How to archive a finished project so it takes 5 percent of the space
Most of a finished project is derived data. What to strip, what to keep, and how to make the archive still usable in three years.
A finished project folder is mostly things a computer produced: build output, render caches, optimised media, dependency folders. Stripping those before archiving routinely takes a project to a twentieth of its size, and none of it is lost in any meaningful sense.
What to strip, by kind of project
| Project | Remove | Keep |
|---|---|---|
| Software | node_modules, target, build, .next, caches | Source, lock files, README |
| Video | Render cache, optimised media, proxies | Project file, source footage, final export |
| Audio | Freeze files, bounces of stems | Session, recordings, final mix |
| Design | Preview caches, exported variants | Source documents, delivered assets |
| Data | Prepared dataset copies, model caches | Notebooks, raw data, results |
The rule for deciding
Ask what it would take to recreate the file. If the answer is running a command, it goes. If the answer is redoing work, or if it cannot be recreated at all, it stays. The awkward middle is anything that took hours of compute, which is worth keeping precisely because the recreation is expensive.
Keep the instructions with it
An archive that cannot be rebuilt in three years is not an archive. A short note in the folder saying which versions it used, how to build it, and where the original inputs came from is worth more than any amount of extra data:
cat > ARCHIVE-NOTES.md <<'EOF'
Built with: Node 20.11, pnpm 9
Restore: pnpm install && pnpm build
Source footage: originally from SD card, October 2025
Removed before archiving: node_modules, .next, render cache
EOFCompressing what is left
cd ~/Projects
tar -czf project-2025.tar.gz project-folder
ditto -c -k --sequesterRsrc --keepParent project-folder project-2025.zipditto is the macOS aware option and preserves resource forks and metadata that zip can lose. For folders that are mostly already compressed media, expect very little gain, which is covered in when compressing actually saves space.
Where to put it
An external drive is the usual answer, with the important caveat that one copy is not a backup. Two copies, or one copy plus a cloud upload, is the minimum for anything you would be upset to lose, and what moves safely to an external drive covers the mechanics.
Common questions
What should I remove before archiving a project?
Anything generated: dependency folders, build output, render caches, optimised media and freeze files. Keep source files, lock files, original media and the final export.
How do I compress a project folder on a Mac?
Use ditto -c -k --sequesterRsrc --keepParent, which preserves Mac metadata, or tar for cross platform archives. Folders of already compressed media gain very little from either.
How much space does archiving save?
Frequently 90 percent or more, because most of a finished project is derived data. A software project without its dependency folder and build output is often a twentieth of its working size.
What makes an archive still usable years later?
A short note recording the tool versions, the build command and where the original inputs came from. Without it, an archive that technically restores may be impractical to rebuild.