macOS High Sierra full review

When you install High Sierra on your Mac you might not notice a big difference, but appearances can be deceptive.

While High Sierra hasn’t had a massive interface overhaul like the one Yosemite brought in 2014, and despite the fact that many of the features gained by its bundled apps feel a little like it is playing catchup with iOS, this version of macOS actually has a lot going on behind the scenes.

And it’s what’s going on in the background that makes this version of macOS well worth the upgrade.

That and the fact that, like all versions of the Mac operating system since Mavericks in 2013, it’s free!

Sierra to High Sierra

We were expecting High Sierra to be an update similar to Mac OS X Mountain Lion and Snow Leopard. These were smaller updates that came after the more flashy Lion and Leopard versions of OS X. Each bought a handful of new features but mostly focused on under-the-hood changes, rather than improving the apps we use day-to-day.

Where Show Leopard rewrote the Finder in Cocoa, brought Grand Central Dispatch, and improved power management, Mountain Lion bought Gatekeeper and focused on making it easier to manage and synchronise content between multiple Apple devices.

This time round Apple has completely overhauled the way that the macOS manages and organises your data, as well as adding support for new photo and video codecs that will mean that your increasingly large media files take up less space.

The sad thing is you probably won’t notice this unless you work with large files. But the changes add up to a faster, more secure and more stable operating system. You will just have to take our word for it. (Or you can read the information about AFPS, HEVC and HEIF below.)

Luckily, for those who are bored by such geeky things, there are a few improvements to apps that you will notice, especially the improvements to Photos and the changes in Safari (although these Safari changes are also available to those running Sierra and El Capitan, so not unique to Safari in High Sierra). More on those changes later.

MacOS High Sierra Compatibility

First things first, can you even run macOS High Sierra on your Mac?

The good news is that if your Mac is running Sierra then it can run the macOS High Sierra. Those machines are:

  • MacBook (Late 2009 or later)
  • MacBook Air (2010 or later)
  • MacBook Pro (2010 or later)
  • Mac mini (2010 or later)
  • Mac Pro (2010 or later)
  • iMac (Late 2009 or later)

However, some features, like HEVC encoding and decoding, and anything VR related, will require more recent models and processors.

APFS How macOS High Sierra has overhauled the file system

We are going to endeavour to explain the changes to the file system of macOS in layman’s terms. We will try and give a few real-world examples that might make a difference to an average user. This underplays a lot of what’s on offer here, but it should give you the general idea.

In High Sierra Apple has replaced the primary file system of MacOS. Apple File System (APFS) is the successor to the old Hierarchical File System (HFS+), which has been around since the beginning of 1998, so it’s pretty ancient.

We aren’t talking about anything you would see in the Finder here. This is the way that your Mac manages and organises all your data.

Apple has made changes to HFS+ over the years, but it really needed to go back to the drawing board and start again, and with APFS it has. As a result the Mac file system is set up for the future.

It’s not just the Mac that uses APFS either. iOS 10 rolled APFS out to iPhones and iPads back in 2016, and when users updated their phones to the new OS they were pleased to see that they had recovered a few GB of space.

We were curious to see whether we’d see increased space following the installation of High Sierra on our Macs, so we took a trip to the Apple menu > About This Mac, and checked the Storage stats before and after the installation.

We did recover some space. When you first look at the storage graph that your Mac generates you may be disappointed, but patience is a virtue and after your Mac has finished its shift to APFS you can expect to be rewarded with some lovely free space.

That’s not the only way that Apple’s switch to APFS will benefit you. When it comes to copying large files the process will be faster. We ran our usual file transfer speed test before and after the update to High Sierra. This involved copying a 4GB file. Before we updated the 4GB file copy took 8.41 seconds. Afterwards it was instantaneous. You will never see a Duplicating file window again.

There is a caveat with this ‘copying’ though. The file isn’t being duplicated at all. It is essentially a writable clone of the original file. Rather than duplicating the original, the cloned file stores the changes that are made to it in the metadata and points to the original for the rest of the data. You could say it’s bit like making an alias, except that any changes made to the cloned file will be attached to that version of the clone, rather than reflected in the original. It’s also a little like the way Time Machine works - rather than copying every thing on your Mac each time, it just keeps track of the changes.

The other thing you need to keep in mind here is that if you have filled your Mac up with 100 copies of a what was originally a 4GB file, deleting all of them will not recover 400GB of space.

Speaking of space, there is another way you might notice a change, courtesy of APFS. If you have multiple partitions on your Mac (perhaps you run lots of virtual machines, or maybe you are just running Sierra and High Sierra consecutively), a new feature of APFS means that the size of the partition will not be limited.

In other words, previously, if you had given 250GB to your Sierra partition and 250GB to Yosemite, but your Sierra partition had needed more space, you could not grab some GB from Yosemite. Now both of your partitions have access to the same 500GB volume - existing in the same physical space. Both partitions could effectively have 500GB of storage space available - and crucially if you needed more you could add external storage to the volume at a later date.

Another way that APFS could make a difference to you without you being aware is it’s built-in crash protection. Even your system ran out of power mid-transfer everything will stay in sync. When your computer starts up again the file you were attempting to transfer won’t have been corrupted.

There are lots of other features coming with APFS that will impact you without you really being aware of them, from built-in encryption, which no longer requires File Vault to work, and Snapshots, which can capture the state of your files at any moment in time. The latter should improve Time Machine as snapshots will take up less storage and copy quicker.

What all this boils down to is a Mac that should offer faster, more efficient, and more stable performance. That’s as long as you have an SSD (aka Flash storage), which will be automatically converted to APFS by High Siera. At the time of launch APFS, was only available to those with solid-state drives in their Mac. Apple has promised that it will bring APFS to Macs with hard drives and Fusion drives in a future update.

Luckily macOS still supports HFS+, so if you have external drives you won’t need to convert them. If you add a new external drives you can choose to update it to APFS though. Of course, if you do so it won’t be readable by devices that aren’t running High Sierra.


The other way that Apple is paving the way for the future with MacOS High Sierra is its adoption of two new codecs: HEVC and HEIF.

HEVC stands for high-efficiency video codec, and it’s another name for H.265, the successor to H.264. The new codec is necessary because video sizes are now so much larger thanks to 4K and HDR. HEVC compresses these extremely high resolution files so they don't take up take up as much space (which is good news if you are shooting lots of video in 4K on your iPhone 8 Plus).

There is also a new file format for images. The high efficiency image file format (HEIF), like HEVC, makes file sizes even smaller than the ageing Jpeg file format would. Read about HEIF here.

Wondering why a new file format for photos is necessary? Our image files are also taking up more and more space. Take a Live Photo taken on the iPhone 8, or a Portrait Mode photo taken on the iPhone 8 Plus, that image file will include depth data in the case of Portrait Mode, and motion elements in the case of a Live Photo. All that information can now be stored as part of the image file itself - which means you can be creative with that data later on.

The only issue here, at launch in any case, is compatibility. Some apps may not know how to deal with HEIF files yet (for example, initially Photoshop didn't, but it does now). However, even for those apps that don't support the format, you can export H.264 and JPG versions of your videos and photos so that shouldn’t be a big issue - and eventually everyone will catch up, this is an industry standard after all, rather than Apple inventing it’s own.

While there isn’t a lot of content available yet in HEVC, and HEIF is yet to become mainstream, you can expect these standards to become a lot more common in the future. And Apple will be ready for that.

You will only be able to take advantage of the new formats if you have an iPhone that can create HEVC and HEIF files, that’s an iPhone 7 or later, or the latest generation of iPad Pro.

Metal 2 and VR

We still have a few more geeky bits to get through here, but they will have practical applications for you if you enjoy gaming. And even if you aren’t a gamer they will still make a difference to your experience of your Mac’s interface.

A couple of years ago Apple introduced Metal, a framework that bypassed OpenGL and allowed developers to tap in to the computational power of the graphics processor. Metal 2 is the successor to Metal and it will increase GPU performance and gain support for VR.

This is great news for anyone who wants to immerse themselves in VR gaming - but note that your Mac may not be able to take advantage of this as it depends on your processor and your GPU (but it will add support for external GPUs in the future).

Unfortunately there isn’t a lot of Mac-compatible VR software available, or software written to take advantage of Metal 2 for that matter. However, Apple did announce that Mac users would be able to plug in the HTC Vine running SteamVR (not the Oculus Rift, yet).

The company is also working with Valve, Unity and Epic, so you can expect to hear even more about VR gaming on the Mac soon.

For anyone who doesn’t really care about VR, you’ll be glad to hear that Metal 2 will also mean that your Mac's user interface and any animated effects will look smoother.

Changes to the apps in High Sierra

Now on to the everyday apps that are bundled in macOS. As has been the case over the past few years, the changes in the macOS apps have tended to reflect functionality that has just become available to the iOS versions of those apps (or in some cases has been available for a generation or so).

This time round it feels a little like some of the macOS apps - well one macOS app in particular - has gained back some of the functionality it had before it was ‘dubbed down’ to the level of the iOS equivalent.

We’ll start off by discussing the changes in that app, Photos.


Photos is the one app in High Sierra that gets the most changes, but for anyone who used to use iPhoto or Aperture, it feels a little like Photo has regained some of the features we used to rely on, and become a more professional app.

There are some new features that you will recognise from iOS 11, including new ways of editing Live Photos so that you can turn them into gifs and long exposure shots, and the same new filters that you’ll see in Photos on the iPhone or iPad. There’s also improved facial recognition. We’ll take a quick look at each of these below, but you can read more about the changes in Photos here.

The other big change is that it’s a little easier to find your way around the app because the menus are better organised and the Edit mode has been redesigned making it easier to find the tools you want.

We’ll start with the new editing features for Live Photos. You have a few choices here, all of which will make Live Photos something that we will be less inclined to turn off on our phones. It has to be said that Live Photos has been a bit of an annoyance until now, it was often the case that the photo would capture some movement either side of the action, so, for example, the clip would finish with someone putting the phone down. Then you had the annoying audio of someone shouting that would inevitably end up in the background. It often didn’t add up to anything to be proud of.

The changes in Live photos address this as you can finally trim the clips and turn off audio. You can also choose a different still image to represent the clip. But best of all you can turn your clip into something that resembles a gif. In fact there are two types of animation on offer, a Loop and a Bounce, and a Long Exposure effect that you could to capture firework trails or moving water. It’s simple and effective.

Photos also plays better with third party apps, so it’s really easy to open a photo directly in Photoshop, use the editing tools from that app, and save your edits to the Photos library. However, there are some new editing tools available in Photos that might make you less likely to open up Photoshop in the first place.

The new editing tools in Photos include Curves, for adjusting colour and contrast, and Selective Color, so you can swap one hue for another.

There are also new “professionally inspired filters” replacing the nine that were in Sierra. We had high hopes for these, recalling the filters provided in Aperture that mimicked actual photographic styles, but these are basically variations of three different styles: Vivid, Dramatic, and black and white, with warm and cool options. We’re a little disappointed to be honest.

One final thing to mention about Photos is the improved Facial recognition. Apple has claimed to be able to sort your Photo library using facial recognition for generations but it’s never really been that good at it. This does appear to have changed in Photos in High Sierra. The difference is that you need to put a little more effort in helping Photos sort out who is who, but it will use machine learning to identify other photos with the same person in them. For example, if you confirm that your son features in one photo from last Tuesday, Photos will look out for him in other photos from last Tuesday.

It will do a lot of the work in the background, so every now and then you will be asked to confirm if someone is who Photos thinks it is, and in so doing it will enhance its knowledge.

You might be wondering why you’d even want to spend the time helping Photos sort out who's who. One reasons is the Memories feature, which automatically pulls in photos and videos and creates a montage for you. These can be a bit haphazard we find, but the more Photos knows about your photos the better these montages are. Tell it which photos include your kids and you can expect to see some nice movies.

Memories is able to recognise a few more categories including babies, pets, weddings, birthdays and sports events. If you want to fine tune your Memories it's still a lot more complicated than Apple processes would usually be, we have a tutorial about creating your own Photos and Video slideshows using the Memories feature here.


The other app that got some attention when Macs were updated to High Sierra was Safari - however, the Safari 11 update wasn't restricted to Macs running High Sierra.You can install Safari 11 on all Macs running El Capitan, Sierra, or High Sierra. Still, it's a great update and definately worth updating your Mac to run it if you aren't yet on any of those operating systems.

Apple’s aim with Safari 11 is to make Safari the fastest web browser and our tests prove that it achieves that.

One way in which Apple is able to speed things up is that it is addressing some of the aspects of the web that slow things down. Sierra 11 will automatically stop auto-playing videos that have sound from running - which is great if you tend to jump out of your skin every time you visit a website that has an autoplaying video blaring out.

It will also stop cookies from tracking you - which should mean that you don’t see ads everywhere relating to the holiday you were thinking of booking. But in practical terms should speed up what goes on in the background when you visit a page and all the trackers associated with each ad start clambering for your information.

So it’s good on both counts - you don’t have to listen to auto-playing videos (they will still play if the sound is set to be off), and you don’t have to feel that advertisers are stalking you. But most of all the performance will improve. And if a web page is still not performing well then you can choose to use the Reader view.

Reader view was introduced a few generations ago but now you can set it on a per-site basis, so if a particular site you use is loaded with ads, you could choose to always see it in Reader view. Remember though that those ads are probably how the people who make the website you are visiting get paid. You can also choose to set your browser to never auto-play video, regardless of whether it has sound.

All this boils down to an even more power-efficient Safari which Apple promises can deliver an extra two hours of web browsing and four hours of Netflix streaming.

Safari 11 isn’t a reason to update to High Sierra in itself though. Safari 11 is also available to those running Sierra and El Capitan - to get it you need to update your Mac to the latest version of those operating systems. Plus, as good as Safari may be, some of the and services you use may not run well in Safari and if that’s the case you won’t be able to enjoy its new features.


Mail gets a couple of tweaks in High Sierra. The main change is the addition of Top Hits, which will give you a couple of suggestions of the most likely email you are searching for based on factors such as how often you engage with the sender. You will find what Mail believes are the two most relevant emails at the top, followed by the rest of your messages in chronological order.

When we first started using this feature we kept missing the first two emails - if you know you are looking for an email from last month you don’t expect to see it at the top - but we expect we will get used to it.

Apple has also improved full screen viewing in Mail. If you work in Full Screen view, when you open an email and then choose to reply the original will take up one half of the screen and the reply, the other half. Previously the reply would have covered the original so this way makes it easier to see what you are replying to. Of course if you don’t use Full Screen mode you can easily view two emails at once.


We’ve not really sold on the idea of using Siri on our Mac. We’re sure that it’s a useful feature to be able to ask Siri to turn on Bluetooth, or to play a particular album in iTunes. But frankly we don’t use it because the majority of the time, when we think of something to ask Siri we are in a crowded office and don’t want to look silly.

The good news is that in High Sierra, hidden away in the accessibility options, is the opportunity to do just that. System Preferences > Accessibility > Siri and choose Enable Type to Siri. Now if you trigger Siri a keyboard will appear into which you can type your query. Now we just need a way to trigger Siri that doesn’t involve clicking on the Siri icon, a Siri button on the keyboard perhaps? (We have some Siri tips here for using Siri on the Mac).

Funny enough that’s not the new feature that Apple’s pushing for the new version of Siri. Apple is more proud of Siri’s natural-sounding voice in High Sierra and iOS 11. The result is a Siri that is slightly less robotic and more colloquial. There’s also better music integration so you can treat Siri like a bit of a DJ and ask it to create playlists for you, and it will learn what you like and make recommendations.

Siri and Spotlight now offer flight information and multiple Wikipedia results.

The rest of the app updates are a little smaller, but still significant, we’ll describe them below.


We use Notes on our iPhone for everything so we were really excited that in macOS High Sierra Notes gained some enhancements.

One change in Notes has us particularly excited is the fact that we can Pin Notes we need to access frequently to the top. We’ve lost count how many times we’ve scrolled through looking for information we have stored in Notes. This is the answer to our prayers!

You will also be able to create tabled in Notes both on the iPhone, iPad and Mac. Great news, but probably not as ground breaking as the ability to make check lists that came in iOS 9 and El Capitan.

In iOS 11 Notes gains the ability to scan documents, of course there is no such feature here. What we’d really like to see is a plain text mode - currently if you copy and paste you are stuck with the text style used by the source. It would be nice to have a bit more flexibility over styles and formatting.

FaceTime, Messages & iCloud

In FaceTime you will be able to capture a Live Photo from a FaceTime call (you can also do this in iOS 11).

What would really be useful is FaceTime conference calling, despite the fact that this was possible in iChat many years ago.

Another small change that’s likely to make a huge difference, your Messages will stay in sync across all your devices. So if you have opened your Messages on your phone you won’t see them all listed as unread on your laptop when you open it up. If you hate seeing red dots alerting you to unread messages only to find that you had read them, this will probably make your day.

In High Sierra it will be even easier to share large files with people via iCloud. If you want to share a file that already resides in your iCloud, just select the file, click the Share button, and select Add People. Then select the way you wish to send a link that the recipient can use to access the file, choose from Mail, Messages, AirDrop etc, even Copy Link, and add your contact. When the contact receives the invitation they will be able to access the file on any device (they will need to install iCloud for Windows if they are on a PC). The recipient can then edit the file.

Touch Bar

If you have a MacBook Pro with Touch Bar there are a few tweaks just for you. It’s a little less fiddly to control brightness and volume, and there is a new option for enabling Night Shift and AirPlay (added via System Preferences). You’ll also find a new colour-picker, a Now Playing button and a shortcut to picture-in-picture.

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