.20*longevity); archived -> min(score, 10)

## Adoption (not part of the score)
Stars 5686, forks 931 (observed 2026-08-28T04:09:27.897836+00:00)

## What it is
ClosedXML is a .NET library for reading, manipulating, and writing Excel 2007+ (.xlsx, .xlsm) files. It provides an intuitive, user-friendly API on top of the underlying OpenXML SDK.

## Use cases
- create excel files in c#
- read xlsx files in .net
- manipulate excel spreadsheets programmatically
- export data to excel from asp.net
- generate xlsx reports without excel installed
- convert data tables to excel workbooks

## When to choose
- you need a friendly high-level API for Excel files in .NET instead of raw OpenXML
- you need to read, write, or modify .xlsx/.xlsm files without Microsoft Excel installed
- you work with large spreadsheets and care about performance

## When to avoid
- you need to work with legacy .xls binary files
- you need a stable, unchanging public API - it is still evolving with migration guides between releases
- you need Excel automation like macros execution or live Excel features

## Facets
- artifact type: library
- maturity: active
- function: parser, file-system, developer-tools
- domain: files, spreadsheets, developer-tools
- platform: dotnet, cross-platform
- tags: excel, xlsx, openxml, spreadsheet, c-sharp

## Member repositories
- ClosedXML/ClosedXML (main) score 87

## Provenance
- Observed fields: from GitHub, fetched 2026-08-28T04:09:27.897836+00:00.
- Health v2: computed from the inputs above; adoption is never an input.
- Inferred fields (summary, facets, guidance): AI-extracted, prompt v1, taxonomy v1, on 2026-08-29T17:54:13.764333+00:00, confidence not recorded.
  - readme: https://github.com/ClosedXML/ClosedXML (fetched 2026-08-28T04:09:27.897836+00:00, sha ab45d3ebac23)
- Data as of 2026-08-30T08:39:29.467469+00:00.