WP CSS Merge
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Safely combines compatible local stylesheets into cached bundles while preserving WordPress dependency order and automatic fallbacks.
WP CSS Merge reduces compatible frontend stylesheet requests by combining local CSS files into cached bundles.
Version 2 uses a safety-first bundle engine:
- Preserves the dependency and cascade order managed by WordPress.
- Creates different bundles for different style sets instead of sharing one global file.
- Keeps external, inline, conditional, RTL, unsupported, and excluded styles unchanged.
- Rebases relative image and font URLs to their original public locations.
- Writes cache files atomically in the current site’s uploads directory.
- Automatically serves the original stylesheets whenever bundling is unavailable or unsuccessful.
- Invalidates bundles when source files, versions, settings, locale, or queued style combinations change.
- Supports multisite with a separate cache location for each site.
The plugin never downloads remote CSS, contacts external services, or sends telemetry.
Because HTTP/2 and HTTP/3 reduce the cost of multiple requests, combining every stylesheet is not always faster. WP CSS Merge therefore combines only contiguous styles that can be moved safely without changing their behavior.