# How to Take a Screenshot on iMac

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Source: https://www.lazyscreenshots.com/blog/screenshot-imac/
Source observed: 2026-09-15T21:51:20.682Z
Last checked: 2026-09-15T21:51:20.682+00:00
Indexed: 2026-09-15T21:57:19.086+00:00

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# How to Take a Screenshot on iMac

**May 20, 2026 · LazyScreenshots Team**

We created this guide for iMac users who need to capture screens, selected areas, windows, menus, displays in multi-monitor setups, or recordings. The standard Mac shortcuts also work on iMac, while large Retina displays, multiple monitors, and third-party keyboards introduce additional considerations.

## The three keyboard shortcuts every iMac user needs

| Shortcut | What it captures |
|---|---|
| `Cmd+Shift+3` | Full screen; saves one file per connected display |
| `Cmd+Shift+4` | Selected area; drag a crosshair to define the region |
| `Cmd+Shift+4` then `Space` | Specific window or menu; click the highlighted window |

Each shortcut saves a PNG file to the Desktop by default. A floating thumbnail appears in the bottom-right corner for five seconds. Click it to annotate with Markup, or let it disappear to save the file as-is.

### Copy to the clipboard instead of saving a file

Add `Ctrl` to the shortcuts to copy the capture to the clipboard:

- `Ctrl+Cmd+Shift+3` — full screen to clipboard
- `Ctrl+Cmd+Shift+4` — selected area to clipboard
- `Ctrl+Cmd+Shift+4` then `Space` — window to clipboard

This lets you paste directly into Slack, email, or a document without creating a Desktop file.

## Using the Screenshot toolbar (`Cmd+Shift+5`)

Press `Cmd+Shift+5` to open the Screenshot toolbar at the bottom of the screen. It provides:

- **Capture Entire Screen**
- **Capture Selected Window**
- **Capture Selected Portion**
- **Record Entire Screen**
- **Record Selected Portion**

Select **Options** to change the save location, set a 5-second or 10-second timer, show or hide the floating thumbnail, and include or omit the mouse pointer.

## iMac display resolutions and screenshot file sizes

Large, high-resolution iMac displays can produce larger files than MacBook Air or MacBook Pro screens.

| iMac model | Display resolution | Full-screen screenshot size |
|---|---:|---:|
| 24-inch iMac (M1, M3, M4) | 4480 × 2520 | 5–12 MB (PNG) |
| 27-inch iMac (2019–2020) | 5120 × 2880 | 8–18 MB (PNG) |
| iMac Pro (2017) | 5120 × 2880 | 8–18 MB (PNG) |
| 21.5-inch iMac (non-Retina) | 1920 × 1080 | 1–3 MB (PNG) |

Screenshots are captured at native Retina resolution rather than the scaled resolution shown in **System Settings > Displays**. For example, a 24-inch iMac set to “Looks like 2560 × 1440” still produces a 4480 × 2520-pixel screenshot.

To change the default format from PNG to JPG, run:

```bash
defaults write com.apple.screencapture type jpg
```

A 24-inch iMac JPG is typically 500 KB to 2 MB instead of 5–12 MB for PNG, with slight compression artifacts in text and UI edges.

We also offer LazyScreenshots for automatically compressing and beautifying iMac screenshots with backgrounds, annotations, and device frames. [Try LazyScreenshots Free](https://www.lazyscreenshots.com/)

## Screenshots with multiple monitors on iMac

An iMac can be used with an external monitor, Studio Display, or iPad through Sidecar.

### Capture all displays

`Cmd+Shift+3` saves a separate PNG file for each connected display. With the iMac screen and one external monitor, you receive two Desktop files. Timestamped names use a number suffix to distinguish them.

### Capture only one screen

1. Press `Cmd+Shift+5` to open the Screenshot toolbar.
2. The toolbar appears on the primary display; drag it to the display you want to capture if needed.
3. Click **Capture Entire Screen**, then click the specific screen.

For a region on one display, press `Cmd+Shift+4` and drag across the desired area.

### Sidecar: iPad as a second display

With an iPad connected through Sidecar, `Cmd+Shift+3` captures the iMac and iPad as separate files. To capture only the iPad, press `Cmd+Shift+5` and click the iPad display.

## Third-party or Windows keyboards on iMac

For a Windows, mechanical, or other third-party keyboard, use these key mappings:

| Mac key | Windows keyboard equivalent |
|---|---|
| `Cmd` | `Windows` key |
| `Option` | `Alt` |
| `Ctrl` | `Ctrl` |

The corresponding shortcuts are:

- `Win+Shift+3` — full screen
- `Win+Shift+4` — selected area
- `Win+Shift+5` — Screenshot toolbar

### Remap the Print Screen key

1. Open **System Settings > Keyboard > Keyboard Shortcuts > Screenshots**.
2. Click the shortcut to change, such as **Save picture of screen as a file**.
3. Press `Print Screen` to assign it.

Afterward, pressing `Print Screen` takes a full-screen screenshot.

## Where iMac screenshots go

By default, screenshots are saved as PNG files on the Desktop. A filename may look like `Screenshot 2026-05-20 at 10.30.15 AM.png`.

### Change the location with the Screenshot toolbar

1. Press `Cmd+Shift+5`.
2. Click **Options**.
3. Under **Save to**, choose **Desktop**, **Documents**, **Clipboard**, **Mail**, **Messages**, **Preview**, or **Other Location**.

### Set a custom location with Terminal

For example, to use a Screenshots folder inside Pictures:

```bash
defaults write com.apple.screencapture location ~/Pictures/Screenshots
killall SystemUIServer
```

Future screenshots use that folder. The folder must already exist; macOS does not create it.

## iMac screenshot tips and tricks

- **Remove the window shadow:** Hold `Option` while clicking a window in `Cmd+Shift+4` then `Space` mode.
- **Lock the selection to a dimension:** While dragging with `Cmd+Shift+4`, hold `Shift` to constrain movement horizontally or vertically.
- **Move the selection while drawing:** Hold `Space` while dragging to reposition the selection without resizing it.
- **Cancel a screenshot:** Press `Esc` at any point.
- **Disable the floating thumbnail:** Open `Cmd+Shift+5`, select **Options**, and uncheck **Show Floating Thumbnail**.
- **Capture a menu bar or dropdown:** Open the menu, press `Cmd+Shift+4`, and drag over the menu. The menu remains open during area selection.

## Taking screenshots on iMac with Terminal

The `screencapture` command provides programmatic control for automation, scripts, and captures from SSH:

```bash
# Full screen to file
screencapture ~/Desktop/screenshot.png

# Interactive selection (same as Cmd+Shift+4)
screencapture -i ~/Desktop/screenshot.png

# Specific window (same as Cmd+Shift+4+Space)
screencapture -iW ~/Desktop/screenshot.png

# Capture to clipboard
screencapture -c

# Timed capture (5-second delay)
screencapture -T 5 ~/Desktop/screenshot.png

# Capture without the window shadow
screencapture -iWo ~/Desktop/screenshot.png
```

## Screenshot not working on iMac? Quick fixes

1. **Check keyboard shortcuts:** Go to **System Settings > Keyboard > Keyboard Shortcuts > Screenshots** and ensure the shortcuts are checked.
2. **Check for app conflicts:** Some screenshot tools and keyboard remappers override the default shortcuts. Quit third-party apps one at a time to identify the conflict.
3. **Restart SystemUIServer:** Open Terminal and run `killall SystemUIServer`.
4. **Check disk space:** Screenshots may not save when storage is full. Check **System Settings > General > Storage**.
5. **Test the keyboard:** With a third-party keyboard, enable **Show keyboard viewer in menu bar** under **System Settings > Keyboard** to confirm that key presses register.

## Related guides

- [Mac Screenshot Keyboard Shortcuts](https://www.lazyscreenshots.com/blog/mac-screenshot-keyboard-shortcuts/)
- [How to Screenshot Multiple Monitors on Mac](https://www.lazyscreenshots.com/blog/screenshot-multiple-monitors-mac/)
- [Screenshot on Mac with External or Windows Keyboard](https://www.lazyscreenshots.com/blog/screenshot-external-keyboard-windows-mac/)
- [Where Do Screenshots Go on Mac?](https://www.lazyscreenshots.com/blog/where-do-screenshots-go-mac/)

---

## Related searches on www.lazyscreenshots.com

Each link returns Markdown search results.

- [How to Take a Screenshot on iMac](https://lazyscreenshots.mudpie.ai/s/how-to-take-a-screenshot-on-imac.md?trace=t_6dc436eaaf66)
- [Why iMac screenshots are different from MacBook screenshots](https://lazyscreenshots.mudpie.ai/s/why-imac-screenshots-are-different-from-macbook-screenshots.md?trace=t_6dc436eaaf66)
- [The three keyboard shortcuts every iMac user needs](https://lazyscreenshots.mudpie.ai/s/the-three-keyboard-shortcuts-every-imac-user-needs.md?trace=t_6dc436eaaf66)
- [Copy to clipboard instead of saving a file](https://lazyscreenshots.mudpie.ai/s/copy-to-clipboard-instead-of-saving-a-file.md?trace=t_6dc436eaaf66)
- [Using the Screenshot toolbar (Cmd+Shift+5)](https://lazyscreenshots.mudpie.ai/s/using-the-screenshot-toolbar-cmd-shift-5.md?trace=t_6dc436eaaf66)

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