Memory Upgrade For Mac

May 14, 2018 Carefully lift remove the memory module and place it in a static bag for storage. Depending on your type of Mac Pro, you make have either 4 memory slots or 8 memory slots (single CPU or dual CPU configurations respectively). The process is the same for both except for the number of modules. Upgrade the memory of your 27-inch 2019-2020 iMac up to 128GB. OWC memory kits are 100% Apple compatible and backed by a lifetime OWC warranty.

Memory Upgrade For Mac Mini 2018
Apple Laptop Memory Upgrade

Choose your iMac model

If you're not sure which iMac you have, you can identify your iMac and then select it from the list below.

27-inch

24-inch

21.5-inch

iMac (Retina 4K, 21.5-inch, 2019)*
iMac (Retina 4K, 21.5-inch, 2017)*
iMac (21.5-inch, 2017)*
iMac (21.5 inch, Mid 2014)*
iMac (21.5-inch, Late 2013)*
iMac (21.5-inch, Late 2012)*

20-inch

17-inch

* Memory is not removable by users on iMac (21.5-inch, Late 2012), iMac (21.5-inch, Late 2013), iMac (21.5-inch, Mid 2014), iMac (21.5-inch, 2017), iMac (Retina 4K, 21.5-inch, 2017), and iMac (Retina 4K, 21.5-inch, 2019). If the memory in one of these computers needs repair service, contact an Apple Retail Store or Apple Authorized Service Provider. If you’d like to upgrade the memory in one of these models, an Apple Authorized Service Provider can help. Before you schedule an appointment, confirm that the specific Apple Authorized Service Provider offers memory upgrade services.

Memory in iMac (21.5-inch, Late 2015), and iMac (Retina 4K, 21.5-inch, Late 2015) is not upgradeable.

iMac (Retina 5K, 27-inch, 2020)

Get memory specifications for iMac (Retina 5K, 27-inch, 2020), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Number of memory slots	4
Base memory	8GB (2 x 4GB DIMMs)
Maximum memory	128GB (4 x 32GB DIMMs)

For optimal memory performance, DIMMs should be the same capacity, speed, and vendor. Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

PC4-21333
Unbuffered
Nonparity
260-pin
2666MHz DDR4 SDRAM

If you have mixed capacity DIMMs, see the install memory section for installation recommendations.

iMac (Retina 5K, 27-inch, 2019)

Get memory specifications for iMac (Retina 5K, 27-inch, 2019), then learn how to install memory in this model.

Memory Upgrade For Mac Mini 2018

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Number of memory slots	4
Base memory	8GB (2 x 4GB DIMMs)
Maximum memory	64GB (4 x 16GB DIMMs)

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

PC4-21333
Unbuffered
Nonparity
260-pin
2666MHz DDR4 SDRAM

iMac (Retina 5K, 27-inch, 2017)

Get memory specifications for iMac (Retina 5K, 27-inch, 2017), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Number of memory slots	4
Base memory	8GB (2 x 4GB DIMMs)
Maximum memory	64GB (4 x 16GB DIMMs)

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

PC4-2400 (19200)
Unbuffered
Nonparity
260-pin
2400MHz DDR4 SDRAM

iMac (Retina 5K, 27-inch, Late 2015)

Get memory specifications for iMac (Retina 5K, 27-inch, Late 2015), then learn how to install memory in this model.

Memory specifications

This iMac model features Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Number of memory slots	4
Base memory	8GB
Maximum memory	32GB

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

PC3-14900
Unbuffered
Nonparity
204-pin
1867MHz DDR3 SDRAM

For these 27-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

iMac (Retina 5K, 27-inch, Mid 2015)
iMac (Retina 5K, 27-inch, Late 2014)
iMac (27-inch, Late 2013)
iMac (27-inch, Late 2012)

Memory specifications

These iMac models feature Synchronous Dynamic Random-Access Memory (SDRAM) slots on the rear of the computer near the vents with these memory specifications:

Number of memory slots	4
Base memory	8GB
Maximum memory	32GB

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

PC3-12800
Unbuffered
Nonparity
204-pin
1600MHz DDR3 SDRAM

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

Disconnect the power cord and all other cables from your computer.
Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
Open the memory compartment door by pressing the small grey button located just above the AC power port:
The memory compartment door will open as the button is pushed in. Remove the compartment door and set it aside:
A diagram on the underside of the compartment door shows the memory cage levers and the orientation of the DIMM. Locate the two levers on the right and left sides of the memory cage. Push the two levers outward to release the memory cage:
After the memory cage is released, pull the memory cage levers toward you, allowing access to each DIMM slot.
Remove a DIMM by pulling the module straight up and out. Note the location of the notch on the bottom of the DIMM. When reinstalling DIMMs, the notch must be oriented correctly or the DIMM won't fully insert:
Replace or install a DIMM by setting it down into the slot and pressing firmly until you feel the DIMM click into the slot. When you insert a DIMM, make sure to align the notch on the DIMM to the DIMM slot. Find your model below for specific installation instructions and notch locations:
- iMac (Retina 5K, 27-inch, 2020) DIMMs have a notch on the bottom, slightly left of the middle. If your DIMMs are mixed in capacity, minimize the capacity difference between Channel A (slots 1 and 2) and Channel B (slots 3 and 4) when possible.
- iMac (Retina 5K, 27-inch, 2019) DIMMs have a notch on the bottom, slightly left of the middle:
- iMac (27-inch, Late 2012) and iMac (Retina 5K, 27-inch, 2017) DIMMs have a notch on the bottom left:
- iMac (27-inch, Late 2013) and iMac (Retina 5K, 27-inch, Late 2014, Mid 2015, and Late 2015) DIMMs have a notch on the bottom right:
After you install all of your DIMMs, push both memory cage levers back into the housing until they lock into place:
Replace the memory compartment door. You don't need to press the compartment door release button when replacing the compartment door.
Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

Your iMac performs a memory initialization procedure when you first turn it on after upgrading memory or rearranging DIMMs. This process can take 30 seconds or more, and the display of your iMac remains dark until it's finished. Make sure to let the memory initialization complete.

For these 27-inch and 21.5-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

iMac (27-inch, Mid 2011)
iMac (21.5-inch, Mid 2011)
iMac (27-inch, Mid 2010)
iMac (21.5-inch, Mid 2010)
iMac (27-inch, Late 2009)
iMac (21.5-inch, Late 2009)

Memory specifications

Number of memory slots	4
Base memory	4GB (but is configured to order)
Maximum memory	16GB For iMac (Late 2009), you can use 2GB or 4GB RAM SO-DIMMs of 1066MHz DDR3 SDRAM in each slot. For iMac (Mid 2010) and iMac (Mid 2011), use 2GB or 4GB RAM SO-DIMMs of 1333MHz DDR3 SDRAM in each slot.

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

iMac (Mid 2011)	iMac (Mid 2010)	iMac (Late 2009)
PC3-10600	PC3-10600	PC3-8500
Unbuffered	Unbuffered	Unbuffered
Nonparity	Nonparity	Nonparity
204-pin	204-pin	204-pin
1333MHz DDR3 SDRAM	1333MHz DDR3 SDRAM	1066MHz DDR3 SDRAM

i5 and i7 Quad Core iMac computers come with both top memory slots populated. These computers will not start up if only a single DIMM is installed in any bottom slot; these computers should operate normally with a single DIMM installed in any top slot.

Core Duo iMac computers should operate normally with a single DIMM installed in any slot, top or bottom. ('Top' and 'bottom' slots refer to the orientation of the slots in the pictures below. 'Top' refers to the slots closest to the display; 'bottom' refers to the slots closest to the stand.)

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

Disconnect the power cord and all other cables from your computer.
Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
Using a Philips screwdriver, remove the RAM access door in the bottom of your computer:
Remove the access door and set it aside.
Untuck the tab in the memory compartment. If you're replacing a memory module, gently pull the tab to eject any installed memory module:
Insert your new or replacement SO-DIMM into the empty slot, noting the orientation of the keyway of the SO-DIMM as shown below.
After you insert it, press the DIMM up into the slot. There should be a slight click when you seat the memory correctly:
Tuck the tabs above the memory DIMMs, and reinstall the memory access door:
Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

For these 24-inch and 20-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

iMac (24-inch, Early 2009)
iMac (20-inch, Early 2009)
iMac (24-inch, Early 2008)
iMac (20-inch, Early 2008)
iMac (24-inch Mid 2007)
iMac (20-inch, Mid 2007)

Memory specifications

These iMac computers have two side-by-side Synchronous Dynamic Random-Access Memory (SDRAM) slots in the bottom of the computer.

The maximum amount of random-access memory (RAM) you can install in each computer is:

Computer	Memory Type	Maximum Memory
iMac (Mid 2007)	DDR2	4GB (2x2GB)
iMac (Early 2008)	DDR2	4GB (2x2GB)
iMac (Early 2009)	DDR3	8GB (2x4GB)

You can use a 1GB or 2GB RAM module in each slot for iMac (Mid 2007) and iMac (Early 2008). Use 1GB, 2GB, or 4GB modules in each slot for the iMac (Early 2009).

Use Small Outline Dual Inline Memory Modules (SO-DIMM) that meet all of these criteria:

iMac (Mid 2007)	iMac (Early 2008)	iMac (Early 2009)
PC2-5300	PC2-6400	PC3-8500
Unbuffered	Unbuffered	Unbuffered
Nonparity	Nonparity	Nonparity
200-pin	200-pin	204-pin
667MHz DDR2 SDRAM	800MHz DDR2 SDRAM	1066MHz DDR3 SDRAM

DIMMs with any of the following features aren't supported:

Registers or buffers
PLLs
Error-correcting code (ECC)
Parity
Extended data out (EDO) RAM

Installing memory

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After your iMac cools down, follow these steps:

Disconnect the power cord and all other cables from your computer.
Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
Using a Philips screwdriver, remove the RAM access door in the bottom of the computer:
Remove the access door and set it aside.
Untuck the tab in the memory compartment. If you're replacing a memory module, untuck the tab and pull it to eject any installed memory module:
Insert your new or replacement RAM SO-DIMM into the empty slot, noting the orientation of the keyway of the SO-DIMM as shown above.
After you insert it, press the DIMM up into the slot. There should be a slight click when you seat the memory correctly.
Tuck the tabs above the memory DIMMs, and reinstall the memory access door:
Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

For these 20-inch and 17-inch models

Get memory specifications for the following iMac models, then learn how to install memory in them:

iMac (20-inch Late 2006)
iMac (17-inch, Late 2006 CD)
iMac (17-inch, Late 2006)
iMac (17-inch, Mid 2006)
iMac (20-inch, Early 2006)
iMac (17-inch, Early 2006)

Memory specifications

Number of memory slots	2
Base memory	1GB	Two 512MB DIMMs; one in each of the memory slots	iMac (Late 2006)
	512MB	One DDR2 SDRAM installed into the top slot	iMac (17-inch Late 2006 CD)
	512MB	Two 256MB DIMMs; one in each of the memory slots	iMac (Mid 2006)
	512MB	One DDR2 SDRAM installed into the top slot	iMac (Early 2006)
Maximum memory	4GB	2 GB SO-DIMM in each of the two slots*	iMac (Late 2006)
Maximum memory	2GB	1GB SO-DIMM in each of the two slots	iMac (17-inch Late 2006 CD) iMac (Early 2006)
Memory card specifications	Compatible: - Small Outline Dual Inline Memory Module (DDR SO-DIMM) format - PC2-5300 - Nonparity - 200-pin - 667 MHz - DDR3 SDRAM		Not compatible: - Registers or buffers - PLLs - ECC - Parity - EDO RAM

For best performance, fill both memory slots, installing an equal memory module in each slot.
*iMac (Late 2006) uses a maximum of 3 GB of RAM.

Installing memory in the bottom slot

The internal components of your iMac can be warm. If you've been using your iMac, wait ten minutes after shutting it down to let the internal components cool.

After you shut down your iMac and give it time to cool, follow these steps:

Disconnect the power cord and all other cables from your computer.
Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
Using a Phillips screwdriver, remove the RAM access door on the bottom of the iMac and set it aside:
Move the DIMM ejector clips to their fully open position:
Insert your RAM SO-DIMM into the bottom slot, keeping in mind the orientation of the keyed SO-DIMM:
After you insert it, press the DIMM up into the slot with your thumbs. Don't use the DIMM ejector clips to push in the DIMM, as this might damage the SDRAM DIMM. There should be a slight click when you seat the memory fully.
Close the ejector clips:
Reinstall the memory access door:
Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

Replacing memory in the top slot

After you shut down your iMac and give it time to cool, follow these steps:

Disconnect the power cord and all other cables from your computer.
Place a soft, clean towel or cloth on the desk or other flat surface to prevent scratching the display.
Hold the sides of the computer and slowly lay the computer face-down on the towel or cloth.
Using a Phillips screwdriver, remove the RAM access door on the bottom of the iMac and set it aside:
Pull the two levers on each side of the memory compartment to eject the memory module that's already installed:
Remove the memory module from your iMac as shown below:
Insert your RAM SO-DIMM into the top slot, noting the orientation of the keyed SO-DIMM:
After you insert it, press the DIMM up into the slot with your thumbs. Don't use the DIMM ejector clips to push in the DIMM, as this might damage the SDRAM DIMM. There should be a slight click when you seat the memory fully.
Close the ejector clips:
Reinstall the memory access door:
Place the computer in its upright position. Reconnect the power cord and all other cables to the computer, then start up the computer.

If your iMac makes a tone after you install memory

iMac models introduced before 2017 might make a warning sound when you start up after installing or replacing memory:

One tone, repeating every five seconds signals that no RAM is installed.
Three successive tones, then a five-second pause (repeating) signals that RAM doesn't pass a data integrity check.

Apple Laptop Memory Upgrade

If you hear these tones, confirm that the memory you installed is compatible with your iMac and that it's installed correctly by reseating the memory. If your Mac continues to make the tone, contact Apple Support.

Confirm that your iMac recognizes its new memory

After you install memory, you should confirm that your iMac recognizes the new RAM by choosing Apple () menu > About This Mac.

The window that appears lists the total memory, including the amount of memory that originally came with the computer plus the newly added memory. If all the memory in the iMac has been replaced, it lists the new total of all installed RAM.

For detailed information about the memory installed in your iMac, click System Report. Then choose Memory under the Hardware section in the left side of System Information.

If your computer doesn't recognize the memory or doesn't start up correctly, confirm that the RAM you installed is compatible with your iMac and that it's installed correctly by reseating the memory. If you continue to have issues with the memory in your iMac, contact Apple Support.

When you upgrade to macOS Catalina, you get more of everything you love about Mac. Experience dedicated apps for music, TV, and podcasts. Smart new features in the apps you use every day. And Sidecar, which lets you use iPad as a second Mac display. Best of all, upgrading is free and easy.

Chances are, your Mac can run macOS Catalina.

Mac computers with Metal-capable graphics processors (GPUs) can upgrade to macOS Catalina.

Make sure you’re ready to upgrade.

Before you upgrade, we recommend that you back up your Mac. Then, if your Mac is running OS X Mavericks 10.9 or later, you can upgrade directly to macOS Catalina.

Upgrading is free. And easier than you think.

Upgrading from macOS Mojave?

Go to Software Update in System Preferences to find the macOS Catalina upgrade. Click Upgrade Now and follow the onscreen instructions to begin your upgrade. If you don’t have broadband access, you can upgrade your Mac at any Apple Store.

Upgrading from an older version of macOS?

If you’re running High Sierra (10.13), Sierra (10.12), or El Capitan (10.11), upgrade to macOS Catalina from the App Store. If you’re running Lion (10.7) or Mountain Lion (10.8), you will need to upgrade to El Capitan (10.11) first. If you don’t have broadband access, you can upgrade your Mac at any Apple Store.

OS X 10.9 or later
4GB of memory
12.5GB of available storage (OS X El Capitan 10.11.5 or later)*

Some features require an Apple ID; terms apply.
Some features require a compatible internet service provider; fees may apply.

For details about your Mac model, click the Apple icon at the top left of your screen and choose About This Mac. These Mac models are compatible with macOS Catalina:

MacBook (Early 2015 or newer)
MacBook Air (Mid 2012 or newer)
MacBook Pro (Mid 2012 or newer)
Mac mini (Late 2012 or newer)

iMac (Late 2012 or newer)
iMac Pro (2017)
Mac Pro (Late 2013 or newer)

Siri

Requires a broadband internet connection and microphone (built-in or external).

Hey Siri

Supported by the following Mac models:

MacBook Pro (2018 or newer)
MacBook Air (2018 or newer)
iMac Pro

Dictation, Voice Control, and Voice Memos

Requires a microphone (built-in or external).

Spotlight Suggestions

Requires a broadband internet connection.

Gestures

Requires a Multi-Touch trackpad, Force Touch trackpad, Magic Trackpad, or Magic Mouse.

Force Touch gestures require a Force Touch trackpad.

VoiceOver gestures require a Multi-Touch trackpad, Force Touch trackpad, or Magic Trackpad.

Photo Booth

Requires a FaceTime or iSight camera (built-in or external), or USB video class (UVC) camera.

FaceTime

Audio calls require a microphone (built-in or external) and broadband internet connection.

Video calls require a built-in FaceTime camera, an iSight camera (built-in or external), or a USB video class (UVC) camera; and broadband internet connection.

Apple TV

High Dynamic Range (HDR) video playback is supported by the following Mac models:

MacBook Pro (2018 or newer)
iMac Pro (2017)
Mac Pro (2019) with Pro Display XDR

Dolby Atmos soundtrack playback is supported by the following Mac models:

MacBook Air (2018 or newer)
MacBook Pro (2018 or newer)

Sidecar

Supported by the following Mac models:

MacBook (2016 or newer)
MacBook Air (2018 or newer)
MacBook Pro (2016 or newer)
Mac mini (2018 or newer)
iMac (late 2015 or newer)
iMac Pro (2017 or newer)
Mac Pro (2019)

Supported by all iPad models with Apple Pencil support:

12.9-inch iPad Pro
11-inch iPad Pro
10.5-inch iPad Pro
9.7-inch iPad Pro
iPad (6th generation or later)
iPad mini (5th generation)
iPad Air (3rd generation)

Continuity Camera

Requires an iPhone or iPad with a Lightning connector and iOS 12 or later.

Continuity Sketch and Continuity Markup

Requires an iPhone with iOS 13 or an iPad with iPadOS.

Handoff

Requires an iPhone or iPad with a Lightning connector and iOS 8 or later.

Instant Hotspot

Requires an iPhone or iPad with cellular connectivity, a Lightning connector, and iOS 8.1 or later. Requires Personal Hotspot service through your carrier.

Universal Clipboard

Requires an iPhone or iPad with a Lightning connector and iOS 10 or later.

Auto Unlock

Supported by Mac models introduced in mid 2013 or later.

Requires an Apple Watch with watchOS 3 or later or an iPhone 5 or later.

Approve with Apple Watch

Supported by Mac models introduced in mid 2013 or later.

Requires an Apple Watch with watchOS 6 or later or an iPhone 6s or later with iOS 13.

Apple Pay on the Web

Requires MacBook Pro with Touch Bar, an iPhone 6 or later with iOS 10 or later, or an Apple Watch with watchOS 3 or later.

Phone Calling

Requires an iPhone with iOS 8 or later and an activated carrier plan.

SMS

Requires an iPhone with iOS 8.1 or later and an activated carrier plan.

Home

Requires an iPhone with iOS 12 or later and a configured Home app.

AirDrop

AirDrop to iOS and iPadOS devices requires an iPhone or iPad with a Lightning connector and iOS 7 or later.

AirPlay

AirPlay Mirroring requires an Apple TV (2nd generation or later).

AirPlay for web video requires an Apple TV (2nd generation or later).

Peer-to-peer AirPlay requires a Mac (2012 or later) and an Apple TV (3rd generation rev A, model A1469 or later) with Apple TV software 7.0 or later.

Time Machine

Requires an external storage device (sold separately).

Power Nap

Supported by the following Mac models:

MacBook (Early 2015 or newer)
MacBook Air (Mid 2012 or newer)
MacBook Pro with Retina display (Mid 2012 or newer)
Mac mini (Late 2012 or newer)
iMac (Late 2012 or newer)
iMac Pro (2017)
Mac Pro (Late 2013 or newer)

Boot Camp

Allows Boot Camp installations of Windows 10 on supported Mac models.

Exchange Support

Requires Microsoft Office 365, Exchange 2016, Exchange 2013, or Exchange Server 2010. Installing the latest Service Packs is recommended.

Windows Migration

Supports OS X 10.7 or later and Windows 7 or later.

App Store

Available only to persons age 13 or older in the U.S. and many other countries and regions.

Apple Books
Apple News
App Store
Automator
Calculator
Calendar
Chess
Contacts
Dictionary
DVD Player
FaceTime
Find My
Font Book
Home
Image Capture
Launchpad
Mail
Maps

Messages
Mission Control
Music
Notes
Photo Booth
Photos
Podcasts
Preview
QuickTime Player
Reminders
Safari
Siri
Stickies
Stocks
System Preferences
TextEdit
Time Machine
TV
Voice Memos

Activity Monitor
AirPort Utility
Audio MIDI Setup
Bluetooth File Exchange
Boot Camp Assistant
ColorSync Utility
Console
Digital Color Meter
Disk Utility

Grapher
Keychain Access
Migration Assistant
Screenshot
Screen Time
Script Editor
Sidecar
System Information
Terminal
VoiceOver Utility

Arabic
Catalan
Croatian
Simplified Chinese
Traditional Chinese
Traditional Chinese (Hong Kong)
Czech
Danish
Dutch
English (Australia)
English (UK)
English (U.S.)
Finnish
French
French (Canada)
German
Greek
Hebrew
Hindi
Hungarian

Indonesian
Italian
Japanese
Korean
Malay
Norwegian
Polish
Brazilian Portuguese
Portuguese
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Spanish
Spanish (Latin America)
Swedish
Thai
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Ukrainian
Vietnamese