Learn
Your first conversion
This takes about thirty seconds, and you need a file you do not mind a copy of. A photo is ideal.
Do it now
Find a photo in Finder. Any HEIC from your phone, or a PNG, or a JPG.
Press and hold on it, and start to drag — the same movement as dragging it into another folder. Keep the button down.
Now hold ⇧. A ring appears around your cursor with a format in each slice. The file's own name sits in the middle.
Move toward one of them. The slice under the cursor lights up. You are not committed to anything yet: move back to the middle and nothing happens.
Let go. The converted file appears beside the original, in the same folder, with the same name and a new extension.
That is the whole app. Everything else is a variation on it.
What just happened
Arazio watched the drag, noticed the modifier, and offered the formats that this particular file can become — a photo offers image formats and PDF, a video offers video formats and audio ones. The list is not fixed; it is computed from what the file is.
The conversion ran on your Mac. Nothing was uploaded, and nothing needed a network: the conversion engines have no networking code in them at all, and a test fails the build if a networking symbol appears in one.
If the ring did not appear
The usual cause is permission. Arazio watches for a modifier during a drag, and macOS requires Accessibility permission for that.
Open System Settings → Privacy & Security → Accessibility and make sure Arazio is listed and switched on. If it is listed and on and the ring still does not appear, switch it off and on again — macOS occasionally keeps a stale permission after an update.
More on this if it is still not behaving.
The original is never touched
Every conversion writes a new file. The one you dragged is exactly as it was, in the same place. Nothing is overwritten, and nothing is deleted — if you want the original gone, you delete it yourself.
Next
The ring you just used is one of three. The three rings is the next minute of your life.