If you want to optimize for speed, I'd recommend using Nokogiri, but not the Nokogiri::XML::Builder which will perform about as well as the Builder gem. Instead, use the lower-level Document and Node APIs. Here's some code showing equivalent document construction for Builder, Nokogiri::XML::Builder, and Nokogiri::XML::Document ... and a benchmark if it's helpful (higher numbers are better, it's iterations per second): ```ruby #! /usr/bin/env ruby require "bundler/inline" gemfile do source "https://rubygems.org" gem "builder" gem "nokogiri" gem "benchmark-ips" end require "builder" require "nokogiri" require "benchmark/ips" N = 100 # using Builder::XmlMarkup, build an XML document representing attributes of a person def builder_person xml = Builder::XmlMarkup.new xml.people do |p| N.times do xml.person do |p| p.name "John Doe" p.age 42 p.address do |a| a.street "123 Main Street" a.city "Anytown" end end end end end # using Nokogiri::XML::Builder, build an XML document representing attributes of a person def nokogiri_person Nokogiri::XML::Builder.new do |xml| xml.people do N.times do xml.person do |p| p.name "John Doe" p.age 42 p.address do |a| a.street "123 Main Street" a.city "Anytown" end end end end end.to_xml end # use Nokogiri's bare API to build an XML document representing attributes of a person def nokogiri_raw_person xml = Nokogiri::XML::Document.new xml.root = xml.create_element("people") N.times do xml.root.add_child(xml.create_element("person")).tap do |p| p.add_child(xml.create_element("name", "John Doe")) p.add_child(xml.create_element("age", 42)) p.add_child(xml.create_element("address")).tap do |a| a.add_child(xml.create_element("street", "123 Main Street")) a.add_child(xml.create_element("city", "Anytown")) end end end xml.to_xml end puts RUBY_DESCRIPTION # pp builder_person # pp nokogiri_person # pp nokogiri_raw_person Benchmark.ips do |x| x.report("builder") { builder_person } x.report("nokogiri") { nokogiri_person } x.report("nokogiri raw") { nokogiri_raw_person } x.compare! end ``` ``` ruby 3.2.2 (2023-03-30 revision e51014f9c0) [x86_64-linux] Warming up -------------------------------------- builder 58.000 i/100ms nokogiri 49.000 i/100ms nokogiri raw 61.000 i/100ms Calculating ------------------------------------- builder 541.580 (± 6.5%) i/s - 2.726k in 5.054535s nokogiri 451.127 (± 7.5%) i/s - 2.254k in 5.027192s nokogiri raw 681.437 (± 9.1%) i/s - 3.416k in 5.061582s Comparison: nokogiri raw: 681.4 i/s builder: 541.6 i/s - 1.26x slower nokogiri: 451.1 i/s - 1.51x slower ``` On Thu, May 18, 2023 at 8:02 AM Austin Ziegler via ruby-talk < ruby-talk(a)ml.ruby-lang.org&gt; wrote: