The Space Helper

Turn on spacebar’s Space helper and Space in Finder opens any file in spacebar

Optional, off until you turn it on
Asks for Accessibility
Free and open source
macOS 13+

The helper watches for Space in Finder and reads which file is selected. It never opens a file.

The viewer renders the file, with the same code and the same sandbox as spacebar’s Quick Look extension.

How Space reaches spacebar with the helper on. Diagram drawn in HTML.

orbitTry it: press space

Select a file and press space to preview it; space or esc closes it. On a phone, tap a file twice.

Try it: the demo folder in a Finder list. With the Space helper on, Space opens the file in spacebar’s own preview page, running in your browser.

Quick Look never hands an app’s extension the types Apple previews itself. The optional Space helper closes that gap: Space in Finder opens any file in spacebar’s window, its folder in the sidebar.

What The Space Helper Does

PDFsDrawn by PDFKit, with the page count and ⌘F
PhotosHEIC, camera RAW and Photoshop, with pinch to zoom
Video and audioIn the native player
CSV and textTables of up to 50,000 rows; text in UTF-8 or a legacy encoding, rich text, HTML
Office, iWork, fonts, 3DApple’s preview in spacebar’s window (single-file iWork)
Installers and binaries.pkg, .exe and .dylib get an info card

Apps, packages and .rtfd documents stay with Apple’s Quick Look, ⌘Y still opens Apple’s, and while a password field or another app has secure input on, Space opens Apple’s Quick Look.

Full list: Every file type. What changes: Quick Look replacement.

Turn It On

Install spacebar 0.3 or later.
Turn on Use spacebar for every file in the welcome window or Settings.
Turn on spacebar Helper in System Settings › Privacy & Security › Accessibility when macOS asks.
Select any file in Finder and press Space.

The helper runs at login, listed as spacebar under Allow in the Background in Login Items & Extensions. Settings shows its state.

If Space still opens Apple’s Quick Look, spacebar’s first preview there says why in one line, and a click opens Settings.

Windows And Keys

`Esc` `⌘W` `⌘.`	In Finder, close a window you haven’t clicked into
`⌘W`	Close the window you’re in; there, Esc does nothing
`Space`	On a file that’s already open, bring its window forward
`↑` `↓`	The next file in the sidebar
`⌘F` `⌥⌘F`	Find in the file; the sidebar’s filter
`⌘C`	With nothing selected, copy the file and its text, as Finder does
`⌘+` `⌘−` `⌘0`	Zoom a photo, as do pinch and a double-click
`Return`	Open a picture from a folder’s grid of thumbnails

"sidebarKeys": false in settings.json moves the arrows through Finder’s selection instead.
Select several files first and the sidebar shows just those, even from several folders, with “2 of 5” in the toolbar.
It stays open when you switch apps, like a Finder window: resize it, take it full screen or minimize it. It’s in the Dock and ⌘Tab.
Space on another file opens another window. The newest one follows Finder’s arrow keys until you click into it.
Drag a file out of the sidebar, a result, the grid or the toolbar’s kind, and Finder copies it. The chevron beside Open is Open With, empty for scripts, apps and files like .env.

Why It Needs Accessibility

Quick Look gives extensions no key events, so the helper watches the keyboard with an event tap and reads Finder’s selection. macOS allows both only with Accessibility.

Accessibility is powerful, so spacebar gives it to as little code as possible.

What It Can And Can’t See

The helper can:

See key events go by, as anything with Accessibility can. It acts only on a plain Space in Finder, and while the newest window follows Finder, on Esc, ⌘W and ⌘. there, which close it. Arrow keys stay with Finder.
Read Finder’s focus and which files are selected.

It doesn’t:

Record, store or send what you type. Other keys pass straight through; it forwards only key names, such as “down”, never text.
Open or read any file. It has no file-reading, web view or network code.
Act in a rename, a search field, another app, over Apple’s Quick Look or under secure input.
Talk to anything but spacebar’s own apps, signed by the same certificate.

How It’s Built

HTML opened with Space never runs its scriptsWhatever your settings say.
Keys only on screenFinder’s keys go back the moment another app comes forward.

The helper has no entitlements and runs under the hardened runtime; any error hands the key back to Finder. The viewer quits after 30 minutes closed. The trade-off: the helper sees every key event while it runs, so it’s kept small and open source. SECURITY.md (opens in a new tab) covers the risks that remain.

How Fast It Is

Space to the helper’s decision: ~8 ms
Median, Space to on screen: 42 ms
An arrow to the next file: 21 ms

About 8 ms of a median of 42 ms is the helper’s. The first file after the viewer starts takes about 130 ms; a Space unanswered in 150 ms goes back to Finder. One Apple-silicon Mac, macOS 15.4.1, files warm, in the Space window, for Markdown, text, images and PDFs.

Turn It Off

Turn off Use spacebar for every file. The helper leaves Login Items and Space goes back to Apple for the types it keeps. To revoke the permission too, remove spacebar Helper in Privacy & Security › Accessibility; uninstalling does it for you.

Without The Helper

spacebar is a Quick Look extension for Markdown, folders, code, config, plists, logs, archives, .dmg and files with no extension. The rest keep Apple’s preview and open from spacebar’s sidebar: Quick Look a whole folder.

Install It

Download for Mac

Or paste this in Terminal

$ curl -fsSL https://spacebar.patebryant.com/install.sh | sh

The script downloads the latest notarized release from GitHub, checks its SHA-256 and installs to ~/Applications, no sudo. Read the script.

Questions? Help covers a helper that isn’t opening files, and the FAQ covers Accessibility and your keystrokes.