Get table from http://docs.aws.amazon.com/AmazonS3/latest/dev/WebsiteEndpoints.html

getS3WebsiteEndpoint.js

// Table copied from
// http://docs.aws.amazon.com/AmazonS3/latest/dev/WebsiteEndpoints.html

export default (region, bucket) => ({
  'us-east-1': `${bucket}.s3-website-us-east-1.amazonaws.com`,
  'us-west-1': `${bucket}.s3-website-us-west-1.amazonaws.com`,
  'us-west-2': `${bucket}.s3-website-us-west-2.amazonaws.com`,
  'ap-south-1': `${bucket}.s3-website.ap-south-1.amazonaws.com`,
  'ap-northeast-2': `${bucket}.s3-website.ap-northeast-2.amazonaws.com`,
  'ap-southeast-1': `${bucket}.s3-website-ap-southeast-1.amazonaws.com`,
  'ap-southeast-2': `${bucket}.s3-website-ap-southeast-2.amazonaws.com`,
  'ap-northeast-1': `${bucket}.s3-website-ap-northeast-1.amazonaws.com`,
  'eu-central-1': `${bucket}.s3-website.eu-central-1.amazonaws.com`,
  'eu-west-1': `${bucket}.s3-website-eu-west-1.amazonaws.com`,
  'sa-east-1': `${bucket}.s3-website-sa-east-1.amazonaws.com`
}[region])

${bucket}.s3-website-<region>.amazonaws.com is applicable for all regions, see http://docs.aws.amazon.com/general/latest/gr/rande.html#s3_region while the . notation is not. I agree the examples from your links are a bit misleading, generally it would be good that the 2 forms are always available