For my own realtime browser based ASCII projects I update the DOM “manually”: the biggest bottleneck is frequent -horizontal- changes in color as each character

For my own realtime browser based ASCII projects I update the DOM “manually”: the biggest bottleneck is frequent -horizontal- changes in color as each character with a new color needs to be wrapped in its own <span> element. After all you can’t avoid a DOM repaint. After several benchmarks I realized that the fastest way to update the entire window is to compose a string and assign it to each line/line-element via innerHTML. I usually get 60fps with 5-8k chars in fullscreen (browser text rendering has become really fast).