The hotkey is the entire interface. Pick a bad one and you will discover it three weeks later, in Xcode, when the shortcut you rely on everywhere else silently does something different.
Here is how to pick one that holds.
The three tiers of “taken”
Shortcuts on macOS are claimed at three levels, and only the first is visible to you.
- System shortcuts — reserved by macOS.
⌘Space,⌘Tab,⌃↑. You can rebind these in System Settings, but you should not; muscle memory across machines is worth more than any single shortcut. - App shortcuts — claimed by whatever is frontmost. These are the dangerous ones, because a shortcut can be free in Slack and Chrome and taken in Figma, so it works for weeks before it doesn’t.
- Other utilities — Raycast, Alfred, Rectangle, CleanShot, Karabiner. Frequently invisible until they collide, because they register globally and consume the event before the frontmost app ever sees it.
Most bad hotkey choices are tier 2 or 3.
What is actually free
In practice, these are reliably unclaimed:
| Shortcut | Notes |
|---|---|
⌘' |
Free in nearly everything. One modifier, easy reach. |
⌘⌥E |
Our default. Safe, but a stretch. |
⌘⌥; |
Free everywhere we have tested. |
⇪ remapped |
Genuinely free if you do not use Caps Lock. |
Double-tap ⌘ |
No collision surface at all. |
And these look free but are not:
| Shortcut | Claimed by |
|---|---|
⌘E |
“Use Selection for Find” in most native apps; Export in Figma |
⌘R |
Reload / Run — browsers, Xcode, everything |
⌘K |
Slack quick switcher, VS Code chord prefix, link insert |
⌘⇧A |
Actions in Chrome, Select All Text in some editors |
⌥Space |
Raycast and Alfred both default here |
Test a candidate in two minutes
Do not test in one app. Open the five surfaces where you write most — for most people that is Slack, a browser text field, Mail, your editor and Notion — and in each one:
- Select a few words.
- Press the candidate.
- Note whether anything other than Promptshot happens.
The failure you are looking for is not “nothing happened”. It is “something else happened”, especially something quiet like a mode toggle. Xcode and Figma are the two most likely to surprise you, so include them if you use them at all.
If you use Karabiner-Elements, check its event viewer while testing. A shortcut consumed by a Karabiner rule never reaches Promptshot and never reaches the app either, which produces the most confusing possible symptom: nothing happens anywhere.
The case for double-tap ⌘
Under Settings → Hotkey → Advanced you can bind a double-tap of a bare modifier instead of a chord. It has one real advantage: the collision surface is zero, because no app binds a modifier tapped twice.
The trade is a ~180 ms detection window, since we have to wait long enough to know a second tap is not coming. That is 180 ms added to every invocation. If you rewrite forty times a day, chords are worth the setup effort; if you rewrite five times, take the free option.
Per-profile modifiers
Once you have a base hotkey that survives everything, profile modifiers come free — ⇧, ⌥ and ⌃ layered on a chord that already works will also work. Test the base thoroughly and the variants inherit its safety.
That is the whole point of the design: one decision, made carefully, once.