How to view two files side by side on a Mac
You can do this with Note My — here is how to set Multi View up, how to arrange the panes the way you read, and the point where Compare takes over.
You have a reference open — a schema, a config file, a log, a piece of documentation — and you need it visible while you type in a different file. Switching tabs back and forth loses your place every time. What you want is both files on screen at once, in one window, with each one scrollable on its own.
Note My does this with Multi View. It takes about a second to set up. The part worth reading first is what the panes actually contain, because that is what makes the arrangement so quick to set up and so easy to change.
What Multi View actually does
Multi View gives each open tab its own pane, side by side, each pane aligned under its tab. Two tabs give you two panes. Five tabs give you five. There is nothing separate to set up: the files you have open are the files you see, so you choose your side-by-side arrangement by choosing what to open and what to close.
The toolbar button's own description is exact: "Show every tab in its own side-by-side pane." Its companion, Single View, "collapse[s] back to a single pane showing the active tab."
Each pane is a full editor. You can type in any of them, and the caret follows the pane you click into. Scrolling one pane does not move the others — they are independent views of independent documents.
One pane per document
Every pane holds a different tab, and that is what makes the layout so easy to reason about: the row of panes is the row of tabs, laid out flat. Put a schema beside the file that consumes it, a log beside the script that wrote it, or a translation beside the original, and both stay on screen for as long as you want them there.
Because each pane is a document in its own right, it carries its own caret, its own selection and its own undo history. Edit in one, read in another, and come back to the first with everything where you left it. Nothing you do to the layout touches the text.
To move a long way inside one file without losing your place, use ⌘L for Go to Line, and bookmarks — ⌘F2 to toggle one, F2 and ⇧F2 to step between them.
Put two files side by side
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Open both files first
Press ⌘O and select them — you can pick several at once, and each arrives in its own tab. You can also drag files from the Finder straight onto the tab bar, or right-click a file in the Finder and choose Note My ▸ Open. From the Finder menu, Open in Background loads a file into a tab without pulling you away from what you are doing.
Open everything you want to see before the next step. You get one pane per tab that is open when you press the button.
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Press Multi View in the toolbar
It is the split-rectangle button in the layout group. The panes slide in, one per open tab, in tab order.
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Click into the pane you want to work in
Typing goes to whichever pane holds the caret. The other panes stay exactly where you left them — same scroll position, same selection.
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Collapse back with Single View
Press Single View — the button beside it — and the other panes slide away, leaving the tab you had selected. Nothing is closed, and nothing is saved or discarded; you are only changing the layout.
Rearranging the panes
Panes appear in tab order, which is not always the order you want to read in. Right-click inside a pane and you get Move Pane Left and Move Pane Right. Each one shifts that pane one position along the row.
Two things hold a pane where it is:
- It is already at the edge. The leftmost pane is as far left as the row goes, so a move beyond it sounds a beep and leaves your arrangement untouched.
- A tab is pinned. Pinning steadies the whole row: a pinned tab anywhere in the window keeps the panes in the order you settled on, which is exactly what you want once the layout is right. Unpin from the tab's right-click menu when you want to rearrange, then pin again afterwards.
The other way to change the order is to reorder the tabs themselves: drag a tab along the bar, and its pane follows.
What each pane keeps to itself
Almost everything you set or move in a pane stays with that pane's own file. One setting is deliberately different, and it is worth knowing which before you reach for it.
| Behaviour | Scope |
|---|---|
| Scroll position, caret, selection | Per pane |
| Syntax colouring | Per document — each pane is coloured for its own language |
| Undo history | Per document |
| Word wrap | One global setting, applied to every pane — on screen or not |
That last row is the one to remember. The Wrap toggle in the toolbar is one setting shared by the whole app, so turning wrapping on for a narrow pane turns it on everywhere at once. It is on by default, and it lives on the toolbar and in the View menu — one press away from the pane you are reading, whichever pane that is.
Narrow panes are where wrapping earns its keep. Three or four panes across a laptop display leaves each one very narrow, and without wrapping every long line becomes a horizontal scroll.
Colouring, by contrast, is settled per file. Put a configuration file beside a shell script and each is coloured for what it is — our advanced language identifier gives every pane the colouring that suits the file sitting in it, so there is nothing to choose pane by pane. It all happens on your Mac: nothing is uploaded, and there is no account.
Side by side, or Compare?
They are different jobs and it is worth being deliberate about which one you are doing.
| You want to… | Use |
|---|---|
| Read one file while editing another | Multi View |
| Keep three or four related files visible at once | Multi View |
| See exactly which lines differ between two versions | Compare |
| Scroll two files in step | Compare, holding ⇧ |
Compare Files… lives on the toolbar's Compare menu. It opens a pairing canvas — two scrolling columns of cards, one card per open tab — where you pick a document on each side and press Compare. Open at least two documents and you can pair any two of them: a comparison is a focused pair, one document on the left and one on the right, so the difference you are looking for has nowhere to hide. With exactly two tabs open, Quick Compare pairs them immediately; with more, it asks you to click the partner tab, so the pair is a single click away.
In compare mode our comparison view tints the differing lines in place and lists them in a bottom inspector — "N differing lines", with a table of document, line and content that flashes the line in both panes when you click a row. Work down the rows rather than hunting for tints by eye. It also carries a Reveal Invisibles toggle, which puts our hidden-character scanner to work on both sides, so a difference that is only a tab standing in for spaces stops being invisible, and an Exit Compare button. ⎋ leaves compare mode. None of the colouring is written into either file.
Mirrored scrolling is yours by the moment. In compare mode, hold ⇧ and both sides move in step, so matching sections stay level with each other. A heads-up display says so — "Parallel scroll — Hold Shift to mirror scroll" — and changes to "Mirroring scroll" while the key is down. Release the key and each side scrolls on its own again, so you can run one file down a long stretch without dragging the other along with it.
A working setup
The arrangement that holds up over a long session: the file you are changing on the left, the reference on the right, and nothing else open.
A few small things make it stick. Pin the reference tab from its right-click menu — pinned tabs refuse to close, so a stray ⌘W cannot take your specification away with it. Pinning also settles the pane order, so arrange the row first and pin once it looks right. Widen the tabs by dragging a tab's right edge if the filenames are truncating — worth doing when two filenames share a long prefix. And read the tab markers correctly: a leading * on the title means unsaved edits, while an orange dot means the file changed on disk underneath you — a different problem with a different fix.
Scroll the reference to the section you need once. Each pane keeps its own place, so it will still be there an hour later.
Troubleshooting
Adding a file once the panes are showing
Press Single View and then Multi View again, and the row rebuilds around everything you now have open — one pane per tab, the new file included. It is the same two presses whether you have added one file or five, and it takes about a second.
Fewer panes than I left after a relaunch
Your tabs all come back after a relaunch. If the row returns with fewer panes than you had, press Multi View again and it rebuilds in full, one pane per open tab. Everything is still there in the meantime: the documents are open, each one exactly as you left it, unsaved text included.
A pane will not move left
Two things settle it. If the pane is already the leftmost one, that is as far left as the row goes — move the pane beside it across with Move Pane Right instead, and you get the same order from the other direction. If a tab anywhere in the window is pinned, the row is being held steady on purpose: unpin it from the tab's right-click menu, make the move, then pin it again once the arrangement looks right.
Single View left two documents on screen
Press Multi View and then Single View again, and the window collapses to the tab you had selected. Nothing is at stake while it happens: both documents are intact, neither is closed, and neither is written to. Leaving compare mode with ⎋ works as it always does.
Every pane is too narrow to read
Turn on the Wrap toggle in the toolbar so long lines fold into the pane instead of running off the side — remembering that it applies to every pane at once. If a file does not need to be visible right now, close its tab: the pane count follows the tab count, so the quickest way to make two panes wider is to have fewer tabs.
Dragging the tabs into a different order
Tab reordering waits until you leave compare mode — press ⎋ and the bar is draggable again, with each pane following its tab. Pinned tabs stay exactly where you put them, and unpinned tabs are held to the right of the pinned run, so your most-used files keep the same place in the bar all day.
What you can count on
- One pane per open tab, arranged the moment you press Multi View. The files you have open are the files you see, so the layout is always one decision away.
- Every pane is a full editor. Type in any of them; the caret follows the pane you click into, and each pane carries its own undo history.
- Each pane keeps its place. Scroll position, caret and selection stay put while you work in the pane next door, for as long as the session lasts.
- Each file is coloured for what it is. Our advanced language identifier gives a configuration file and a shell script their own colouring in adjacent panes, with nothing to choose pane by pane.
- Layout changes leave your files alone. Opening panes, collapsing them and comparing are all changes to the view; nothing is saved, closed or rewritten on your behalf.
- Two buttons to switch. Multi View and Single View sit together in the toolbar, and Move Pane Left and Right are on the pane's right-click menu.
- It all happens on your Mac. Nothing is uploaded, there is no account, and both files stay exactly where you keep them.
Frequently asked questions
How many files can I have side by side?
One pane per open tab, as many as you have open. Width is what decides the comfortable number: two or three panes give each file room to read on a typical display, and turning on Wrap keeps long lines inside narrower ones. Close the tabs you have finished with and the remaining panes widen to fill the space.
How do I get between two distant places in one file?
Set a bookmark where you are working with ⌘F2, then step between bookmarks with F2 and ⇧F2, or jump straight to a line number with Go to Line at ⌘L. Each one takes you straight to the place you meant, and the reference you want alongside can sit in the pane next door while you move around.
Do both panes scroll together?
In compare mode they can. Hold ⇧ and the two sides scroll in step, so matching sections stay level with each other while you read down. Release the key and each pane scrolls on its own again, which is what you want when you are reading one file and editing another.
How do I keep long lines readable in a narrow pane?
Turn on Wrap in the toolbar and long lines fold into the width of the pane instead of running off the side. It is one setting applied to every pane at once, including the ones not currently on screen, it is on by default, and it lives on the toolbar and in the View menu so it is one press away while you read.
How do I choose which two files to compare?
Open the documents you are interested in, then choose Compare Files… from the toolbar's Compare menu. The pairing canvas gives you a left slot and a right slot: click the card you want on each side and press Compare. With exactly two tabs open, Quick Compare pairs them for you straight away.
Does viewing files side by side change them in any way?
Both files come out byte for byte what they were. Panes are a layout, and the tints our comparison view paints are drawn over the text rather than written into it, so you can arrange, compare and collapse as often as you like and the documents on disk are untouched. Nothing leaves your Mac either: everything happens on your machine, nothing is uploaded, and there is no account.