A Hazel alternative with on-device AI
Hazel by Noodlesoft has been around since 2006 and costs $42. It is a mature tool for folder rules. So why look at an alternative?
What Hazel does well
Hazel checks files by name, type, date, size and text and then acts: move, rename, tag, run scripts and much more. If you like regular expressions and date patterns, you can build very precise rules. If your Hazel rules work, there is no reason to switch.
Where patterns hit limits
Patterns find text but don't understand it. An invoice from a new vendor looks different, a scan has no text layer, an amount appears as “12,34 €” one time and “EUR 12.34” the next. Each case needs its own rule.
What “on-device AI” means
Since macOS 26, apps can use Apple's language model directly on the Mac (Foundation Models, part of Apple Intelligence). It runs offline, with no per-request cost, and no file leaves the Mac. The model is small: good for short, clear questions such as “what kind of document is this, from whom, from when, for what amount”, not for long texts. It needs a Mac with Apple silicon and Apple Intelligence turned on.
What to look for
- Local: files and text stay on the Mac, no cloud AI.
- Readable: every rule can be checked before it runs.
- Dry run: you see what would happen first.
- Undo: every action can be reversed.
- Honest when unsure: ask rather than file wrongly.
How Letterslot compares
Letterslot uses rules like Hazel (name, type, age, size, text) and also understands content: kind, sender, date and amount. You can describe a rule in one sentence and check it as a sentence and a form. A dry run on the newest 50 files comes first; afterwards every action is in the journal, with Undo. Amounts and dates are cross-checked with fixed patterns; when in doubt the file waits as “Please check”.
Hazel has more actions and also runs on older macOS versions. Letterslot needs macOS 26, and its AI features need Apple silicon and Apple Intelligence. Without AI, Letterslot works with name, type, age, size and text only, much like Hazel.
Letterslot is a file autopilot for the Mac: it reads new files, understands them with Apple's on-device language model and files them by your rules, with a journal and Undo. 14 days of everything free, then free with 2 rules or Pro for €24 once.
See Letterslot