Arc Spaces & Sidebar Shortcuts
Spaces are the feature Arc is built around — named, themed workspaces that each hold their own set of tabs — and the sidebar is where they live. Between them they replace the tab strip, the bookmarks bar and the window-per-project habit that other browsers push you toward.
| Action | Windows | Mac | Description |
|---|---|---|---|
| Show / hide the sidebar | Ctrl+S | Cmd+S | Collapses the sidebar out of view and brings it back. Because Arc has no horizontal tab strip, hiding the sidebar leaves the page genuinely alone on screen — this is Arc's closest equivalent to a reading mode, and it is a toggle rather than an auto-hide. |
| Switch to the next Space | Ctrl+Alt+Right | Cmd+Option+Right | Moves one Space to the right in the Space switcher. The sidebar slides rather than cutting, which is deliberate — the animation is what tells you which direction you moved, since Spaces have no persistent index shown on screen. |
| Switch to the previous Space | Ctrl+Alt+Left | Cmd+Option+Left | Moves one Space to the left. Paired with the next-Space binding this is the fastest way to move between two adjacent Spaces, which is why people who use Spaces heavily tend to order them by how often they switch between them. |
| Jump directly to a numbered Space | Ctrl+1 through Ctrl+9 | Ctrl+1 through Ctrl+9 | Goes straight to a Space by position rather than stepping through them. Note this is Ctrl, not Cmd, on macOS as well — Cmd with a number selects an item within the current sidebar instead, and the two are easy to confuse. |
| Go to a numbered sidebar item | Ctrl+1 through Ctrl+9 | Cmd+1 through Cmd+9 | Selects a pinned item by its position in the current Space's sidebar. This is the binding most Chrome users expect to switch tabs, and in Arc it addresses pinned items in the sidebar rather than open tabs in a strip. |
| Create a new Space | No default — click + in the Space switcher | No default — click + in the Space switcher | Arc ships no keyboard binding for creating a Space. That is a defensible omission — Spaces are meant to be long-lived containers you make a handful of times, not something created in the flow of browsing — but it surprises people who expect symmetry with the switching shortcuts. |
Switching Spaces is Cmd+Option with the left and right arrows, and the direction of the sidebar's slide is the only indicator of which way you moved. That sounds like a design flourish and functions as real feedback: Spaces carry no visible index, so the animation is what tells you the switch happened and in which direction. People who use Spaces heavily tend to order them by adjacency — the two they move between most often placed next to each other — because a single arrow press is meaningfully faster than two.
Jumping directly to a Space by position is Ctrl with a number, and this is where Arc trips almost everyone at least once. On macOS the binding is Ctrl, not Cmd, even though Cmd is the modifier for essentially every other application command in the browser. Cmd with a number does something related but different: it selects a pinned item in the current Space's sidebar. Two bindings, one modifier apart, both addressing 'the nth thing' but in different scopes. When a number key jumps to a pinned tab rather than the Space you expected, the modifier is the explanation every time.
The sidebar toggle on Cmd+S is more consequential in Arc than a sidebar toggle would be elsewhere, because Arc has no horizontal tab strip to fall back on. Hiding the sidebar leaves the page genuinely alone on screen with no browser interface at all — the closest thing Arc offers to a reading mode. It is a toggle rather than an auto-hide, so the sidebar stays gone until you bring it back, which is what makes it usable for sustained reading rather than merely a way to reclaim a few pixels.
Creating a Space has no keyboard binding at all, which looks like an oversight next to the switching shortcuts but is arguably correct. Spaces are meant to be durable containers — one for work, one for a specific project, one for personal browsing — created a handful of times and then lived in for months. That is not an action that belongs in the flow of browsing, and giving it a key would invite the proliferation the feature is designed to prevent. Clicking the plus in the Space switcher is the only route, and in practice most people use it a few times and then not again.
What makes the sidebar work as an organising surface rather than just a vertical tab list is the split between pinned and unpinned items. Pinned items, added with Cmd+D, persist indefinitely and survive every form of tidying. Unpinned tabs are treated as temporary and get cleared automatically on a timer. That division is the engine behind most of Arc's tab behaviour, and it is why the browser can archive on Cmd+W without anyone objecting — the things that mattered were pinned, and the things that were not pinned were, by the design's own definition, not worth keeping. Understanding that division makes the rest of Arc's keymap follow logically rather than needing to be memorised piece by piece.
One consequence of Spaces being genuinely separate is that the same site can be open in two of them at once without conflict, holding different pages and different scroll positions. That is useful in ways tab groups are not — a documentation site open in a work Space and again in a side-project Space are two independent things rather than one tab you keep navigating back and forth. It also means a Space can be left mid-task and returned to intact, which is closer to how a desktop workspace behaves than how browser tabs traditionally do.
The theme colour attached to each Space is doing more work than decoration. With no on-screen index and no label visible while you browse, colour is the only persistent signal of which Space you are in. That argues for choosing genuinely distinct colours rather than tasteful variations on one palette — three shades of blue look considered and defeat the purpose entirely. People who use four or more Spaces almost always end up recolouring them at some point for exactly this reason.
A final practical point: moving a tab between Spaces has no keyboard binding either. Dragging it onto the target Space's icon in the switcher is the supported route, with a move command available through the Command Bar as an alternative. This is the same principle as Space creation — Arc assigns keys to the actions you take constantly and leaves the occasional structural rearrangement to the mouse, on the reasonable assumption that reorganising your workspace is not something you do mid-sentence.