FID File

What are FID files and how to open them

Are you having problems opening a FID file or just wondering what they contain? We explain what these files are used for and show you software that we know can open or otherwise handle your files.

What is a FID file?

FID files have multiple uses, and Windows Indexing Service Index is one of them. Read more about the other uses further down the page.

Windows Indexing Service Index File

Files that contain the .fid file extension are most commonly associated with the Microsoft Windows Indexing Service. These FID files contain index files that the Windows indexing utility has created. The indexes contained in these files help the operating system perform search functions more efficiently.

How to open FID files

Important: Different programs may use files with the FID file extension for different purposes, so unless you are sure which format your FID file is, you may need to try a few different programs.

While we have not verified the apps ourselves yet, our users have suggested five different FID openers which you will find listed below.

Last updated: December 21, 2022

All known file formats using extension .FID

While Windows Indexing Service Index File is a popular type of FID-file, we know of 3 different uses of the .FID file extension. Different software may use files with the same extension for different types of data.

Felix Format Spectra Data File

Felix is the industry standard software program for off-line data processing, spectral visualization, and analysis of high resolution, one- to four-dimensional, homonuclear and heteronuclear NMR data.

FID opener for Windows

We have identified one FID opener that is compatible with this specific type of FID file.


More file formats using the FID extension

Through our research of FID files, we know that the following formats exist. However, we have not yet analyzed them in detail.

  • Acorn NMR NUTs Format Spectra Data File

Various apps that use files with this extension

These apps are known to open certain types of FID files. Remember, different programs may use FID files for different purposes, so you may need to try out a few of them to be able to open your specific file.

GOM PlayerGOM PlayerUser submitted
KMPlayerKMPlayerUser submitted
RealPlayerRealPlayerUser submitted
WUFI AnimationWUFI AnimationUser submitted
flexAnalysisflexAnalysisUser submitted

Help us help others helps thousands of users every day, and we would love to hear from you if you have additional information about FID file formats, example files, or compatible programs. Please use the links below or email us at to discuss further.