Dimit

Free and open source under the MIT licence. Dimit is a native macOS menu-bar app that warms your screen down to pure red, dims it in software, and offers a PWM-Safe mode that holds supported backlights at 100%. Two sliders, three presets, one ON/OFF button. English, Uzbek (Latin), and Russian.

Download from GitHub Releases, or build it yourself. Every feature is free: no accounts, licence keys, activation, or telemetry.

• Warmth from 6500K to “0K”. The display's gamma tables produce the tint; “0K” is a name for pure red, not a physical temperature.
• Software brightness down to 10%, with settings applied across connected displays.
• PWM-Safe mode pins a supported hardware backlight at 100% and uses software dimming. Whether that eliminates pulsing depends on the panel; Dimit does not measure flicker. Third-party DDC/CI control is experimental and off by default.
• Sunset/sunrise or fixed-time schedules, calculated locally from a bundled city list or an optional device location, plus presets and global shortcuts.
• Restore Colours is available from the menu. OFF, quit, signal handlers, and launch restore the gamma tables; restoration on relaunch also handles a force-killed process.

The app makes no network requests unless you enable automatic updates or explicitly choose Check for Updates…. Sparkle uses the GitHub Pages appcast and release assets for updates. Automatic checks are off by default. No Accessibility, Screen Recording, or administrator permission is required; Location is requested only when you press Use my location.

How to install

Requires macOS 13 or later, on Apple silicon or Intel; the release build is universal. This is the deployment target, not a claim that every version has been tested. See the systems and limitations below.

1. Download the DMG attached to a GitHub Release.

2. Open it and drag Dimit.app into Applications.

3. The current v0.6 beta is ad-hoc signed and not notarized. After downloading it from this repository, remove its quarantine flag in Terminal:

   xattr -dr com.apple.quarantine /Applications/Dimit.app
   

4. Open Dimit from Applications. Its icon appears in the menu bar, with no Dock icon.

Follow the signing status in each release's notes; a future notarized release will not need the quarantine step. Quit an older running copy before installing an update. Full packaging instructions are in docs/RELEASE.md.

Tested systems

These are the reports we have, including failures. See hardware QA for the checks, measurements, and remaining gaps.

macOS 13 and 14, Intel hardware, and other display combinations still need reports.

Known limitations

• macOS 26 colour bug. On some Macs, macOS 26 stores a gamma change and reports success while the screen keeps its normal colours. Tracked Apple reports are FB18559786, FB19136488, and FB22273730; the evidence and Apple's forum threads are in CLAUDE.md §3.3 and QA. Turning off automatic brightness in System Settings → Displays helps on many of them. Every Mac we have been able to test on works, so this is Apple's evidence rather than ours. Dimit has no tint fallback: where the bug does hit, dimming and PWM-Safe still work but colours do not change, and pinning the backlight without working gamma dimming makes the screen brighter.
• Capture with other recorders. Screenshots, QuickTime recordings and Zoom shares show normal colours on the Macs tested; screenshots were also checked below 30%, where dimming uses an overlay window, and the overlay does not appear in them. sharingType = .none is what excludes it, and Apple describes that as legacy with no guarantee against ScreenCaptureKit — OBS-class recorders, and recordings or shares taken below 30%, are still untested.
• Experimental DDC. Off by default, limited to one external monitor, and no successful third-party backlight pin has been confirmed. A DDC transaction can briefly block the UI; the Mi Monitor returned error frames in hardware testing.
• Coverage and polish. Other hardware and macOS versions, full capture coverage, keyboard focus, VoiceOver, and fluent Uzbek/Russian review still need testing. Pending checks remain visible in QA.

How to build

Install Xcode 26 or newer and select it with xcode-select. The project uses a Swift 6 toolchain in Swift 5 language mode. Bootstrap installs XcodeGen via Homebrew if it is missing, then generates the project:

git clone https://github.com/azakapro/dimit.git
cd dimit
scripts/bootstrap.sh
xcodebuild test -project Dimit.xcodeproj -scheme Dimit -destination 'platform=macOS'
scripts/build.sh

Quit any running Dimit before the last command: it builds a universal release app and verifies that the artifact launches and exits cleanly. The result is build/release/Dimit.app; scripts/build_dmg.sh packages an ad-hoc beta DMG. For local debugging, open Dimit.xcodeproj and run the Dimit scheme.

Dimit.xcodeproj is generated and gitignored: edit project.yml, then re-run bootstrap. The two existing Swift packages are pinned: KeyboardShortcuts and Sparkle.

Read CONTRIBUTING.md, the engineering spec, and the architecture before changing display code. On a new macOS build, run swift scripts/gamma_spike.swift before trusting gamma results. The plan records cycles C0–C7 and PR requirements.

How to report a bug

Open a bug report with the app version, Mac model, macOS version, display and connection, steps, and expected versus actual behaviour. Do not paste serial numbers or precise personal coordinates. Review copied diagnostics and screenshots before sharing. For colour issues, describe the physical screen; screenshots cannot prove a gamma tint. The tester checklist lists useful hardware checks.

Support

Dimit is free and always will be. If it earned a place in your menu bar, you can buy me a coffee — entirely optional, and it unlocks nothing, because there is nothing to unlock.

Licence

MIT · Copyright © 2026 Azizullo Temirov.