What is this file? Paste the name and find out

The odd files that appear on your computer — .aae, .crdownload, .part, .dat, .tmp — each get a plain-English page here: what it is, whether it is safe to delete, and what opens it. The identifier below matches the extension in your browser; nothing is uploaded.

File guides

• What Is an .ASD File? — An .asd file is Microsoft Word's AutoRecover save. Here is how to recover your document from it and where Word keeps them.
• What Is a .BAK File? — A .bak file is a backup copy an app made before changing the original. Here is how to open it, restore it, or safely delete it.
• What Is a .CHK File? — A .chk file is a fragment CHKDSK recovered from a damaged disk. Here is how to identify what it was and whether you can restore it.
• What Is a CRDOWNLOAD File? — A .crdownload file is a download Chrome hasn't finished yet. Here is how to complete it, resume it, or safely delete a stuck one.
• What Is a DAT File? — A .dat file is generic data — its format depends entirely on the program that made it. Here is how to figure out what yours is, including the winmail.dat email case.
• What Is a .DOWNLOAD File? — A .download file is a download Safari hasn't finished. Here is how to resume it, complete it, or safely delete one that is stuck.
• What Is a .DS_STORE File? — A .DS_Store file is a hidden macOS file that stores folder view settings. Here is why it appears on other systems and how to remove it.
• What Is a .GID File? — A .gid file is an old Windows Help index/settings file. Here is what created it and whether you can safely delete it.
• What Is an .INI File? — An .ini file is a plain-text configuration file that stores program settings. Here is how to open and edit one, and what desktop.ini does.
• What Is a .LNK File? — A .lnk file is a Windows shortcut pointing to another file. Here is what it does, why one may show as broken, and when it is a security risk.
• What Is a .NOMEDIA File? — A .nomedia file tells Android to skip a folder when scanning for photos, music and video. Here is how to add or remove one.
• What Is a PART File? — A .part file is an incomplete download, usually from Firefox or a download manager. Here is how to complete it or safely delete a stuck one.
• What Is a .PARTIAL File? — A .partial file is a download your browser hasn't finished yet. Here is how to resume it, complete it, or safely delete a stuck one.
• What Is a .SWP File? — A .swp file is Vim's swap file for recovering unsaved edits. Here is how to recover your work and safely delete a leftover one.
• What Is Thumbs.db? — Thumbs.db is a hidden Windows file caching folder thumbnails. Here is what it does, why it locks, and how to disable or delete it.
• What Is a .CRSWAP File? — A .crswap file is a temporary scratch file written by Chrome or ChromeOS during a save. Here is what it is and whether you can delete it.
• What Is a TMP File? — A .tmp file is a temporary scratch file left by a program. Here is what makes them, whether they are safe to delete, and how to clean them up.