Is Apple iOS Big? (Different Version Sizes Checked Out)

The iOS is the operating system in iPhones and iPods. Each version differs from the other, and the first thing to do before downloading is to check whether you have enough space. This article is your ultimate guide on the size of each update and how much space you need.

While previous iOS versions are less demanding, requiring 1-2GB of free space to download, the latest heavy systems like iOS 14 and 15 need up to 3 GB or more even with advancements in technology from Apple, including better compression. All operating systems have various sizes that differ depending on the type of device and the system configuration.

Additionally, considering other factors, your phone may also want more space to handle the installation of the new iOS. The only remedy is to free up as much room as possible from idle applications and cache. 

If you want to update your device to enjoy all the features of the latest updates, you want to know how much space will be enough.

Installing a new iOS on your iPhone is almost the same as downloading a new application from the AppStore. Your device should have sufficient space to accommodate the system; otherwise, it will fail to install. The only challenge users face is not knowing how much space an update requires for them to free up enough room for it.

You require 1.5- 2GB of space to download any iOS. Apart from leaving space for the system, you also need room for installation of about the same amount as the update. In most cases, updating your device to the latest software is challenging if you have less than 16GB of storage.

Also, note that new updates are heavier, unlike updating to a version of the same iOS, which usually uses hundreds of MBs. For instance, updating from iOS 14 to iOS 15 is heavier than upgrading from iOS 15 to 15.5.

One of the best aspects of Apple is how attentive it is to clients’ needs. The developers are constantly working tirelessly to improve the user experience, and you can tell from the number of updates they release.

From the first iOS version to the most recent iOS 16, there has been a significant improvement in the iPhone’s performance to cater to the ever-changing market needs. It explains why users are often on the lookout for updates to install.

While significant updates need up to 2GB of space, minor in-system fixes will only use hundreds of MBs. If the download fails due to lack of space, the next step is to delete some files you don’t need and clear the data you previously erased.

Another overlooked requirement is that your phone should have enough power, preferably more than 50%, because the update can deplete the battery and turn off the phone which is risky to the system.

Experts state that it is tasking to download a new iOS if you only have less than 8GB of free storage. The only remedy in such cases is to delete unnecessary files. An exception is the iOS 9 version, where Apple incorporated a new tech where the system can download files you previously deleted after a successful update.

The iOS 10.3 came with enhancements from Apple, where storage goes to a solid state, allowing the device to accommodate more data.

To better understand the sizes of various Apple operating systems, it may help to discuss each of the most recent updates to know how much space you need. Including the unsupported versions like iOS 8 and narrowing down to the most recent release, the iOS 16, here is the list of each operating system.

iOS 8

To successfully install iOS 8, you may need up to 6GB of space in your iPhone. The operating system may even extend in size depending on your type of iDevice. Some gadgets compatible with the software include the iPad Air, iPad Air 2, and third and fourth version iPads. The iPhone 6, iPhone 6 Plus, iPhone 5, and iPhone 4S also support the iOS 8.

Conversely, the original iPad and iPhone 4 Plus, alongside the older models, are incompatible with the system. Apple’s iOS 8 official release date was 17 September 2014 to succeed iOS 7. The software requires such a massive download capacity, although its actual size is about 2GB because it needs space to compress old files whenever you update.

iOS 9

The manufacturer released the 9th system version on 16 September 2015, exactly one year after the previous iOS launch. Unlike its predecessor, Apple managed to significantly reduce the software size to about 1GB, although there may be slight variations depending on your iDevice.

The shrink happened due to advancements in App technology. Additionally, many Apple users complained to the manufacturer about the excessive space required given the storage size in most iPhone versions.

iOS 10

Depending on your iPad, iPhone, or iPod model, the iOS 10 size may vary from 1GB to about 2.5GB. Similar to iOS 9, it doesn’t take up vast storage space. Apple released the software on 13 September 2016 to support the iPhone 6s Plus, 6s, 6, 6 Plus, and all the iPhone 5s.

The iPad Pro and iPod 6 also enjoy support. The iOS 10 came with exciting features and updates to enhance the user experience. For instance, iOS 10.3.1 up to 10.3.3 focused on fixing bugs and advancing the safety and privacy of the user.

iOS 11

The eleventh system software version occupies only approximately 2GB of your iDevice’s storage space. Still, thanks to App Thinning technology, the latest iOS doesn’t take up extra space. Apple officially announced it on 19 September 2017, about one year after the previous release.

The iDevices that can conveniently run iOS 11 include all the iPhone six versions, iPhone 7 Series, iPhone SE, iPhone 5s, iPhone 8 Series, iPad Air, and later makes. Unfortunately, the 4th iPad generation, iPhone 5, 5c, and 4s, miss out on the list.

iOS 12

Apple released the first iOS 12 in September 2018, which featured better features than its predecessors, although they were not as ground-breaking as the previous releases. Its goal was to enhance the most commonly used applications and improve the user’s experience with iOS 11. 

You will need 2-3 GB of free space in your iPhone before you can download the update. You don’t have to panic because your system will tell you whether you have enough space. Unless there is room, iOS 12 will not download or install.

iOS 13

The thirteenth system software release isn’t as minor, taking up over 2GB depending on your type of iDevice. The upgrade may seem a little bigger because it boasts newer features and updates that weren’t available in the previous system, fixing bugs and improving app performance.

The software is a 2019 September major release from Apple, and users can’t get enough of it. It supports most iPhones, including the iPhone X Series, iPhone 11Series, iPhone 8, and 7. Unfortunately, the iPhone 6 and 6 Plus are incompatible with iOS 13.

iOS 14

The 2020 system software can take up 2- 3GB of your storage space without any extra for compressing files. You will need at least 4-5GB of storage to download it. The individual iOS seems more prominent than the older versions, possibly due to additional features. IOS 14 supports all iDevices compatible with iOS 13 and the newer iPhone 12 models.

iOS 15

The iOS 15 is one of the recent releases from Apple, the latest improvement being the 15.5 version in May 2022. Thanks to all the improved features, it is one of the heaviest systems to install. The release advances essential aspects of the iPhone like tweaks in privacy and security and Siri settings.

Following the official statements from Apple, the iOS 15 file weighs around 2.2 GB. Additionally, you will need a minimum of 5GB storage before accepting it to accommodate installation and setup. The process may also take up to 30 minutes if you have everything ready for download.

iOS 16

Apple announced the release of the newest iOS 16 in June 2022 at the WWDC. However, the update is still unavailable to the public, with experts speculating that it will drop in September 2022, around the same time iOS 15 launched last year.

Apple promised impressive new features, but there is currently not much about its size until its release. However, you can estimate that it may be heavier than iOS 15; therefore, you may need more than 2.5 GB of space.

iOS VersionCompatible DevicesSize
iOS 10iPhone 5 Series, iPhone 6 series, iPhone 7 series, iPhone SE1.5GB- 2.5GB
iOS 11iPhone SE, iPhone 5 series, iPhone 6 series, iPhone 7series, iPhone 8 series, iPhone 8, iPhone X2GB
iOS 12iPhone 5s, iPhone 6 series, iPhone 7 series, iPhone SE, iPhone 8 series, iPhone X series2GB-3GB
iOS 13iPhone SE, iPhone 6 series, iPhone 7 series, iPhone 8 series, iPhone X seriesOver 2GB
iOS 14iPhone SE, iPhone 6 series, iPhone 7 series, iPhone8 series, iPhone X series, iPhone 11 series2GB-3GB
iOS 15iPhone 6 series, iPhone SE, iPhone 7 series, iPhone 8 series, iPhone X series, iPhone 11 series, iPhone 12 series2.2 – 3GB
iOS Version to Compatible devices

Why Is iOS So Big?

The iOS ensures your iDevice functions smoothly, and Apple is always on top of it to guarantee that you run on the best and latest system. The software handles a lot, and users complain that they need too much room, explaining the questions about why the massive space is necessary. 

The iPhone operating systems take up an average space of 2.5GB of the total storage. However, the logs, caches, Siri, downloads records, applications, and other aspects need more space. Also, the iOS seems to grow bigger with each new release, and the latest version, 15, is a clear example, as it requires a whopping 5 and a half gigabytes of total storage. Still, updates within it generally consume less storage, amounting to about 700 megabytes.

IOS is the foundation that holds your iPhone, and you cannot operate the iPhone without it. The software doesn’t use massive space as many think, and other aspects consume storage. The operating system contains the various drives for particular hardware and services you want to execute. However, the iOS may take up massive room as the manufacturer adds more features to the software.

Sometimes, your iOS may be packed with ‘other data’ from the cache and your video and music streams. Siri voice and media download are common space depleters to watch out for if you have concerns about your iOS storage size.

The system software stores caches to help you enjoy smooth operations, especially when you need your previous activities to resurface or want to play back some of your best videos online.

The other data pile up and make your iOS appear more significant than it is. Fortunately, it is possible to shed off the extra weight and maintain the software’s actual size. Using excessive space may slow down the handset, making it inefficient to handle tasks as fast as it usually does. You can eliminate iOS-related files, browsing and download caches, mails, apps, and other unwanted data.

Auto deleting your text messages after some time may also help ease the pressure off your iOS. You can do the same to your emails and any file you don’t need and notice the enormous difference it makes. Social media may also impact your system data and make the iOS appear heavier. Deleting caches related to it and idle applications will ease the ‘other data’ effect on iOS.

Uninstalling inactive programs will create more space for system data. Ultimately, the iOS size will vary from one version to the other, and the different drives inside for various actions take up the most room in the software. In an iPhone, most operating systems hold about three gigabytes of storage, and it may be less if you update the program such that the new apps and system caches take up the remaining storage.


Thanks to updating the operating system, you can get significant security fixes and enjoy the most innovative Apple features. However, users don’t usually know how much storage is necessary before downloading any new iOS or even how much free space is available on their phones. You will need to prepare adequately before installation starting with freeing up space.

Remember that upgrades within primary versions are not as demanding as updating to a new iOS. Generally, you should free up to 5GB of data depending on the iOS and your type of device, but most systems require up to 3GB. If you don’t have that much space, you can delete some idle files for more room.

Bal Kang

Bal Kang is a technology expert based in the UK, with experience across a number of technology areas from phones, tablets, computers to gaming.

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