http_conditional_caching

🌐 HTTP Conditional Caching with ETag & Last-Modified

Offload repeated view rendering by leveraging HTTP 304s with ETags and Last-Modified headers. Rails can automatically set ETags for your responses, enabling clients and proxies to skip fetching unchanged content.

# app/controllers/articles_controller.rb
class ArticlesController < ApplicationController
  def show
    @article = Article.find(params[:id])
    fresh_when(etag: @article.cache_key_with_version, last_modified: @article.updated_at)
  end
end

With this, browsers will send If-None-Match or If-Modified-Since, and Rails will return 304 Not Modified when appropriate, saving bandwidth and rendering time.