How do I open a .bak file?

Copy it, rename the copy back to the original extension (e.g. .docx or .dwg), and open it in the matching program.

Can I just delete .bak files?

Yes, if you don't need the earlier version — they are backups of old data.

Which programs create .bak files?

Many — Microsoft Word, AutoCAD, database tools, game and app config editors all use .bak for backups.

How do I know what program made a .bak?

Use `file name.bak` on macOS/Linux, or check which app's folder it lives in — Word, AutoCAD and database tools all create .bak files.

What Is a .BAK File?

You found a .bak file next to your document. It is a backup copy. Here is how to open it, restore from it, or safely remove it.

What a .bak file is

A .bak file is a backup copy that a program saved before overwriting the original — Word, AutoCAD, game configs, database tools and many editors do this. It usually contains the previous version of your file.

How to open it

A .bak is just the original file with a different extension. To open it, make a copy and rename it back to the real extension — e.g. report.docx.bak → report-old.docx — then open it in the matching program.

How to restore from it

If your current file is corrupted or lost, rename the .bak to the original name (keep a copy first) and open it to recover the earlier version.

Is it safe to delete?

Yes, if you are happy with the current file and don't need the previous version. It only holds old data.

How to open a .bak file by OS

Windows: copy the file, then in File Explorer enable View → File name extensions and rename the copy back to the real extension (e.g. .docx, .dwg, .sql); open it in the matching program.

macOS: duplicate the file (⌘D), rename the copy's extension in Finder, then open in the app that made it.

Linux: run file report.docx.bak to confirm the real type, copy and rename, then open in the right app.

Common problems

If you don't know which program made the .bak, the file command (Linux/macOS) or a hex viewer reveals the format signature. Never rename the original — always work on a copy so you can retry.