How to Fix Error Squiggles Not Showing in VS Code?

The Error Squiggles (the red or green wavy underlines) in VS Code show that there are syntax or semantic issues in your code. These squiggles work through IntelliSense and specific language extensions. If the required extension is missing or fails to load, the squiggles either stop working or don’t appear at all.

In this guide, you’ll learn several reliable methods to enable and fix Error Squiggles in Visual Studio Code so your editor can highlight problems accurately and in real time.

1. Restart VS Code

Restarting VS Code can often fix this issue quickly. A fresh launch clears temporary glitches, reloads all active extensions, and reapplies settings. If the squiggles didn’t load correctly during the first launch, restarting helps initialize them properly.

2. Check if You Have the Extension

Error squiggles depend on the correct language extension. For example, if you’re writing Python code without the Python extension installed, VS Code won’t be able to detect or highlight issues. Without the right extension, the editor can’t understand your code or generate squiggles.

1. Open VS Code and go to the Extensions tab by clicking the icon or pressing CTRL + SHIFT + X.
2. Search for the language you’re currently using.
3. Check whether the extension is installed.

3. Enable Error Squiggles in Settings

If error squiggles are turned off in your settings, the editor won’t underline any problems. Turning this option on ensures that errors are displayed as soon as they are detected.

1. Press CTRL + , to open Settings.
2. Search for error squiggles in the search bar.
3. Set the C_Cpp: Error Squiggles option to enabled or enabledIfIncludesResolve.
4. Restart VS Code to apply the change.

4. Enable Using settings.json

Sometimes, UI-based settings don’t apply properly because of workspace overrides or user-level configurations. Editing the settings.json file directly applies the correct value at the core configuration level.

1. Press CTRL + SHIFT + P to open the Command Palette.
2. Type Preferences: Open User Settings (JSON) and select it.
3. Search for “C_Cpp.errorSquiggles” inside the file.
4. Make sure the value is set to “Enabled”.
5. If it’s missing, insert the following code:

   { "files.autoSave": "afterDelay", "editor.quickSuggestions": { "other": true, "comments": true, "strings": true }, "javascript.validate.enable": true, "typescript.validate.enable": true }

   

6. Press CTRL + S to save and restart VS Code.