Use GetBucketWebsite with an Amazon SDK or CLI

                // Get the website configuration.
                GetBucketWebsiteRequest getRequest = new GetBucketWebsiteRequest()
                {
                    BucketName = bucketName,
                };
                GetBucketWebsiteResponse getResponse = await client.GetBucketWebsiteAsync(getRequest);
                Console.WriteLine($"Index document: {getResponse.WebsiteConfiguration.IndexDocumentSuffix}");
                Console.WriteLine($"Error document: {getResponse.WebsiteConfiguration.ErrorDocument}");

bool AwsDoc::S3::GetWebsiteConfig(const Aws::String &bucketName,
                                  const Aws::Client::ClientConfiguration &clientConfig) {
    Aws::S3::S3Client s3_client(clientConfig);

    Aws::S3::Model::GetBucketWebsiteRequest request;
    request.SetBucket(bucketName);

    Aws::S3::Model::GetBucketWebsiteOutcome outcome =
            s3_client.GetBucketWebsite(request);

    if (!outcome.IsSuccess()) {
        const Aws::S3::S3Error &err = outcome.GetError();

        std::cerr << "Error: GetBucketWebsite: "
                  << err.GetMessage() << std::endl;
    }
    else {
        Aws::S3::Model::GetBucketWebsiteResult websiteResult = outcome.GetResult();

        std::cout << "Success: GetBucketWebsite: "
                  << std::endl << std::endl
                  << "For bucket '" << bucketName << "':"
                  << std::endl
                  << "Index page : "
                  << websiteResult.GetIndexDocument().GetSuffix()
                  << std::endl
                  << "Error page: "
                  << websiteResult.GetErrorDocument().GetKey()
                  << std::endl;
    }

    return outcome.IsSuccess();
}

The following command retrieves the static website configuration for a bucket named my-bucket:

aws s3api get-bucket-website --bucket my-bucket

Output:

{
    "IndexDocument": {
        "Suffix": "index.html"
    },
    "ErrorDocument": {
        "Key": "error.html"
    }
}

Get the website configuration.

import { GetBucketWebsiteCommand, S3Client } from "@aws-sdk/client-s3";

const client = new S3Client({});

export const main = async () => {
  const command = new GetBucketWebsiteCommand({
    Bucket: "test-bucket",
  });

  try {
    const { ErrorDocument, IndexDocument } = await client.send(command);
    console.log(
      `Your bucket is set up to host a website. It has an error document:`,
      `${ErrorDocument.Key}, and an index document: ${IndexDocument.Suffix}.`,
    );
  } catch (err) {
    console.error(err);
  }
};

Example 1: This command returns the details of the static website configurations of the given S3 bucket.

Get-S3BucketWebsite -BucketName 's3testbucket'