How do you take a screenshot on an iPhone or iPad? By pressing the sleep/wake/power button (at the top-right of the device) and the Home button (below the screen) at the same time. The screenshot will then appear in your Photos app. It's as easy as that!
But in case you're interested in a few little exceptions and extra tips - such as ways to take a screenshot if one of the hardware buttons on your iPhone or iPad is broken, or how to convert the screenshot into a jpeg - then read on, because we answer this query in a little more depth below.
Updated 6 October to include the iPhone 7 and 7 Plus.
Screenshot tips: Why would you take a screenshot on an iPhone or iPad?
The word screenshot is a contraction of screen and snapshot. Also known as a screen grab or a screen capture, a screenshot is a picture - a static image - of what's on your screen at any given moment.
Why would you take a screenshot on an iPhone or iPad? For a journalist the answer is obvious: here on macworld.co.uk we use screenshots to illustrate iOS apps and games so you can see what they look like, to show off features in iOS itself, and to illustrate individual steps in tech tutorials.
But screenshots can be useful for all iPhone and iPad owners. You might use screenshots to show off to your friends: "Take a look at this incredible moment I engineered in the game XCOM," for instance. More practically, you might use a screenshot to show a tech-savvier friend a weird error message that was coming up, or a strange behaviour your iPhone was exhibiting, so they can offer advice. (Or the reverse situation: if your mum can't work out what's happening or her iPhone and you'd rather not drive round there, you could ask here to send over a screenshot of the problem.)
How to take a screenshot on an iPad or iPhone
To create a screenshot of whatever's on your iPhone or iPad display, press the sleep/wake/power button (at the top-right of the device) and the Home button (below the screen) at the same time. It can be a bit fiddly doing this while doing something cool and screenshot-worthy in a game, as all iOS games reviewers discover.
This principle also applies to the non-mechanical button found on the iPhone 7 and iPhone 7 Plus too.
The screen will flash once, to show it's captured an image (you'll also hear the camera's shutter sound effect), and the screenshot will be saved to your Photos app - the collection that used to be known as your Camera Roll.
To see the screenshot, go back to the Home page and tap the Photos icon, and you'll see the screenshot at the bottom of the Photos tab (the leftmost option along the bottom of the screen). If you want to send this to someone straight away you can tap Share (at the top-right of the screen), tap the screenshot to select it, and then tap the sharing icon (the arrow pointing vertically up from a square) at the top left. Select Message, Mail, Twitter or however you want to send the image. Alternatively, you can simply tap the image itself to blow it up to full screen, check it's what you wanted, and then tap the sharing icon from there. It'll be at the bottom-left.
Screenshot tips: How to convert iPhone and iPad screenshots from .png to .jpg
Bear in mind that iOS saves screenshots in the .png format; this can be a little confusing, since it saves images taken by the Camera app as .jpgs. (There are valid reasons for this distinction, but we shan't concern outselves with them here.) If you want to send the screenshot to someone as a .jpg, or upload it to a service that doesn't accept .png files, you'll need to convert it.
Some clever iPad and iPhone users have tried to come up with ways to convert the image on the iOS device itself - one technique involving DropBox is discussed on this forum thread.
But we find that the simplest solution is to save the image to your Mac (plug the iOS device into the Mac, open Image Capture, select the iPad or iPhone in the lefthand menu, scroll down to the bottom of the list of images and drag-and-drop the screenshot on to your Mac's desktop - or if you're running OS X Yosemite and have a sufficiently advanced iOS device, simply AirDrop it across) and then open it in Photoshop or another image-editing program. Now you can select Save As (or Shift, cmd, S) and save it as a .jpg file.
Screenshot tips: How to take a screenshot on an iPhone or iPad if the buttons don't work
If the sleep button or Home button on your iPhone or iPad doesn't work properly (and this has historically been a common complaint among iPhone users in particular - although the situation seems to be improving), it's still possible to take screenshots.
Take a look at our workaround for broken iPhone power buttons. This simple tip explains how to create a 'software button' on your iPhone or iPad screen that you can use if the hardware buttons have malfunctioned. Sure enough, this software button can be used to take screenshots too.
Tap the little circle (which is activated via the Settings apps - go to Settings, General, Accessibility and scroll down to AssistiveTouch and turn it on) to bring up the palette of options, then tap Device, then More, and you'll see a Screenshot option. Tap it and iOS will grab a screenshot.
(After minimising itself and becoming temporarily invisible - indeed, this widget appears to be un-screenshottable. We usually take a photo of the device's screen with another camera, as we've done below, but if anyone has worked out a clever way around this, do let us know.)