What is a .ini file?
Initialization / Configuration File · Code and data · Microsoft (popularized in early Windows) · 1980s
An INI file is a simple text file that stores a program's settings as key=value pairs grouped under [sections]. Programs read it at startup to remember your options, and you can edit it in any text editor.
What is a .ini file used for?
The format is deliberately plain: lines like key=value, grouped under headings in square brackets, with a semicolon starting a comment. That simplicity is why it has stayed in use for decades.
INI files came from early Windows but are still everywhere, from games to desktop apps, whenever a program needs a small, human-editable settings file.
You can change settings by editing the file directly, which is handy when an app has no option for something in its menus. Back the file up first, because a wrong value can misconfigure the program.
It is plain text, so it cannot run and is safe to open. The only risk is breaking a setting, which you fix by restoring your backup.
What opens a .ini file?
The .ini format opens in the following apps, grouped by operating system. If one app does not work, try another from the same list.
Windows
- Notepad
- Notepad++
- VS Code
macOS
- TextEdit
- VS Code
Linux
- Any text editor
Web
- Any online text viewer
Open a .ini file step by step
- Confirm the file really is a .ini. Drop it into the WhatFileType identifier, which reads its signature in your browser without uploading anything.
- On Windows, open it with Notepad or Notepad++.
- On Mac, use TextEdit or VS Code.
- On Linux, try Any text editor.
- Still stuck? Convert the .ini to Already plain text, which opens more widely.
Why can't I open my .ini file?
Almost always because no installed app understands INI. Install one of the apps above, or convert the file to a format your existing software already reads. If double-clicking opens the wrong program instead of nothing at all, the file association is set to the wrong app rather than the file being broken.
The other possibility is that the file is not really a .ini at all. Drop it into the file identifier to check it by its bytes instead of its name. Nothing is uploaded.
How to convert a .ini file
You can convert a .ini file to Already plain text using a conversion tool or the export menu of an app that opens it.
INI has no fixed magic number, so there is no signature table on this page. Its bytes alone do not prove the format: identification relies on the extension, the structure of the content and the program that created it. The magic-numbers reference lists the formats that do carry one.
Frequently asked questions
What is a .ini file?
An INI file is a simple text file that stores a program's settings as key=value pairs grouped under [sections]. Programs read it at startup to remember your options, and you can edit it in any text editor.
How do I edit an INI file?
Open it in a plain-text editor such as Notepad or VS Code, change the value after the equals sign, and save. Make a backup copy first so you can undo a mistake.
Is it safe to edit an INI file?
Yes, the file itself is harmless text. The only risk is setting a wrong value and confusing the program, which you can undo by restoring your backup.
Related formats
Sources
Details on this page were checked against authoritative references. How sources are ranked and what is deliberately left out is set out in the methodology.