Alter headers
Example of how to add, change, or delete headers sent in a request or returned in a response.
Run Workerexport default { async fetch(request) { const response = await fetch("https://example.com");
// Clone the response so that it's no longer immutable const newResponse = new Response(response.body, response);
// Add a custom header with a value newResponse.headers.append( "x-workers-hello", "Hello from Cloudflare Workers" );
// Delete headers newResponse.headers.delete("x-header-to-delete"); newResponse.headers.delete("x-header2-to-delete");
// Adjust the value for an existing header newResponse.headers.set("x-header-to-change", "NewValue");
return newResponse; },
};
export default { async fetch(request): Promise<Response> { const response = await fetch(request);
// Clone the response so that it's no longer immutable const newResponse = new Response(response.body, response);
// Add a custom header with a value newResponse.headers.append( "x-workers-hello", "Hello from Cloudflare Workers" );
// Delete headers newResponse.headers.delete("x-header-to-delete"); newResponse.headers.delete("x-header2-to-delete");
// Adjust the value for an existing header newResponse.headers.set("x-header-to-change", "NewValue");
return newResponse; },
} satisfies ExportedHandler;
from js import Response, fetch
async def on_fetch(request): response = await fetch("https://example.com")
# Clone the response so that it's no longer immutable new_response = Response.new(response.body, response)
# Add a custom header with a value new_response.headers.append( "x-workers-hello", "Hello from Cloudflare Workers" )
# Delete headers new_response.headers.delete("x-header-to-delete") new_response.headers.delete("x-header2-to-delete")
# Adjust the value for an existing header new_response.headers.set("x-header-to-change", "NewValue")
return new_response
You can also use the custom-headers-example
template to deploy this code to your custom domain.