how can I update to big sur from osx 10.9.5?

rosé16 wrote:

how can I update to big sur from osx 10.9.5?

now my macbook version is 10.9.5.As it is a very low version I cant install apps such as viber,microsoft teams and manymore. Please instruct me how to fix this problem.

It never pays to get too far behind in the hardware or software— it only makes it more difficult moving forward.

OS X Mavericks 10.9.5 introduced in 2016—you may have to stair step your way up.

You neglect to say what exact Mac (year) you have ... it requires at least a late 2013 MBP to install the current Big Sur.

macOS Big Sur w/tech specs

https://support.apple.com/en-ca/HT201475

Tech specs—Big Sur

• MacBook (2015 or later)

• MacBook Air (2013 or later)

• MacBook Pro (Late 2013 or later)

• Mac mini (2014 or later)

• iMac (2014 or later)

• iMac Pro (2017 or later)

• Mac Pro (2013 or later)

All older macOS can be found on the back up servers:

https://support.apple.com/en-gb/HT211683

The Age of this computer will Govern what newer version of macOS it will Qualify to install. Use About this Mac from the Apple Icon on Desktop - the required Information will be there.

With the above information in-hand - follow this How to get old versions of macOS and verify what version this computer Qualifies to install. Make sure to use Only Safari to commence the download as Others may not work

Make a Time Machine Backup Before attempting. Notation - Mojave is the Last version to support 32 bit applications / extensions and Drivers. Catalina and Big Sur Only support 64 bit and there is no workaround.

Are there any AntiVirus, Disk Cleaner, Optimizers, Defrag, VPNs etc installed which should be removed as per Developers Instructions. They are useless, unneeded, cause havoc and interfere with the normal operation of the OS and may even Corrupt the OS requiring a Reinstallation.