For Apple silicon Macs · macOS 15 or later
Every display control your Mac hides.
And plain answers when something's wrong.
Brightness, resolution, refresh rate and HDR from the menu bar. When a monitor misbehaves, it names the cause and the fix.
Launch price · 100 of 100 Macs left · One-time purchase · 14-day refund
- Notarized by Apple
- No analytics in the app
2 displays
Try it
The whole menu bar app. Right here.
Built-in Display · 1512×982 · 120 Hz
DELL U2723QE · 2560×1440 · 60 Hz
A live demo of the app's menu. Try the size slider, Hz or Rotate, then answer “Keep this?”, or wait 15 seconds.
Peak brightness
The brightness your MacBook Pro saves for HDR. Now for everything.
Illustration. A web page can't go brighter than your screen allows, so “off” is drawn dimmer here.
Peak brightness
Use the brightness your screen keeps for HDR video for everything.
everyday1,000
full screen1,600
peak
Apple's figures for the 14″ and 16″ MacBook Pro with M1 Pro to M3 Max. The app shows the peak macOS reports for your screen. macOS still holds large bright areas lower to protect the panel, and screenshots don't include the extra brightness.
Peak in the menu bar
Open a display's controls and click Peak. A level slider appears under brightness.
A switch in Brightness
On each display that can do it, with the level and the peak macOS reports for that screen.
⌥⌘B from anywhere
Displays › Peak Brightness. Or peak.on and peak.off from ikmd, Shortcuts and links.
Keys past the maximum
Optional: at full brightness, brightness up keeps going into peak. Needs Accessibility.
Diagnose
Stuck at 30 Hz? Find out why in a second.
Mac
MacBook Pro 14″/16″ (M4 Pro)
Link
HDMI 1.4
Monitor
4K · 60 Hz
Reduced · High confidence
4K at 30 Hz, not 60 Hz
- 4K at 60 Hz needs 12.54 Gbps, but HDMI 1.4 carries 8.16 Gbps.
- Fix: use the Mac's own HDMI port (HDMI 2.1) or a direct USB-C cable.
- This Mac drives up to 2 external displays on its own.
- On M4 and M5 Macs, macOS doesn't offer the sharp “looks like 3840×2160” size on 4K monitors; the largest sharp size it lists is smaller. iKnowMyDisplay's Sharp 4K fix adds it, where your Mac supports it.
From published specs and the bandwidth each mode needs. The app reads your real link and names the hop that limits it.
- 4K stuck at 30 Hz behind an HDMI 1.4 hub
- A USB-C link too slow for 4K at 60 Hz
- “High data speed” halving the display lanes
- HDMI 2.0 with 10-bit colour over budget
- A DisplayLink dock in the path
- Sharp 4K missing on M4 and M5
- Soft text on 1440p monitors
- Detected, but no picture
- More displays than your Mac drives
- A mode macOS doesn't offer
- Daisy-chaining macOS doesn't support
- Repeated drops or flicker today
Brightness
From black to brighter than 100%.
Virtual screens and picture in picture
Screens that exist only in software.
Messages
Your screen
Virtual 1920×1080 · sharp
Share one screen in a call, keep the rest yours
Add a virtual screen, drag the slides onto it, and share only that in Zoom, Meet or Teams. Your mail, chats and notifications stay on your own screen.
Colour
Colour, your way.
Look (3D LUT from a .cube file)
Colour profiles switch by themselves between SDR and HDR. Flicker reduction and colour modes work where your Mac supports them.
History
Proof of what your displays did.
Built-in Display
Dell U2723QE · CalDigit TS4
LG 27UP850 · USB-C hub
Automate
Every action, from anywhere.
~ %
Rules
Also when the Mac wakes, or at a time of day.
Keyboard shortcuts for any action
Restore everything, from anywhere. Give any other action its own shortcut.
Shortcuts
Every action as a Shortcuts step: set brightness, switch input, apply a preset, run a diagnosis.
Links and HTTP
iknowmydisplay:// links, and a local HTTP API on 127.0.0.1 with a token. Off until you turn it on.
Scripts and console
Run your own script when a display connects, sleeps or wakes, and read every step in the log console.
Everything it does
41 things it does. One app.
Diagnose
Plain-words diagnosis
What's wrong, why, and the steps to fix it, with how sure the app is.
Diagnose
Connection chain and bandwidth
Mac port, hub or dock, monitor input, and what each hop can carry.
Diagnose
Monitor data (EDID)
Model, native mode, supported timings and HDR data, with export.
Diagnose
Connection history
Connects, drops, flickers, mode changes, sleep and wake, kept on your Mac.
Diagnose
Notch alerts
A display came up below what it can do, or dropped 3 times in 10 minutes.
Brightness
Monitor controls over the cable
Brightness, contrast, volume, mute, input, standby and colour gains (DDC).
Where your Mac supports it
Brightness
Dim to black
Hardware and software brightness as one slider, down to black.
Brightness
Brightness and volume keys
Your keys work on external monitors, with the app's own on-screen display.
Brightness
Peak brightness
The brightness your XDR or HDR screen keeps for HDR video, for everything. One switch, or ⌥⌘B.
Where your Mac supports it
Brightness
Brightness sync in nits
Group displays and move them together, matched by real brightness.
Resolution
Resolution slider and favourites
Every size on one slider, with starred sizes in the menu.
Resolution
Hidden refresh rates
Refresh rates the monitor offers that macOS keeps out of Settings.
Safe by default
Change anything. Undo everything.
“Keep this?” on every change
Resolution, refresh rate, rotation, mirroring, virtual screens: each change asks to be kept, and goes back by itself after 15 seconds. A black screen fixes itself. Your last display is never turned off.
Restore everything
Restore everything (⌃⌥⌘R, or the menu item) removes virtual displays, turns every display back on, clears software dimming and reverts the last mode change. It also resets colour and stops every stream.
- No analytics
- No account
- History stays on your Mac
- Local control is opt-in
Private by design
The only internet traffic is the licence check and the update check. Picture in picture asks for Screen Recording only when you first use it, and captured frames never leave your Mac.
Two apps. One key. One timeline.
With iKnowMyMac, display drops and USB reconnects show up side by side, so a dock reconnecting right before your monitor dropped stands out.
Pricing
Pay once. No subscription.
iKnowMyDisplay
Launch price$4.99for 1 Mac
Launch price · 100 of 100 Macs left
- Every feature
- Licences for 1, 2 or 5 Macs
- Personal and business use
- Updates for this major version
- No account, no subscription
- 14-day refund, no questions
iKnow Suite
From$7.99
$7.99 for 1 Mac, $14.99 for 2 Macs, $39.99 for 5 Macs. iKnowMyDisplay and iKnowMyMac, unlocked by one key.
Own iKnowMyMac? Get iKnowMyDisplay from $2.99 with your licence key.
Questions
Good to know
Which Macs does it work on?
Macs with Apple silicon (M1 or later) on macOS 15 Sequoia or later. Intel Macs aren't supported.
Will it fix my 30 Hz or blurry monitor?
It tells you why it happens and what to change, like moving the cable to a different port or picking a sharp size. When the limit is the hub or cable, the fix is a different hub or cable, and the app tells you which.
Can it break my display setup?
Every change that could leave you with a black or wrong screen asks “Keep this?” and goes back by itself after 15 seconds. ⌃⌥⌘R restores everything from anywhere.
Does my monitor need anything special?
No. Hardware brightness, volume and input need a monitor that accepts them over its cable (DDC); some monitors and docks don't, and the app says so. Software dimming works on every display.
What does Peak brightness do?
On a MacBook Pro with a Liquid Retina XDR display, and other displays macOS gives HDR headroom, it lets everything use the brightness macOS normally keeps for HDR video. It uses more battery and heat, so it turns off below 20% battery and pauses when the Mac is hot. ⌃⌥⌘R turns it off.
Is there a trial?
There's a 14-day refund with no questions instead. The compatibility checker shows what to expect before you buy.
What leaves my Mac?
Only the licence check and the update check. No analytics, no account. Local HTTP control and TV control are off until you turn them on, and stay on your network.
Know your displays.
Apple silicon · macOS 15 Sequoia or later. One-time purchase. 14-day refund.