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Simple data wrapper that attempts to wrap SheetJS libraries to provide a uniform way to access data from Excel and other spreadsheet files:

Excel files are parsed based on the content (not by filename). For example, CSV files can be renamed to .XLS and excel will do the right thing.

Supported Formats:

Format Library
XLS (BIFF5, 5.0-7.0) JS-XLS
XLS (BIFF8, 97-2003) JS-XLS
XLSX (2007+) JS-XLSX
XLSM (2007+ w/macros) JS-XLSX
XLSB (2007+ binary) JS-XLSX
XML (2003/2004) JS-XLS
DIF (plaintext) JS-HARB
SYLK (Symbolic Link) JS-HARB
ODS (OpenDocument) JS-XLSX
SocialCalc JS-HARB

Output formats:

  • XML and HTML work with Excel Web Query
  • DSV (general delimiters, including CSV and TSV)
  • JSON
  • Formulae list (e.g. A1=NOW(), A2=A1+3)
  • XLSX / XLSM work with iOS Numbers and Excel
  • Markdown tables (GFM style)
  • SocialCalc output


npm install -g j

Node Library

var J = require('j');

J.readFile(filename) opens the file specified by filename and returns an array whose first object is the parsing object (XLS or XLSX) and whose second object is the parsed file.

J.utils has various helpers that expect an array like those from readFile:

  • to_csv(w) / to_dsv(w, delim) will generate CSV/DSV respectively
  • to_json(w) will generate JSON row objects
  • to_html(w) will generate simple HTML tables
  • to_formulae(w) will generate lists of formulae
  • to_xml(w) will generate simple XML
  • to_xlsx(w) / to_xlsm(w) / to_xlsb(w) will generate XLSX/XLSM/XLSB workbooks
  • to_md(w) will generate markdown tables

CLI Tool

The node module ships with a binary j which has a help message:

$ j --help
  Usage: j [options] <file> [sheetname]
    -h, --help               output usage information
    -V, --version            output the version number
    -f, --file <file>        use specified file (- for stdin)
    -s, --sheet <sheet>      print specified sheet (default first sheet)
    -N, --sheet-index <idx>  use specified sheet index (0-based)
    -l, --list-sheets        list sheet names and exit
    -o, --output <file>      output to specified file
    -B, --xlsb               emit XLSB to <sheetname> or <file>.xlsb
    -M, --xlsm               emit XLSM to <sheetname> or <file>.xlsm
    -X, --xlsx               emit XLSX to <sheetname> or <file>.xlsx
    -S, --formulae           print formulae
    -j, --json               emit formatted JSON (all fields text)
    -J, --raw-js             emit raw JS object (raw numbers)
    -x, --xml                emit XML
    -H, --html               emit HTML
    -m, --markdown           emit markdown table (with pipes)
    -E, --socialcalc         emit socialcalc
    -F, --field-sep <sep>    CSV field separator
    -R, --row-sep <sep>      CSV row separator
    -n, --sheet-rows <num>   Number of rows to process (0=all rows)
    --dev                    development mode
    --read                   read but do not print out contents
    -q, --quiet              quiet mode


Please consult the attached LICENSE file for details. All rights not explicitly granted by the Apache 2.0 license are reserved by the Original Author. alpha

Build Status

Coverage Status

Using J for diffing XLS/XLSB/XLSM/XLSX files

Using git textconv, you can use J to generate more meaningful diffs!

One-time configuration (misc/

# Define a sheetjs diff type that uses j 
git config --global diff.sheetjs.textconv "j"
# Configure a user .gitattributes file that maps the xls{,x,m} files 
touch ~/.gitattributes
cat <<EOF >>~/.gitattributes
*.xls diff=sheetjs
*.xlsb diff=sheetjs
*.xlsm diff=sheetjs
*.xlsx diff=sheetjs
*.XLS diff=sheetjs
*.XLSB diff=sheetjs
*.XLSM diff=sheetjs
*.XLSX diff=sheetjs
# Set the .gitattributes to be used for all repos on the system: 
git config --global core.attributesfile '~/.gitattributes'

If you just want to compare formulae (for example, in a sheet using NOW):

git config --global diff.sheetjs.textconv "j -S"

NOTE: There are some known issues regarding global modules in Windows. The best bet is to npm install j in your git directory before diffing.


Segmentation faults in node v0.10.31 stem from a bug in node. J will throw an error if it is running under that version. Since versions prior to v0.10.30 do not exhibit the problem, rolling back to a previous version of node is the best remedy. See for more information.