Fingerprinting

• Is a unique hash added to a file’s name (or query string) so browsers know when the file has changed.

• Example:

  • app.css  → app.3f91c2.css

• The HTML must point to the exact hashed filenames produced by your build.

  • If the file is named studies-index.76216.css  on disk, that is what the HTML must reference.

• On every deploy, if the hash changes, the HTML needs to be updated to point to the new name.

  • This is why most setups use a build step or template system that injects the correct filenames automatically.

• You can’t  keep name.css  and expect caching to invalidate when content changes. The hash name is the cache-busting mechanism.

• Working example:

<link rel="stylesheet" href="/static/studies-index.76216.css">
<script src="/static/studies.76216.js"></script>