iMac 21.5-inch Late 2012, 2013 and Mid 2014 Repair and Upgrades

For a 21.5-inch iMac from Late 2012 to Mid 2014 (A1418), the upgrade that matters is replacing its 5400rpm hard drive with an SSD, from $599. On the 2012 and 2013 models, 16GB of RAM costs from $249 extra at the same time because the display is already off; the Mid 2014 has 8GB soldered to the board, and that cannot change. Apple's macOS support ends at Catalina (2012–2013) or Big Sur (2014), and OpenCore Legacy Patcher takes all of them to Sequoia, from $249.

Working out which 21.5-inch model you have

Every model here has A1418 printed on the underside of the stand, but so do the 21.5-inch iMacs from 2015 and 2017. That number gives you the size and design, not the year. For the year, use one of these:

• About This Mac (Apple menu) gives the full name, such as "iMac (21.5-inch, Late 2013)".
• System Information lists the Model Identifier under Hardware Overview (hold Option while opening the Apple menu to find it): iMac13,1 for Late 2012, iMac14,1 for the Late 2013 2.7GHz and iMac14,4 for Mid 2014.
• The serial number, printed beside the A-number, identifies the exact model at checkcoverage.apple.com.

Two identifiers confuse people. EveryMac lists the faster Late 2013 models (2.9GHz and 3.1GHz, GeForce graphics) as iMac14,3, yet the patcher's model table files iMac14,3 under the 27-inch Late 2013, and Apple's identification page lists only iMac14,1. The education-only Early 2013 appears as iMac13,1 at EveryMac and iMac13,3 in the patcher's list. If the identifier surprises you, go by the About This Mac name and the serial, and quote both when you contact us.

Specifications by model

Upgrades: what can be done and what it costs

SSD from $599 (display removal)

The 5400rpm laptop-size hard drive is what holds these iMacs back, and newer macOS makes it worse: APFS, the file system Apple now uses, fragments on hard drives and slows over weeks and months. An SSD in the 2.5-inch SATA bay fixes it. Through our iMac SSD upgrade, 500GB costs from $599 and 1TB from $699, with your files moved across and macOS set up. Reaching the bay means slicing through the strips that hold the display, whose glass and LCD are one fused unit, and resealing it with fresh adhesive.

Whether a blade SSD connector is also present depends on the year:

• Late 2013: always there, even on hard-drive-only machines, and it is PCIe, so an NVMe SSD can go in with an adapter. The Mac must be on High Sierra or later for that, which is why we update it first.
• Late 2012, Early 2013 and Mid 2014: only if the iMac was bought with a Fusion Drive or SSD. On a hard-drive-only unit the socket is not on the board, and the SSD goes in the 2.5-inch bay. The Late 2012 blade slot is SATA-only, so NVMe will not work in it.

A Fusion Drive is two drives presented as one. Replace either half and macOS shows two disks, and Apple's reset command deletes everything, so we copy your data off first.

RAM: 2012 and 2013 only (involved)

On the Late 2012, Early 2013 and Late 2013, the two DDR3 slots (1600MHz on the Late 2012 and Late 2013) sit behind the logic board. Apple calls the memory not removable by users, and iFixit's teardown notes you have to unglue the screen and remove the logic board to reach it. The limit is 16GB. Through our iMac RAM upgrade it is from $449 on its own including 16GB, or from $249 extra with an SSD, when the board is already out. That combined visit is the only time we would suggest it.

The Mid 2014 is a different machine inside. Its 8GB is LPDDR3 soldered to the logic board, and no one can add more.

Other repairs

Screen replacement for these non-Retina models is from $499, the power supply from $399, a fan clean with thermal service from $249, and board-level logic board repair starts from $449. More on our screen replacement and power supply and board repairs pages.

macOS support and the patcher

Apple stopped at Catalina 10.15 for the 2012 and 2013 models and at Big Sur 11 for the Mid 2014. On Catalina, current Firefox and Zoom still run, but Chrome needs Ventura and Microsoft 365 no longer updates. Big Sur is little better: Chrome 138 was its last version, Safari is stuck on an older release, and Microsoft 365 updates have ended.

With OpenCore Legacy Patcher, every model here can run anything from Big Sur up to Sequoia 15; our install with patches and post-install checks is from $249. From Ventura, the patcher treats all of these GPUs as Legacy Metal, whether Nvidia Kepler (Late 2012, faster Late 2013) or Intel integrated graphics (the rest). What that means in use:

• Live Text and Photos face detection are disabled by default.
• On Sonoma and later, DRM-protected video in Safari fails on most of these GPUs.
• Kepler machines on Sequoia can find Software Update hanging and dynamic wallpapers broken.
• The Ivy Bridge processors in the Late 2012 and Early 2013 lack AVX2, which some newer apps need; the Haswell chips in the Late 2013 and Mid 2014 have it.

Each macOS update wipes the patches, which then have to be installed again, and a patched Mac runs with some protections lowered; newer macOS on an old iMac explains the trade-offs. On the Mid 2014, 8GB clears Sequoia's 3GB minimum, but newer macOS is heavier to run and that memory can never grow.

Target Display Mode

Apple lists any iMac introduced in 2012, 2013 or mid 2014 as able to act as a Thunderbolt display for another Mac, so every model on this page qualifies. Press Command-F2 on the iMac. The limits are on software: the iMac must be on High Sierra 10.13.6 or earlier, and the other Mac must date from 2019 or earlier and run Catalina or earlier. An iMac updated to Catalina or Big Sur, or patched, falls outside what Apple states.

Known problems on these models

• A slow, ageing 5400rpm drive. The reason the SSD comes first.
• Fusion Drive halves out of step. After one part is replaced, the Mac shows two drives instead of one.
• Everything is behind a glued display. iFixit scored the Late 2012 21.5-inch 3 out of 10 for repairability.
• No Apple repair program to fall back on. The confirmed programs of this era covered 27-inch hinges, 27-inch 3TB drives and the 2011 27-inch graphics card, not these 21.5-inch models, and all of them have ended.

What is worth doing on a 21.5-inch 2012–2014

Our September 2026 Gumtree check found too few listings of these exact models to quote a figure. The nearest guides: 27-inch Late 2012 and 2013 iMacs were asking about $220 (median), and the 21.5-inch Retina 4K 2017 about $500. A smaller non-Retina machine of the same age is unlikely to fetch more than that 27-inch, so treat yours as worth a couple of hundred dollars.

On a 2012 or 2013, one visit from $848 cures the slow drive and lifts memory to 16GB. That is about a third of a new base M4 iMac ($2,399) but roughly four times what the machine is likely to fetch, so do it only if you want to keep this iMac. Be more careful still with the Mid 2014. An SSD makes it far quicker, but the 1.4GHz dual-core chip and fixed 8GB stay, so it suits browsing, email and documents. The SSD alone, from $599, costs more than a used 21.5-inch 4K 2017 at around $500, which is a better home for the money than spending from $848 on an SSD and the patcher here (see 21.5-inch 2015–2019). With a dead screen or board, get your files back through data recovery (from $249) and move on. Our iMac repair cost guide lists every price.

iMacs are drop-off only: bring yours to our workshop near Castle Hill, open Monday to Saturday from 8am to 6pm. A quote by phone costs nothing, the turnaround is usually one to two business days for SSD and RAM work when parts are in stock, and all work carries a 12-month warranty. Other generations: 2009–2011 iMacs, the 27-inch Late 2012 and 2013, and all Intel iMac repairs and upgrades.

Call 0400 454 859

Questions

Can you upgrade the RAM in a 2014 21.5-inch iMac?

No. The Mid 2014 21.5-inch (iMac14,4) has 8GB of LPDDR3 soldered to the logic board and no memory slots, so it cannot be upgraded by anyone. An SSD still cures the slow hard drive, but from $599 it costs more than a used 21.5-inch 4K 2017 is advertised for, so fit one only if you want to keep this iMac. If 8GB is not enough for the way you work, a later model with more memory is the better buy.

How much RAM can a Late 2013 21.5-inch iMac take?

16GB, in two slots of 1600MHz DDR3 SO-DIMM. The slots are behind the logic board, so the screen must be removed and the board lifted out. That makes it a job from $449 on its own, including 16GB, or from $249 extra when we are already inside for an SSD upgrade.

Does my 21.5-inch iMac have a blade SSD slot?

The Late 2013 always does, and it is PCIe. The Late 2012, Early 2013 and Mid 2014 have one only if the iMac was ordered with a Fusion Drive or SSD; hard-drive-only units do not have the connector at all. Either way an SSD can go in the 2.5-inch drive bay, so a missing blade slot does not stop the upgrade.

Can a 21.5-inch Late 2013 iMac run macOS Sequoia?

Yes, through OpenCore Legacy Patcher, although Apple's support stopped at Catalina. The patcher classes its graphics as Legacy Metal, meaning Live Text is off by default and DRM video in Safari is unreliable on newer versions. Its Haswell chip supports AVX2, so apps that demand it will run. Fit an SSD first, because modern macOS on a 5400rpm drive is painful. Our install costs from $249.

Why does my 21.5-inch Late 2013 iMac say iMac14,3?

EveryMac lists the 2.9GHz and 3.1GHz 21.5-inch Late 2013 models with GeForce GT 750M graphics as iMac14,3. Other references, including the patcher's own model table, file iMac14,3 under the 27-inch, and Apple's own identification page mentions only iMac14,1 for this model. If About This Mac says 21.5-inch, trust that, and mention the identifier when you book so we plan the right patches.

Can I use a 21.5-inch 2013 iMac as a second screen?

Apple supports Target Display Mode on 21.5-inch iMacs introduced in 2012, 2013 and mid 2014, over Thunderbolt. Apple only supports it while the iMac runs High Sierra 10.13.6 or an earlier version, with the source Mac introduced no later than 2019 and running no later than Catalina. If you have updated the iMac to Catalina or patched it, Apple's stated requirement is no longer met.