macOS · menu bar

Make any key
into any other key.

Record a chord or a sequence, pick the output, and it's remapped system-wide. No config files, no key codes to memorize.

Requires macOS 13+ · Accessibility permission

+
5

press ⌥ + Numpad 5 — it moves the cursor down

What it does

Three ways to remap

⌥5

Chords

Modifier plus a key — ⌥ + Numpad 5 — becomes any single key you choose.

A→S

Sequences

Type keys in order within a second (A → S → D) to fire one output. Like a chord for time instead of space.

⌃⌥R

Global toggle

Record a hotkey that turns remapping on or off from anywhere — even while it's off.

Setup

Record, don't configure

1

Record the trigger

Click Record and press the keys — held modifiers show live as you press. No looking up virtual key codes.

2

Record the output

Press the key you want instead. Save the rule; it's stored in ~/Library/Application Support/KeyModifier.

3

Grant Accessibility, flip it on

Allow Key Modifier in System Settings once. The tap starts automatically — toggle remapping from the menu bar or your shortcut.

Free · open source

Get Key Modifier

Download the latest build, unzip, and drop it in Applications.

Download the latest release

First launch is blocked because the build isn't notarized. Clear it once:
xattr -dr com.apple.quarantine "/Applications/Key Modifier.app"