Here is what clangd can do for you. Screenshots show VSCode; the available features and UI will depend on your editor.


Errors and warnings

clangd runs the clang compiler on your code as you type, and shows diagnostics of errors and warnings in-place.

screenshot: clang errors

(Some errors are suppressed: diagnostics that require expanding templates in headers are disabled for performance reasons).


The compiler can suggest fixes for many common problems automatically, and clangd can update the code for you.

screenshot: apply fix

If a missing symbol was seen in a file you’ve edited recently, clangd will suggest inserting it.

screenshot: include-fixer fix

clang-tidy checks

clangd embeds clang-tidy which provides extra hints about code problems: bug-prone patterns, performance traps, and style issues.

screenshot: apply clang-tidy fix

clangd respects your project’s .clang-tidy file which controls the checks to run. Not all checks work within clangd.

Code completion

You’ll see suggestions as you type based on what methods, variables, etc are available in this context.

screenshot: code completion

Abbreviating words may help you find the right result faster. If you type in camelCase but the function you’re looking for is snake_case, that’s OK.

Namespace and include insertion

clangd will sometimes suggest results from other files and namespaces. In this case the correct qualifier and #include directive will be inserted.

screenshot: code completion insert ns

Signature help

Some editors will show you the parameters of the function you’re calling, as you fill them in.

screenshot: signature help


These features let you navigate your codebase.

They work across the files you’ve opened.

clangd will also automatically index your whole project.

Find definition/declaration

Jump to the definition or declaration of a symbol under the cursor.

screenshot: go to def

(Some editors only expose “find definition” - hit it again to jump to the declaration).

This also works on #include lines, to jump to the included file.

Find references

Show all references to a symbol under the cursor.

screenshot: find references

Some editors will automatically highlight local references to the selected symbol as you move around a file.

clangd informs the editor of the code structure in the current file. Some editors use this to present an outline view:

screenshot: outline

In VSCode, this also allows jumping to a symbol within the current file.

Searching for symbols within the scope of the whole project is also possible.

screenshot: navigation


Hover over a symbol to see more information about it, such as its type, documentation, and definition.

screenshot: hover

Hovering over auto will show the underlying type.


clangd embeds clang-format, which can reformat your code: fixing indentation, breaking lines, and reflowing comments.

screenshot: format selection

clangd respects your project’s .clang-format file which controls styling options.

Format-as-you-type is experimental and doesn’t work well yet.



Rename a symbol under the cursor. All usages of the symbol will be renamed, including declaration, definition and references.

screenshot: rename

Most symbols are renameable, such as classes, variables, functions and methods.

Renaming a symbol will affect usages of the name across the project.

Known limitations

TIP: the rename workflow highly depends on the editor you are using. Some editors, e.g. VSCode, provide a way to preview the rename changes before applying them; while some just apply the changes directly.

Semantic Highlighting

clangd computes semantic highlight tokens to enhance the source code theming.

screenshot: highlight

A token may be associated with one highlight kind and multiple highlight modifiers, as defined by the following section.


clangd supports following standard LSP token kinds:

Kind LSP Name Since Version Note
Variable variable 9  
LocalVariable variable 9  
StaticField variable 9  
Parameter parameter 9  
StaticMethod function 9  
Function function 9  
Method method 9  
Field property 9  
Class class 9  
Interface interface 12 Objective-C only
Enum enum 9  
EnumConstant enumMember 9  
Type type 12  
Typedef type 9  
Primitive type 9  
TemplateParameter typeParameter 9  
Namespace namespace 9  
Macro macro 9  
Modifier modifier 16 override/final
Operator operator 15 Including new/delete
Bracket bracket 15 All ()[]{}
Label label 15  
InactiveCode comment 11 Inactive preprocessor branches

On top of that, as an extension, clangd supports following additional token kinds:

Kind LSP Name Since Version Note
Unknown unknown 12 Dependent names
Concept concept 12  


clangd supports following standard LSP token modifiers:

Modifier LSP Name Since Version Note
Declaration declaration 12  
Definition definition 16  
Deprecated deprecated 12  
Readonly readonly 12  
Static static 12  
Abstract abstract 12 For abstract methods
DefaultLibrary defaultLibrary 13 From standard library

On top of that, as an extension, clangd supports following additional token modifiers:

Modifier LSP Name Since Version Note
Deduced deduced 12 For auto
Virtual virtual 13  
DependentName dependentName 12  
UsedAsMutableReference usedAsMutableReference 14 Mutable reference argument
UsedAsMutablePointer usedAsMutablePointer 15 Mutable pointer argument
ConstructorOrDestructor constructorOrDestructor 15 ctor/dtor name
UserDefined userDefined 15  
FunctionScope functionScope 12  
ClassScope classScope 12  
FileScope fileScope 12  
GlobalScope globalScope 12