How to See Image Dimensions and Video Length in a Folder List on a Mac
You need a photo at least 3,000 pixels wide for a print, or the shortest of twenty clips from a trip. In the Finder's list view, every file shows its size and kind, but not a picture's resolution (its width and height in pixels) or how long a video plays, so you end up opening files one by one.
The short answer: the Finder shows these details one file at a time, in File › Get Info (⌘I) or the preview pane, and in icon view Show item info writes a picture's dimensions under its name. To read them for a whole folder in a list, Folia Files has two optional columns, Dimensions and Duration, in its Detailed List and Tree views: right-click the column titles and choose them.
What the Finder shows, and where
No column for it in list view
In list view (View › as List, ⌘2), View › Show View Options (⌘J) lists the columns you can show: Date Modified, Date Created, Date Last Opened, Date Added, Size, Kind, Version, Comments and Tags, plus a few iCloud columns (iCloud Status, Shared By, Last Modified By). None of them gives a picture's dimensions or a video's duration. It is also the window where you turn on folder sizes, which list view leaves out at first.
Get Info and the Inspector
Select a picture or a video and choose File › Get Info (⌘I). The More Info section gives the Dimensions of a picture or a video and the Duration of a video or a sound. Hold ⌥ and the command becomes Show Inspector (⌥⌘I), a single window that follows the selection: handy to compare three files, not three hundred.
The preview pane and icon view
- View › Show Preview (⇧⌘P) adds a pane with details about the selected file, a photo's dimensions among them, and View › Show Preview Options chooses which details it lists. Still one file at a time.
- In icon view (View › as Icons, ⌘1), Show View Options has a Show item info checkbox. It adds a line under each name, and for a picture that line is its size in pixels. You see every picture at once, but not next to its date or file size.
Find files by pixel width or duration
A Finder search can pick them out. Press ⌘F in a Finder window. In the row of search criteria (click + if there is none), open the first pop-up menu, Kind, and choose Other…. In the list of attributes, pick Pixel width, Pixel height or Duration, then set, for example, Pixel width is greater than 3000. You get the photos wide enough, in that folder or on the whole Mac, although the results don't show their dimensions either.
Add Dimensions and Duration columns in Folia Files
Folia Files' panes have eight views, and two of them, Detailed List and Tree, list files in a table whose columns you choose. Dimensions and Duration are among those columns, hidden until you ask for them.
- Open the folder in a pane and choose View › Detailed List (⌘3), the view new panes start in, or View › Tree (⌘4).
- Right-click (or Control-click) the row of column titles. The menu lists every column except Name: Date Modified, Size, Kind, Date Created, Date Added, Dimensions and Duration. A checkmark shows the ones on screen.
- Choose Dimensions, then open the menu again and choose Duration. Choose a column again to hide it.
- Drag a column's title to move it, and the edge of its title to change its width.
Folia Files keeps your choice, one set of columns for Detailed List and another for Tree.
What the two columns show
- Pictures (JPEG, HEIC, PNG…): width × height in pixels, as the picture is displayed. A photo taken upright reads 3024 × 4032 rather than 4032 × 3024, because its orientation is taken into account.
- Videos: their dimensions, as they play (a clip filmed upright on a phone is taller than wide), and their duration.
- Sounds: their duration.
- Durations read in minutes and seconds (3:07), with the hours from one hour on (1:02:45). Other files leave both cells empty.
How Folia Files reads them
Folia Files reads what each file says about itself (the header of a picture, the track information of a video or a sound) without decoding the image or playing the clip. It works in the background and only on the rows on screen, the last ones you scrolled to first, so opening a folder of thousands of photos doesn't mean reading thousands of files: the values come in as you scroll. What a file doesn't say, Folia Files asks Spotlight.
Where they stay empty
- Servers and network shares (SMB, SFTP, WebDAV…), and cloud drives mounted as a disk: Folia Files reads nothing there for these columns, as a server that stops answering would stall them.
- Files kept online only by iCloud Drive or a cloud app: reading one would download it, so Folia Files never opens them and asks Spotlight instead. Their cells show what Spotlight knows, and may stay empty.
No sorting by these columns
A click on the title of Dimensions or Duration doesn't sort the list, and neither is in View › Sort By. That's deliberate: Folia Files saves each pane's sort order and keeps what it saves readable by its earlier versions, which don't know these columns. To read down the videos without the photos, choose View › Group By › Kind in Detailed List: each kind of file gets its own group (more in how to group files by kind, date or size).
One file in detail: the Info module
When one file matters, select it and choose File › Info (⌘I): the Info module opens in the right sidebar and follows the selection from then on. A picture gets an Image section: its dimensions with the megapixel count, its colors and, when the photo records them, the camera, lens, exposure, date taken and location, with Show in Maps. A video gets a Video section: its duration, its dimensions (marked 4K, 1080p or 720p), frames per second, video codec and bitrate, then its audio track. Info is one of the modules you can place in the right sidebar, under the left sidebar's list or in a pane of its own.
Act on pictures by size
Seeing the dimensions often comes before resizing. The Batch Actions (Photos and Videos) tool, under the toolbar's Tools button, picks its files with criteria: click Selection Options, add a criterion with the + button and choose Image Width (or Image Height), is greater than, 4000. The list then keeps only the photos wider than that, ready to be resized together.
