# Read-only files

If a file is read-only, it is marked with the closed lock icon ![the Locked icon](https://resources.jetbrains.com.cn/help/img/idea/2026.2/app.expui.general.locked.svg) in the [status bar](guided-tour-around-the-user-interface.html#read_only_widget). If a file is writable, it is marked with the open lock icon ![the Unlocked icon](https://resources.jetbrains.com.cn/help/img/idea/2026.2/app-client.expui.general.unlocked.svg).

Procedure: Toggle read-only mode on and off

* Open a file in the editor and click the lock icon ![the Locked icon](https://resources.jetbrains.com.cn/help/img/idea/2026.2/app.expui.general.locked.svg) / ![the Unlocked icon](https://resources.jetbrains.com.cn/help/img/idea/2026.2/app-client.expui.general.unlocked.svg) in the [status bar](guided-tour-around-the-user-interface.html#status-bar).

* Alternatively, select a file in the Project tool window (`Alt+1` (Windows), `⌘ 1` (macOS), `⌘ 1` (IntelliJ IDEA Classic (macOS)), `⌘ 1` (macOS System Shortcuts), `Alt+1` (XWin), `Alt+1` (GNOME), `Alt+1` (KDE), `Alt+1` (Emacs), `Alt+1` (Sublime Text), `⌘ 1` (Sublime Text (macOS)), `Ctrl+1` (NetBeans), `Ctrl+Alt+L` (Visual Studio), `⌘ ⌥ L` (Visual Studio (macOS)), `Alt+1` (Eclipse), `Alt+1` (Eclipse (macOS))), go to `File | File Properties` in the main menu and click Make file read-only.

![Making file read-only](https://resources.jetbrains.com.cn/help/img/idea/2026.2/file_readonly.png)

Files can be read-only in certain cases. In these cases, clicking the ![the Locked icon](https://resources.jetbrains.com.cn/help/img/idea/2026.2/app.expui.general.locked.svg) / ![the Unlocked icon](https://resources.jetbrains.com.cn/help/img/idea/2026.2/app-client.expui.general.unlocked.svg) icon the status bar will not make the file writable.

* The file is a [decompiled class](decompiler.html). Complied classes are normally read-only in IntelliJ IDEA.

* The read-only status is set by a version control system. For example, the file can be [locked](null) by Subversion. In this case, use IntelliJ IDEA version control integration features to make the file writable.

* The file size exceeds 2.5 MB. Such files are considered too large for editing.

* Library files in IntelliJ IDEA are normally read-only by default as the code from them should be used as is. For such files, you will not see the lock icon in the status bar. IntelliJ IDEA applies [Reader mode](reader-mode.html) to library files by default.

* The file does not belong to the project. In this case, the [Non-Project Files Protection](non-project-files-access-dialog.html) dialog appears, prompting you to select an action.

* The file belongs to the generated sources ![](https://resources.jetbrains.com.cn/help/img/idea/2026.2/app-client.expui.nodes.generatedSource.svg) or generated test sources ![](https://resources.jetbrains.com.cn/help/img/idea/2026.2/app-client.expui.nodes.generatedTestRoot.svg) root. Files in these folders are usually read-only as they are generated automatically rather than written manually and can be regenerated. Learn more about different types of folders from [Content roots](content-roots.html).

* The file may be marked as read-only in your operating system. To check this status, you can inspect file attributes on Windows or permissions on Unix-based systems like Linux or macOS.

## See also

### Related

[Reader mode](reader-mode.html)