Slipcase Desktop
Metadata that travels along
Only for Mac
Free
Mac
Make a container out of a file, or open one and read the metadata that travelled with it. Edit that metadata in place, and hand the payload to whatever opens it.
A Slipcase container is one file holding a document of any type together with metadata describing it. Copy the container, send it, or move it to another machine and the metadata goes too — instead of living in a filename that gets truncated, a sidecar file that gets separated, or a database on somebody else's computer.
Slipcase opens a container and shows what is inside, and makes one out of a file you choose.
WHAT YOU SEE
The payload's name and size. What your operating system says would open it. The metadata as a tree, with every value editable in place. And the container's verdict against the specification, in the specification's own words — including the two answers that are neither a pass nor a failure: a container whose metadata cannot be read is undetermined, and one written to a newer version of the format is out of scope.
WHAT YOU CAN DO
Open hands the payload to whatever application is registered for that kind of file. Extract writes it somewhere you choose. Replace swaps it for a different file. Save writes an edited metadata document back — keeping your comments, your key order, and any whitespace you did not touch, along with anything else in the container that Slipcase does not recognise.
A rewrite is read back and checked before it replaces anything, so a save that would produce a container the format does not accept changes nothing on disk. A container you did not change is not rewritten at all.
New container asks which file to put in and where the container should go, writes it, and then opens it, so the metadata is filled in where the rest of it gets edited. A large payload packs with a progress bar and a Stop, and stopping leaves nothing behind. A file the format will not accept as a payload is refused when you choose it, rather than after you have said where the container goes.
WHAT IT TELLS YOU, AND DOES NOT DECIDE FOR YOU
Slipcase reports. It does not gate.
If a container arrived from elsewhere — downloaded, or sent to you — Slipcase says so, and the payload you extract is marked as well, so your computer treats it with the caution it gives anything that came from outside rather than opening it as though you had made it yourself. Editing the metadata and saving does not quietly erase that: Slipcase still tells you where the container came from afterwards. It travels the other way too: a file that arrived from elsewhere still says so on the container you pack it into.
On macOS it tells you when a payload was stored as an executable file, and that the copy you extract will not be. That is read out of the container rather than guessed from its name.
Names are shown with the characters that reorder text written out, so a payload cannot present itself as one kind of file while being another.
Where your operating system will not say what opens a payload, Slipcase says nothing rather than guessing. It ships no table matching filenames to types and never inspects a payload's contents to guess at one. What you get is information — where the file came from, what it was, whether the container is well formed — and the decision stays yours.
WHAT IT DOES NOT DO
No network connection of any kind. No account. No telemetry, no analytics, no crash reporting. Nothing about you or your files is sent anywhere, because there is nowhere for it to be sent.
It shows no preview: the payload is handed to another application rather than rendered here. A container holds one payload, which is the format's decision rather than this application's.
OPEN SOURCE
Slipcase is open source, and so is the format it reads and the library that reads it. Every claim above is checkable: github.com/excelano/slipcase-desktop.
Ratings & Reviews
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The Slipcase container type is now registered. IANA assigned application/vnd.excelano.slipcase+zip on 16 September 2026, and Slipcase registers containers under that name on Windows, macOS and Linux. The provisional name it replaces belonged to a tree meant for closed settings, which is not where a format that ships in application stores belongs.
No container changes. The type has never been written inside one, so files made by earlier versions are the same files: they open the same way and keep the same icon. On Linux the old name still resolves, because the media type database records it as an alias of the registered one. On Windows and macOS, which have no such mechanism, installing this version replaces the old registration rather than leaving it beside the new one.
There is nothing to choose and nothing to migrate.
The developer, Excelano LLC, indicated that the app’s privacy practices may include handling of data as described below. For more information, see the developer’s privacy policy .
Data Not Collected
The developer does not collect any data from this app.
Accessibility
The developer has not yet indicated which accessibility features this app supports. Learn More
Information
- Seller
- Excelano LLC
- Size
- 8.7 MB
- Category
- Utilities
- Compatibility
Requires macOS 12.0 or later.
- Mac
Requires macOS 12.0 or later.
- Mac
- Languages
- English and German
- Age Rating
4+
- 4+
- Copyright
- © 2026 Excelano LLC