5xx Server ErrorRFC 9110
501Not Implemented
Server does not support the functionality required.
What it means
The server does not support the functionality required to fulfill the request. This is the appropriate response when the server does not recognize the request method and is not capable of supporting it for any resource.
When to use it
- ✓HTTP method is not implemented by the server
- ✓Feature is planned but not yet built
- ✓Placeholder for future functionality
Code Examples
Express — placeholder route
javascript
app.patch('/users/:id', (req, res) => {
res.status(501).json({
error: 'Not Implemented',
message: 'PATCH support coming in v2',
});
});