Switching Themes

Ask Me Anything Q&A Themesofficehoursrepo

Topic summary

The decision to switch themes versus building on an existing one depends on several key factors:

When switching is recommended:

  • Old themes built with outdated technologies (no lazy loading, unnecessary libraries like jQuery) that hinder site speed improvements
  • Accumulated code remnants from previously tested apps that are difficult to remove
  • Incompatibility with newer Shopify platform features and functionality
  • Themes with zero performance that cannot be optimized further

When building on existing themes works:

  • Theme still loads quickly and can be restored to efficient status with developer help
  • Theme hasn’t been heavily modified and has room for optimization
  • Modern themes now support significant customization through “Custom CSS” settings and “Custom liquid” sections without code editing, making updates easier while preserving new functionality and fixes

The consensus is to evaluate your current theme’s performance, code cleanliness, compatibility with modern Shopify features, and modification history before deciding.

Summarized with AI on October 28. AI used: claude-sonnet-4-5-20250929.
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In reality, is it best to switch a theme or just build on what you already have?

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This depends on what you already have and what you want to add.

Often people have old themes and want to, say, make them faster. Unfortunately, often it is not possible because of the choices made during the theme design stage – old technologies, no lazy loading, use of libraries which were useful before, but not needed now, like jQuery. In this case it is usually better to upgrade to a modern theme which was built with site speed in mind. Some things were not important then, but important now and fixing them would be very time-consuming.

If your theme has a lot of leftovers from the multiple apps you’ve tried over the years you may need to remove those and again, starting from scratch can be easier.

Often new themes offer new functionality – Shopify evolves as a platform and new features added frequently – old themes may require serious modifications to be compatible.

Finally, now it is possible to significantly change the look and feel of your store without editing theme code, just by using “Custom CSS” settings and “Custom liquid” sections. This will make updating to newer theme versions easy and ensure that you continue getting new functionality/fixes.

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Hi @Ainspire1

The key points you need to check whether switch a theme or build on the existed theme are related with four aspects. You can regard them as reference and see if meet your demands:

  1. Your existed theme has zero performance and has no other ways to optimize but switch.

  2. There exist too many codes left from other apps and you feel quite hard to identify them one by one.

  3. The existed theme still loads fast and with the help of developers, it can be returned back to the efficient status again.

  4. The theme is not strongly modified before and you still have further places to optimize or improve.

Above four factors are the ones you need to note here, and by double checking your current theme real situation, you should know if need to switch or optimize the original one still. Thank you!