OpenAPI for Excel

Latest release: Version 1.0.0 (re-released December 19, 2018)

Verify which version of Excel is running on your machine before downloading the add-in. See the Support page for more information.

OpenAPI for Excel (32-bit)

OpenAPI for Excel (64-bit)

For more information about this release, please see Add-in Release Notes.

The certificate used to sign the August 8, 2018 version of the OpenAPI for Excel add-in has expired as of December 19, 2018. Users are advised to update to the latest version as soon as possible to prevent errors from the Microsoft Excel Trust Center.


Version 1.0.0 supports Windows only and requires the following software:


The OpenAPI for Excel add-in behaves as any other add-in and can be installed in two ways, either for one-time use or as persistent installation.

One-time use

Using the add-in by opening the .xll-file with Excel ensures no changes are saved to Excel's add-in settings. This is useful for testing purposes or when you're looking to experiment with the add-in for the first time, such as in the Get Started in 5 Minutes or Less guide. This procedure does not affect functionality and removes any and all traces after Excel is closed. Make sure to load the add-in first if it is not installed persistently when opening Excel spreadsheets that use OpenAPI for Excel formulas. If the spreadsheets display numerous #NAME? errors, this is likely caused by a missing add-in, as Excel cannot find the formulas referenced in each of the affected cells.

Persistent installation

Loading the add-in automatically each time Excel is launched can be achieved by adding the .xll file to Excel's add-in list under settings:

  1. Save the .xll-file in a (permanent) location. The downloads folder is not recommended. If the file is removed, the add-in will fail to load and Excel will throw errors every time it is launched.
  2. Open Options in Excel and navigate to the Add-ins section.
  3. Click Go... at the bottom of the page to manage Excel add-ins.
  4. Click Browse and navigate to the location where the .xll-file is stored.
  5. Select the file and make sure the OpenAPI for Excel  Add-in is ticked in the Add-ins screen.
  6. If prompted, confirm to copy the add-in file to the Addins folder.
  7. Click OK. The Open Api tab now appears in Excel and is ready for use every time Excel is launched.

Updating to a newer version of the OpenAPI for Excel add-in requires removal of the old add-in from the settings menu before the newer version is added to prevent conflicts. Please make sure the default add-ins folder does not contain any OpenAPI for Excel add-ins before loading a newer version. The usual location of the add-in folder is: C:\Users\UserName\AppData\Roaming\Microsoft\AddIns. Also check whether any COM add-ins remain in the add-ins menu. These should be removed as well.

Version 1.0.0 (August 8, 2018)

OpenAPI for Excel (32-bit)

OpenAPI for Excel (64-bit)