Skip to main content

Archive, compress & encrypt — how they compose

Most archive utilities fuse three different jobs into one “make a zip” button: they bundle your files, compress them, and (sometimes) encrypt them — all baked into a single format choice. Purrchiver keeps them three separate tools, so you can use any one on its own or stack them in whatever order fits the job.

The three tools

Archive — bundle many into one

Packing files and folders into a single container: ZIP, 7z, tar, Apple Archive (AAR), ISO 9660, CPIO, DMG. You can bundle without compressing — a plain .tar, or the None option, which pairs with age encryption to lock a single file without compressing it. See Creating a new archive.

Compress — make it smaller

Shrinking the bytes, two ways:

  • Inside an archive — pick a compression level (Store / Fast / Normal / Best), or a compressed-tar variant (.tar.gz, .tar.zst, .tar.xz, …).
  • On a single file — the Compress File verb writes a standalone stream: gz, bz2, xz, zstd, brotli, lz4, lzip, lzma. No container, just a smaller file.

Encrypt — lock it

Protecting the contents with a password. Several tools, because different recipients need different things:

  • ZIP + AES-256 — broadest compatibility.
  • 7z + AES-256 — strong; filenames hidden too (header-encrypted).
  • AEA — Apple’s Encrypted Archive (hides everything; Apple platforms).
  • Encrypted DMG — an AES-256 disk image.
  • age — the universal wrap that encrypts any container or single file, even ones with no built-in encryption of their own.

See Encrypted archives and age encryption.

Composing them

Because the three are independent, you mix them to fit the job:

You wantToolsExample result
Just bundleArchiveProject.tar
Just shrink one fileCompressreport.csv.gz
Just lock one fileEncryptsecret.pdf.age
Bundle + shrinkArchive + CompressProject.tar.zst, Project.7z
Bundle + lockArchive + EncryptProject.zip (AES-256)
Shrink + lockCompress + Encryptreport.csv.gz.age
All threeArchive + Compress + Encryptan encrypted, compressed 7z — or Project.tar.zst wrapped in age

The standout is age: because it wraps the finished file, it composes over anything — a .tar.zst, an .iso, an Apple Archive, a lone .gz — so you can encrypt containers no other Mac archiver can.

Where each one lives

Free vs. the unlock

Bundling the common formats and compressing to gz / bz2 are free; the advanced create formats, all encryption, and split volumes are part of the one-time $9.99 unlock. See What’s free vs. the unlock.