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", 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"); // Remove logging from final output console.log(new Map(newResponse.headers)) return newResponse; },
};
export default { async fetch(request) { 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;
You can also use the custom-headers-example
template to deploy this code to your custom domain.