Twin Finder

2UP is a native macOS app built from the familiar behaviours of Finder—not a terminal file manager with a graphical coat of paint.

• Finder foundations: list and icon views, Quick Look, tags and comments, Get Info, Open With, Trash, aliases, file extensions, mounted volumes, and standard Mac selection
• Two panes, or a focused single-pane layout that collapses automatically below a width you choose or capture from the current window
• Optional compact toolbar and a show/hide tab bar that reclaim room for files
• Independent folder, history, sorting, filtering, selection, and view for each side
• Finder-style handling of apps, bundles, and other packages
• Copy the active folder to the other side, swap both folders, or reveal a selection opposite
• Synchronise navigation, column widths, and visible columns when you want the panes to move together
• Each panel watches its folder and updates live, with manual refresh when you want it
• Drag and drop between panels and to and from Finder, or drop straight onto a folder row to file items inside it
• Folder rows that are symlinks or aliases resolve to their target, so a disk image’s “drag the app to Applications” shortcut works
• Mounted volumes and network shares appear and disappear as they come and go, and a pane inside an ejected volume moves somewhere still readable
• Eject or unmount a selected volume from its context menu, the Volumes menu, or the File menu—never the system drive

Tabs, When You Want Them

• Opt-in per-pane tabs—each panel holds several folders and switches between them (off by default)
• Every tab keeps its own folder, selection, view, sort, columns, and back/forward history
• New, close, close-others, close-to-the-right, close-all, cycle by keyboard, reorder by dragging, or merge into the previous tab
• Pin a tab to keep it at the head of the strip and locked against closing—every close command steps over it until you unpin
• ⌘W steps past a pinned tab rather than closing it, so a held ⌘W clears the unpinned tabs while the pinned ones slide by
• Unpin from the chip, the context menu, or by dragging the tab out past the pinned block; drag one in to pin it
• Sort Tabs by Name, with the pinned and unpinned runs sorted independently so the pinned block stays put
• Reopen Closed Tab restores one of the last ten from either pane to its old position, folder, history, and selection intact—or pick any of the ten from Recently Closed Tabs
• Rename a tab to something of your own—it survives a merge, and resets to the folder’s name on request
• Drag a tab to the other pane to move it, or hold Option to copy it; a pinned tab arrives pinned
• Drop files onto a tab to move or copy them into that tab’s folder, with the chip highlighted like a folder row—and the tab you’re looking at left alone
• Drag a tab out of the window to hand its folder to another app: the chip drags exactly like the folder does from Finder, onto an editor, Terminal, or the Dock
• Right-click a tab to see its expanded path and click to copy it, alongside pin, sort, close, move, and merge commands
• New tabs open beside the current one rather than at the far end of the strip, and Open in New Tab on a multi-item selection opens every folder you picked
• Tabs showing same-named folders are told apart by the nearest ancestor folder that differs
• New tabs inherit the view options of the tab they were opened from
• Tab bar appears automatically when a pane has more than one tab, or always via a setting; tabs scroll, with edge controls that reveal and jump to hidden tabs
• Open tabs, their order, their pinned state, and the active tab restore on relaunch
• Optionally adopt Finder windows as new tabs, reusing a tab already showing the folder

Move at Keyboard Speed

• Switch panes, open folders, go back or forward, jump to a path, and extend selections without reaching for the pointer
• Editable path bar with breadcrumb segments that completes directories as you type
• Right-click any breadcrumb segment to act on that ancestor folder—open it here, in a new tab, or in the other pane, open Terminal there, get info, copy it or its path, reveal it in Finder, or move it to the Trash
• Go to Folder by typed path, plus one-key jumps to Home, Desktop, Documents, Downloads, Applications, Utilities, and the filesystem root
• Follow symbolic links to their targets
• Bookmarks (⌘1–⌘9), frequently visited folders, mounted volumes, and clearable folder history keep regular destinations close
• Select by file extension or with * and ? filename masks, and invert selections
• Filter or select by typing, case-sensitively if you like, or go recursive to search the whole subtree—matches stream into the pane as they’re found
• Search inside files from the same filter bar: Spotlight-backed results and a bounded local fallback appear in place with relative paths, live progress, and a final match count
• Turn a filter into a persistent colored highlight rule that follows files from folder to folder
• Quick Palette fuzzy-searches commands, bookmarks, folders, volumes, and history from one place—including Filter Files and Search Contents—and remembers your recent searches

Browse Your Way

• Sort by name, extension, kind, size, or date, with folders-first and natural numeric ordering
• Every tab remembers its sort across relaunches, and brand-new tabs and panes start from a default sort you choose
• Light, Dark, or system appearance, and ISO or system date format
• Resizable, configurable list columns backed by a native table
• Mounted volumes show their own drive artwork, including a disk image’s custom icon
• Keyboard navigation keeps the cursor on screen in both views, scrolling the minimum needed—just like Finder
• Adjustable list text size and an icon-view zoom that snaps to whole-column boundaries—one more or one fewer icon per row
• Show or hide hidden files, with a visible/hidden breakdown
• Listings keep going past folders you aren’t allowed to read, instead of burying every readable row under a permission error
• Always show file extensions or respect Finder’s per-file setting
• Status bar with a Finder-style item, selection, filter, or content-search count and the volume’s free space—one figure per volume, so two panes on the same disk always agree

Serious File Operations

• Create files and folders in either pane; open, rename, duplicate, copy, move, and trash them; or gather a selection into a new folder
• Renaming preselects the name up to the last dot, so typing replaces the stem and leaves the extension alone—where Finder stops at the first dot and hands you half a screenshot’s name—with optional Finder-style single-click rename
• Opening a multi-item selection opens all of it: every document launches, the first folder fills the current tab, and the rest open behind it
• Batch rename with find/replace, prefix, suffix, case transforms, and sequential numbering—after the name, before it, or renumbering what’s already there—with a live preview
• Cut, copy, and paste, or Copy As and Move As with a new destination name or path
• Conflict handling with replace, keep both, or skip choices, and an optional warning before changing a file extension
• Hold Option in the menus for alternate commands: Get Info becomes Show Inspector, Rename becomes Batch Rename, Copy becomes Copy as Pathname, Move To becomes Copy To, Make Symlink becomes Make Hard Link, and Move to Other Pane becomes Copy to Other Pane
• Move to Trash with Put Back, Empty Trash, or optional immediate deletion
• Operations that need elevated rights hand off to Finder for the usual Touch ID or password prompt, rather than stopping at a permission error
• Undo and redo for supported filesystem changes, with progress for long-running operations
• Create ZIP archives—or Compress To a name and destination of your choosing—and expand archives with your preferred app
• Make Finder aliases, symbolic links, and hard links—and inspect or edit a symlink’s target

Understand Every File

• Preview with Quick Look, rotate images inside the preview, or open Finder’s Get Info
• 2UP’s own floating inspector tracking the selection: kind, size, location, dates, permissions, tags, alias targets, image or media metadata, and a kind breakdown for multiple selections
• Edit octal POSIX permissions and extended attributes, with a hex view for binary values
• View and edit Finder tags and comments
• Calculate folder sizes—for a selection or every visible folder, remembered per folder—copy paths and filenames, and reveal items in Finder
• Folder sizes stay honest when files change deep inside a folder, not only when its own contents change
• Open With and Always Open With to choose the app for a file
• Every context-menu action also lives in the menu bar, so any command can take a keyboard shortcut

Built-in Image, PDF & Media Tools

• Convert images between common formats, replacing the original or keeping a converted copy
• Scale, rotate, and flip, with smooth or nearest-neighbour resampling for pixel art
• Strip EXIF and GPS metadata, or remove backgrounds
• Recognise text and read barcode and QR payloads
• Extract every frame of an animated GIF or APNG as PNGs
• Combine images into a PDF, and merge or split PDFs
• Extract audio, or convert it to WAV, AIFF, CAF, M4A, or FLAC
• Save a movie poster frame, or build a contact sheet of evenly-spaced video frames
• Extract evenly-spaced video frames as PNGs
• Transcode video to 1080p, 720p, 480p, or half size, in H.264 or HEVC, or convert it to an animated GIF or APNG
• Copy SHA-256 or MD5 checksums to the clipboard, or write them straight into a file’s Finder comment
• All without leaving the file manager

Works with Your Mac

• Adopt your top Finder windows as 2UP’s panes, preserving complete selections—including hidden and newly revealed items—during the hand-off
• Optionally turn extra windows into bookmarks, or adopt new Finder windows automatically
• Optionally close Finder windows after adoption, or bring 2UP forward when Finder takes focus
• Automatic adoption recovers when Finder is launching or busy
• Act on selected files with any installed macOS Service, Automator, or Shortcuts workflow
• Offer 2UP’s own Compress, Recognize Text, and Copy SHA-256 as system Services in other apps and Finder
• Configure your preferred editor, image app, miscellaneous app, and unarchiver
• Customise the file context menu, run your own scripts, or open Terminal at the active folder
• Configure event-driven Finder adoption through macOS Accessibility integration

Good Citizen

• Native SwiftUI app
• No third-party frameworks, accounts, subscriptions, analytics, or advertising
• Runs fully sandboxed, with app-scoped security bookmarks and guided, revocable Home-folder access
• Dropping items into a folder outside the granted area asks for access to it rather than failing silently
• Accurate Full Disk Access and Accessibility status checks with direct links to the right macOS settings

Optimised

• Only 2 MB app download size
• Only 100 MB base memory footprint

How 2UP Compares With The Competition

“✓” means the feature is presented as built in by the app’s official documentation.
“–” means it isn’t documented there; external tools or plugins may still provide it.