GitHub - lucianmarin/monochrome: Mobile browser for macOS.

Monochrome is a lightweight, native mobile web browser for macOS built with AppKit and WebKit (WKWebView). It renders websites using an iPhone Safari user agent inside compact, mobile-sized macOS windows—ideal for distraction-free browsing, side-by-side reference windows, and testing responsive mobile layouts.

Features

Mobile Viewport & User Agent: Sends an iOS Safari (iPhone) user agent so websites serve their fast, clean mobile layouts on macOS.
iPhone Viewport Presets: Quickly switch between 6 standard iPhone logical viewport dimensions (⌘1–⌘6), defaulting to SE (375 × 667) with resizable bounds from 320 × 480 up to 440 × 956.
Compact Expanded Toolbar: Native macOS toolbar displaying Back, Reload / Stop, Home, and the Address field by default, with optional customizable items (Forward, New, Loading indicator, spaces).
Toggleable Status Bar: Optional bottom status bar (hidden by default, toggleable from View → Show Status Bar or ⌘/) showing the downloading page size and total site size (KB / MB) on the left and live window dimensions (width × height px) on the right.
LZFSE-Compressed Browsing History: Stores up to 1,000 normalized, deduplicated URLs in most-recently-used (MRU) order inside UserDefaults using Apple's LZFSE compression—requiring zero external database files.
Inline Address Bar Autocomplete: Suggests and highlights matching URL suffixes from browsing history as you type, handling optional http(s):// and www. prefixes and prioritizing clean paths before query strings.
Smart Address & Search Bar: Navigates directly to URLs or domains and routes search queries through a configurable search engine (defaulting to DuckDuckGo: https://duckduckgo.com/?q=).
Multi-Window & Tabbed Browsing: Built on NSDocument to support multiple independent browser windows and native macOS window tabs (⌘N, ⌘T).
Trackpad Gestures & Zoom: Supports two-finger swipe back/forward navigation gestures and pinch-to-zoom magnification.

Window Size Presets

Accessible from the View menu or via keyboard shortcuts:

Preset	Width	Height	Shortcut
5s (`320px`)	`320px`	`568px`	`⌘1`
Mini (`360px`)	`360px`	`780px`	`⌘2`
SE (`375px`) (Default)	`375px`	`667px`	`⌘3`
e (`390px`)	`390px`	`844px`	`⌘4`
Pro (`402px`)	`402px`	`874px`	`⌘5`
Max (`440px`)	`440px`	`956px`	`⌘6`

Keyboard Shortcuts

Action	Shortcut
New Window / Tab	`⌘N` / `⌘T`
Open Location (Focus Address Bar)	`⌘L`
Reload Page	`⌘R`
Reload From Origin	`⇧⌘R`
Stop Loading	`⌘.`
Back	`⌘[`
Forward	`⌘]`
Home	`⇧⌘H`
Find on Page	`⌘F`
Preferences	`⌘,`
Customize Toolbar	`⌥⌘T`
Show / Hide Status Bar	`⌘/`
Resize Window (`5s` – `Max`)	`⌘1` – `⌘6`

Preferences & Defaults

Open Monochrome → Preferences… (⌘,) to choose a homepage and search engine preset or configure custom URLs:

Brave: https://search.brave.com/ | https://search.brave.com/search?q=
DuckDuckGo (Default): https://duckduckgo.com/ | https://duckduckgo.com/?q=
Google: https://www.google.com/ | https://www.google.com/search?q=
Custom: Custom Homepage and Search Engine URL fields (shown when Custom is selected)

Settings and LZFSE-compressed browsing history (BrowsingHistory) are stored in UserDefaults under com.lucianmarin.Monochrome.

Project Structure

Monochrome/AppDelegate.swift — Application lifecycle and default Homepage / SearchEngine registration.
Monochrome/Document.swift — Browser window controller (NSDocument), programmatic NSToolbarDelegate, WKNavigationDelegate / WKUIDelegate, window size presets, BrowsingHistory LZFSE store, and NSTextFieldDelegate inline autocomplete.
Monochrome/Preferences.swift & Monochrome/Preferences.xib — Preferences window controller bound to NSUserDefaultsController.
Monochrome/Base.lproj/Document.xib — Browser window nib and WKWebView configuration.
Monochrome/Base.lproj/MainMenu.xib — Application menu bar and keyboard shortcuts.

Building & Running

Open Monochrome.xcodeproj in Xcode (Swift 5, macOS SDK).
Select the Monochrome scheme and press Run (⌘R), or build from the command line: