Version 0.5.0+

Prevents using theme JavaScript files and external scripts with a compressed size greater than the configured threshold_in_bytes. Limiting the size of JavaScript files helps to improve the performance of your theme.

You occasionally might need to load large JavaScript bundles. In these cases, you can use an import on interaction pattern to avoid having users who don't interact with a component execute the bundle.


The following examples contain code snippets that either fail or pass this check.

✗ Fail

In the following example, assets/chat-widget.js is greater than 10 KB gzipped:

✓ Pass


The following example contains the default configuration for this check:

For themes:

For theme app extensions:

Parameter Description
enabled Whether this check is enabled.
severity The severity of the check.
threshold_in_bytes The maximum allowed compressed size, in bytes, for a single JavaScript file. This includes the theme and remote scripts.

Disabling this check

This check is enabled by default only when you run shopify extension check. This limit is not yet enforced, but disabling this check isn't recommended for theme app extensions.

If you can't avoid violating the rule, then you should disable the check using the comment syntax. This ensures that you intentionally disable the check for each instance.