# Quick documentation

> **TL;DR**
> Available for: C/C++, Rust, other [supported languages](clion-features-in-different-languages.html), and [CMake scripts](cmakelists-txt-file.html).
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> Invoke: on hover or `Ctrl+Q` (Windows), `F1` (macOS), `⌃ J` (IntelliJ IDEA Classic (macOS)), `⌘ I` (macOS System Shortcuts), `Ctrl+Q` (XWin), `Ctrl+Q` (GNOME), `Ctrl+Q` (KDE), `Ctrl+Q` (Emacs), `Ctrl+Q` (Sublime Text), `Ctrl+Q` (Sublime Text (macOS)), `⌘ ⌃ ⇧ /` (Xcode), `Ctrl+K, I` (Visual Studio), `⌘ K, I` (Visual Studio (macOS)), `Ctrl+Q` (ReSharper), `⌃ Q` (ReSharper (macOS)), `Ctrl+Q` (QtCreator), `Ctrl+Q` (QtCreator (macOS)), `Ctrl+Q` (NetBeans), `Alt+Middle-Click` (Eclipse), `⌥ Middle-Click` (Eclipse (macOS))

Quick Documentation popup helps you get more information on a code element at caret. CLion shows quick documentation in a popup on mouseover automatically. Depending on the element you invoke it for, the popup can include:

* Function signature details and code documentation (either regular or [Doxygen](creating-and-viewing-doxygen-documentation.html) comments): ![Function signature details with Doxygen comments](https://resources.jetbrains.com/help/img/idea/2026.2/cl_quickdoc_func_doxygen.png)

* Inferred types: ![C++ inferred type in Quick Documentation popup](https://resources.jetbrains.com/help/img/idea/2026.2/cl_qdoc_inferredtype.png)

* Copy/move details for structs and classes. In the example below, you can also refer to the [TODO comments](using-todo.html) included in the popup: ![Copyability/movability of a struct/class](https://resources.jetbrains.com/help/img/idea/2026.2/cl_quickdoc_movecopy.png)

* For a standard function, structure, or another item, the popup also includes a link to its cppreference: ![The link to external documentation](https://resources.jetbrains.com/help/img/idea/2026.2/cl_external_doc_link.png)

* Macro replacements to help you better understand and debug nested macros (like [Boost.Test](boost-test-support.html) or [Catch](catch-tests-support.html) macros). In the popup, you will see the final macro replacement properly formatted, with highlighted strings and keywords: ![Formatted macro expansion in Quick Documentation popup](https://resources.jetbrains.com/help/img/idea/2026.2/cl_qdoc_format.png)

* Value and size of a constant expression evaluated at compile time: ![Values of constant expressions](https://resources.jetbrains.com/help/img/idea/2026.2/cl_values_of_constant_expressions.png) Compile-time evaluation is especially helpful for working with `constexpr` and `consteval` calculations and in template metaprogramming: ![Evaluated values](https://resources.jetbrains.com/help/img/idea/2026.2/cl_evaluated_values_templates.png)

* Enumeration values as integer: ![Enum values](https://resources.jetbrains.com/help/img/idea/2026.2/cl_enum_values.png)

* CMake code elements In [CMake scripts](cmakelists-txt-file.html), CLion shows documentation for variables, commands, properties, modules, and policies. For example, you can view quick documentation for completion suggestions in `find_package`: ![Quick doc in CMake completion](https://resources.jetbrains.com/help/img/idea/2026.2/cl_cmake_quickdoc_completion.png) > **Tip:** > Find out more in [Code insight for CMake](cmakelists-txt-file.html#code-insight-cmake).

Procedure: The popup menu

* Click ![](https://resources.jetbrains.com/help/img/idea/2026.2/app.actions.more.svg) in the popup to change the font size, display the quick documentation toolbar, or go to the source code:

![Jump to Source in the documentation popup](https://resources.jetbrains.com/help/img/idea/2026.2/cl_quickdoc_jumptosource.png)

Procedure: View documentation in the tool window

With the default settings, pressing `Ctrl+Q` (Windows), `F1` (macOS), `⌃ J` (IntelliJ IDEA Classic (macOS)), `⌘ I` (macOS System Shortcuts), `Ctrl+Q` (XWin), `Ctrl+Q` (GNOME), `Ctrl+Q` (KDE), `Ctrl+Q` (Emacs), `Ctrl+Q` (Sublime Text), `Ctrl+Q` (Sublime Text (macOS)), `⌘ ⌃ ⇧ /` (Xcode), `Ctrl+K, I` (Visual Studio), `⌘ K, I` (Visual Studio (macOS)), `Ctrl+Q` (ReSharper), `⌃ Q` (ReSharper (macOS)), `Ctrl+Q` (QtCreator), `Ctrl+Q` (QtCreator (macOS)), `Ctrl+Q` (NetBeans), `Alt+Middle-Click` (Eclipse), `⌥ Middle-Click` (Eclipse (macOS)) (`View | Quick Documentation`) opens quick documentation in a popup. You can change the settings to view documentation in the tool window.

* In the quick documentation popup, click ![the Show Options Menu icon](https://resources.jetbrains.com/help/img/idea/2026.2/app.actions.more.svg) and disable the Show Documentation Popup First option.

* In the Documentation tool window, click the ![Show Options Menu](https://resources.jetbrains.com/help/img/idea/2026.2/app.expui.general.settings.svg) icon on the tool window toolbar and disable the Show Documentation Popup First option.

Procedure: Keep documentation in the tool window

You can open a piece of documentation for a specific code element in the tool window and keep viewing documentation for other elements in your current file.

1. Place the caret at the required code element and press `Ctrl+Q` (Windows), `F1` (macOS), `⌃ J` (IntelliJ IDEA Classic (macOS)), `⌘ I` (macOS System Shortcuts), `Ctrl+Q` (XWin), `Ctrl+Q` (GNOME), `Ctrl+Q` (KDE), `Ctrl+Q` (Emacs), `Ctrl+Q` (Sublime Text), `Ctrl+Q` (Sublime Text (macOS)), `⌘ ⌃ ⇧ /` (Xcode), `Ctrl+K, I` (Visual Studio), `⌘ K, I` (Visual Studio (macOS)), `Ctrl+Q` (ReSharper), `⌃ Q` (ReSharper (macOS)), `Ctrl+Q` (QtCreator), `Ctrl+Q` (QtCreator (macOS)), `Ctrl+Q` (NetBeans), `Alt+Middle-Click` (Eclipse), `⌥ Middle-Click` (Eclipse (macOS)). If the popup appears, press `Ctrl+Q` (Windows), `F1` (macOS), `⌃ J` (IntelliJ IDEA Classic (macOS)), `⌘ I` (macOS System Shortcuts), `Ctrl+Q` (XWin), `Ctrl+Q` (GNOME), `Ctrl+Q` (KDE), `Ctrl+Q` (Emacs), `Ctrl+Q` (Sublime Text), `Ctrl+Q` (Sublime Text (macOS)), `⌘ ⌃ ⇧ /` (Xcode), `Ctrl+K, I` (Visual Studio), `⌘ K, I` (Visual Studio (macOS)), `Ctrl+Q` (ReSharper), `⌃ Q` (ReSharper (macOS)), `Ctrl+Q` (QtCreator), `Ctrl+Q` (QtCreator (macOS)), `Ctrl+Q` (NetBeans), `Alt+Middle-Click` (Eclipse), `⌥ Middle-Click` (Eclipse (macOS)) again to switch to the tool window.

The asterisk symbol (`*`) on the documentation tab means that the tab is not pinned, so its content will be replaced by documentation for another code element that you select in the editor.

2. Right-click the tab with the documentation in the documentation tool window and enable the Keep This Documentation option.

After that, the current documentation tab will be pinned. You can return to the editor and view documentation for other code elements that will open either in the popup or in a new tab in the tool window.

![Keep Quick Documentation in tool window](https://resources.jetbrains.com/help/img/idea/2026.2/cl_keep-quick-documentation.png)

Procedure: Specify the popup delay

* To specify the delay in milliseconds after which the popup should appear, go to `Settings | Editor | Code Editing | Editor Tooltips` and enter the necessary value in the Tooltip delay field.

Procedure: Disable quick doc on mouseover

* In the Settings dialog (`Ctrl+Alt+S` (Windows), `⌘ Comma` (macOS), `⌘ Comma` (IntelliJ IDEA Classic (macOS)), `⌘ Comma` (macOS System Shortcuts), `Ctrl+Alt+S` (XWin), `Ctrl+Alt+S` (GNOME), `Ctrl+Alt+S` (KDE), `Ctrl+Alt+S` (Emacs), `Ctrl+Alt+S` (Sublime Text), `⌘ Comma` (Sublime Text (macOS)), `⌘ Comma` (Xcode), `Ctrl+Alt+S` (Visual Studio), `⌘ Comma` (Visual Studio (macOS)), `Ctrl+Alt+S` (ReSharper), `⌘ Comma` (ReSharper (macOS)), `Ctrl+Alt+S` (QtCreator), `⌘ Comma` (QtCreator (macOS)), `Ctrl+Alt+S` (NetBeans), `Ctrl+Alt+S` (Eclipse), `⌘ Comma` (Eclipse (macOS))), go to `Editor | Code Editing | Quick Documentation` and clear the Show quick documentation on hover checkbox.

You can also click ![](https://resources.jetbrains.com/help/img/idea/2026.2/app.actions.more.svg) in the popup and disable the Show on Mouse Move option.

In this case, to view documentation for a symbol at caret, press `Ctrl+Q` (Windows), `F1` (macOS), `⌃ J` (IntelliJ IDEA Classic (macOS)), `⌘ I` (macOS System Shortcuts), `Ctrl+Q` (XWin), `Ctrl+Q` (GNOME), `Ctrl+Q` (KDE), `Ctrl+Q` (Emacs), `Ctrl+Q` (Sublime Text), `Ctrl+Q` (Sublime Text (macOS)), `⌘ ⌃ ⇧ /` (Xcode), `Ctrl+K, I` (Visual Studio), `⌘ K, I` (Visual Studio (macOS)), `Ctrl+Q` (ReSharper), `⌃ Q` (ReSharper (macOS)), `Ctrl+Q` (QtCreator), `Ctrl+Q` (QtCreator (macOS)), `Ctrl+Q` (NetBeans), `Alt+Middle-Click` (Eclipse), `⌥ Middle-Click` (Eclipse (macOS)) or click `View | Quick Documentation` from the main menu.

## See also

### How tos

[Doxygen documentation](creating-and-viewing-doxygen-documentation.html) [TODO comments](using-todo.html)

### Concepts

[CMakeLists.txt](cmakelists-txt-file.html)

### Procedures

[Unit testing tutorial](unit-testing-tutorial.html)