Secure wipe HD before resale - best approach on 2011 MacBook Air?

[MitzEclipse]

Hi all

I have a 2011 MacBook Air I want to do a secure wipe before reselling.

I currently have High Sierra installed. What's the best way to securely wipe the data then reinstall a new OS? I tried to wipe by holding Option during restart but I didn't get the Disk Utility at start up - not sure what I'm doing wrong here? This would then in theory install Lion then I would upgrade from there. However, I want to ensure I am securely wiping everything.

I've done this with boot utilities on PCs but not sure on the Mac. Thanks in advance.

 

[MacCheetah3]

What to do before you sell, give away, trade in, or recycle your Mac - Apple Support

Reset your Mac to factory settings to prepare it for a new owner.

support.apple.com

 

[Fishrrman]

BEFORE YOU GO FURTHER, you want to SIGN OUT of iCloud and iTunes.
Also, turn off "Find my Mac" if you have it enabled (or if it can be turned off, don't know, never used it).
But leaving this stuff "on" can mess things up for a new owner.

Then...

Boot to INTERNET recovery:
Command-OPTION-R

You'll need your wifi password, and the internet utilities will take a while to load.

When you get to the utilities, open disk utility.
Check to see if there's a "view" menu.
IF THERE IS, choose "show all devices"
(if there IS NOT, don't worry about it).

Now... on the left...
The top line represents the physical disk inside.
Click on it and then click erase.
For High Sierra, I suggest "Mac OS extended with journaling enabled, GUID partition format".

Does the drive erase now?
If it does, quit disk utility and open the OS installer, and start "clicking through"...