Using Surge’s automatic Lucid Caching
When you publish to Surge, a strategy we call Lucid Caching is automatically applied:
- Gzip is enabled for all appropriate content types
- Far-future expiry headers are properly set
Every asset, including HTML, is served with the following Cache-Control directive, and an ETag validator:
Cache-Control: public, max-age=31536000, no-cache ETag: "0f31201287e0e3f7e87c86ed26f2a492"
This tells your visitors’ browsers they may store the asset for a year, but must validate the cache before serving it.
Surge then uses ETags to force the cache validation, ensuring the client doesn’t serve a stale asset. This means:
- The browser never downloads the same asset twice—not even
- The server never serves a stale file.
- The developer never has to rename files, or change asset paths to cache bust.
- The end-user’s browser cache is not abused.
As far as we’re aware, this is the most aggressive front-end caching strategy that can be put together without ever serving stale content. It’s applied automatically when you publish with Surge.