Performance Comparison of css-in-js Libraries

Libraries compared:

About the setup:

  • This is a Next.js SSR repository with three URLs – one for linaria (/linaria), one for styled components (/styled-components) and one for the css modules (/regularcss).
  • All the URLs load the same component – containing 22 buttons that change their color every 1 second as the React component is rerendered (via state change).
  • The styling CSS for these URLs is setup to be generated on the SSR and set internal via <style> tag within the page’s HTML.
  • The URLs are:
    • /linaria – the page’s styling is handled via linaria.
    • /styled-components – the page’s styling is handled via styled components.
    • /regularcss – CSS modules.

Page Loading Performance:

  • The page loading test was done via WPT (Fast 3G – Virginia, US – Emulated Moto G4):
  • The start render for the linaria page was 1.6s as compared to the same for styled-components at 1.5s. (Need to delve deeper to understand why.)
  • The JS loaded for /linaria is 77 kB gzipped while the same for /styled-components is 89 kB. This difference can be attributed to the difference in the size of the two packages.

Re-rendering Performance:

  • The rerendering performance was measured by loading the page on Xiaomi Mi A2 mobile (on Chrome 94.0.4 measured via Remote Debugging devtools – Performance tab).
  • The library versions for this run were – linaria 3.0, styled components 5.3.3
  • The runs were undertaken 5 times and below are the median numbers:

Relavent reading material:

GitHub

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