What Is Open My Files?

Updated

Open My Files (openmyfiles.com) is a file information directory: a reference site that organizes pages by file format category so you can look up what a given file extension or format is. It is useful when you encounter an unfamiliar extension and want a general explanation of the format, not when you need to open, convert, or repair a specific file.

What the site provides

The homepage presents itself as "The #1 File Information Directory" and offers two main ways to navigate:

  • A search box ("Search for:") for looking up a file format directly.
  • Category listings under "Top File Format Categories," each grouping related extensions.

The categories visible on the homepage, with example entries, are:

Category Example formats listed
Archive DESKTOP, IES, ISO, ZIP
Audio Files M4P, PCM, COPY, DSF, AU
Data ODP, XML
Raster Image Files ITHMB, DPX, MAC, EXR, SCP
Spreadsheet Files XLR, XLS, XLSB, XLSM, XLSX
Executable Files XLM, AHK, ACTION, JSF, SCRIPT
Vector Image Files POSTSCRIPT, DRAWING, IDEA, PUPPET, PFD
Video Files OGV, VID, H264, QT, 264

Each category page ("More") presumably expands the list of formats in that group.

How to use it

  1. If you know the extension, type it into the search field on the homepage and submit. The expected result is a page describing that format.
  2. If you only know the general kind of file (e.g., it's a video or a spreadsheet), open the matching category and scan the list for your extension.
  3. Read the format entry to understand what the extension represents and which category it belongs to.

A practical example: you receive a file ending in .dsf and don't recognize it. Searching "DSF" or browsing the Audio Files category tells you it is treated as an audio format here, which is enough to decide whether to keep, open, or ask the sender about it.

What to keep in mind

  • The site is a directory of format information, not a file-opening or conversion tool. Nothing on the homepage indicates it processes your files.
  • The category assignments reflect how this directory organizes formats; some entries are unusual (e.g., COPY under Audio, XLM under Executable), so treat the grouping as a finding aid rather than an authoritative taxonomy.
  • No pricing or account information appears on the homepage, so there is no stated basis to assume paid tiers or login requirements either way.

If your goal is simply "what is this extension?", start with the search box. If your goal is to actually open or convert a file, this site is a starting reference, not the tool you need.