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[ExceLint logo]

ExceLint is an Excel add-in that automatically finds formula errors in spreadsheets. It is a product of research from the PLASMA lab @ UMass Amherst and Microsoft Research.

by Dan Barowy (Williams College), Emery Berger (UMass Amherst / Microsoft Research), and Ben Zorn (Microsoft Research).

Talks on ExceLint


ExceLint works as an add-in for all modern versions of Excel, including Mac, Windows, and online. You need to install the file manifest.xml following the appropriate instructions for each platform:

Source code

Source code for the add-in may be found at its GitHub repository.


The ExceLint add-in does not collect personally identifiable information. See the privacy statement for more details.


ExceLint is provided without any guarantee of support. However, we welcome bug reports and enhancement/feature requests.

Technical Details

The following technical paper describes how ExceLint works and includes an extensive empirical evaluation: ExceLint: Automatically Finding Spreadsheet Formula Errors, Daniel W. Barowy (Williams College), Emery D. Berger (University of Massachusetts Amherst), Benjamin Zorn (Microsoft Research). In Proceedings of the ACM on Programming Languages, Volume 2, Number OOPSLA.


The ExceLint addin is written entirely in TypeScript. It is already set up to be hostable locally.


To run ExceLint locally, you will first need to install Node and Git.

Running the ExceLint service locally

First, run the following commands to build and start the local ExceLint service (which just hosts the assets).

git clone
cd ExceLint-addin
export NODE_OPTIONS=--no-experimental-fetch
npm install
npm run start-local


The easiest way to test the local service is to use Excel 365 ( Open a workbook, click the Insert menu, then click "Office Add-ins" on the ribbon. Click "Upload My Add-in" (in the upper-right hand corner), and select the file manifest-localhost.xml. If everything works as planned, you should see an icon for ExceLint on the Home ribbon. Click on it and it should open the task pane on the right-hand side of the window.


This material is based upon work supported by the National Science Foundation under Grant No. CCF-1617892. Any opinions, findings, and conclusions or recommendations expressed in this material are those of the author(s) and do not necessarily reflect the views of the National Science Foundation.