Uniquer

Uniquer is a very small npm package with one job: when you ask it to save a file, it only actually writes the file if the same content has not been saved before. Same bytes, same file. Different bytes, new file. No duplicates, no manual bookkeeping.

Under the hood it’s about as simple as you would expect: hash the contents with SHA-256, use that hash (plus the extension) as the filename, and skip the write if the file already exists on disk. A few benefits fall out of that: no more clever naming schemes, no wasted disk space from near-identical uploads, and fewer unnecessary writes on slow storage.

It’s one of those tiny utilities I wrote for a specific project and then kept reaching for. If you have ever built an upload pipeline, a caching layer, or anything that accidentally grows a “duplicates” folder, it’s the kind of thing that pays for itself quickly.