Features
Smart Compress
Compress by goal instead of by level 1–9. Archydes estimates size and time and recommends the right format.
How much something compresses depends on its contents, not on the setting. Text and code shrink to a fraction of their size, while photos, videos and music are already compressed and barely get smaller. That’s why Smart Compress looks at the contents before you compress.
The four goals
| Goal | Format | Use it for |
|---|---|---|
| Fast | ZIP | When you’re in a hurry or the contents are already compressed. |
| Balanced | ZIP | Good size, opens everywhere. The right choice for sharing. |
| Smallest | 7z, maximum compression | As small as possible, takes longer. |
| Long-term archive | 7z with SHA256SUMS | For keeping: checksums show later whether every byte is still intact. |
You find the goals in the save dialog under Goal. Custom setting shows format and level, as you know them from other apps.
Estimate and recommendation
Archydes compresses a sample of about 8 MB from all file types and uses it to project size and time for each goal. In testing, the estimate was usually within ±25%.
The recommendation appears above the file list and is preselected with ★ in the save dialog, along with a reason, for example:
- the contents are already compressed, stronger compression saves hardly any space
- “Smallest” saves only a little more and takes much longer
Click Why? to see the breakdown by file type (photos, videos, text and code, documents…) with the expected savings for each.
Long-term archive and checksums
With the Long-term archive goal, Archydes adds a SHA256SUMS file to the archive, in the same format as shasum -a 256 in Terminal. When you open the archive again later, the safety check compares every file with its checksum. That way, you’ll notice if a disk or cloud storage has damaged something.
If you edit such an archive, Archydes recalculates the checksums when you save.