Yes, if you format the drive: the operation erases everything permanently. Back up first. A reinstall over the existing system, without formatting, should in principle keep your data, but a backup is still essential.

Guide · macOS

Reinstall macOS over the Internet: start Recovery, format the SSD, reinstall everything

Q: Which key boots into Recovery?

On an Intel Mac: Cmd+R for the version already installed, Cmd+Option+R for Internet Recovery (the most recent compatible version), Cmd+Shift+Option+R for the original version. Hold the keys from the moment you power on, until the globe appears.

Q: Which format should I choose: APFS or Mac OS Extended?

APFS for macOS High Sierra and later, that's the recommended choice. Mac OS Extended (Journaled) only for an older version. The scheme must be GUID Partition Map.

Q: How long does it take?

Formatting is almost instant. The installation takes from 30 minutes to over an hour depending on the connection and the Mac, with several restarts. Keep the Mac plugged into the mains.

Sluggish Mac, a swapped drive, a resale or simply the urge to start fresh: reinstalling over the Internet is the simplest way to get macOS back in shape, with no USB stick. Your Mac downloads everything from Apple’s servers. Here’s how to do it, step by step.

Place du Mac— Tutorial— 21 July 2026— 8 min read

The essentials

It all comes down to three moves: boot into Recovery (a keyboard combination at startup), format the drive as APFS via Disk Utility, then run “Reinstall macOS”. No USB stick, no third-party software — just a good Wi-Fi connection and a little patience. This guide is for Intel-based Macs, including the 2013-2015 MacBooks.

Read this before you start

Three essential precautions

Back up your data. Formatting erases everything on the drive, permanently. Copy anything that matters before you begin.
Plug in the power and make sure you have a stable Wi-Fi connection: the installer downloads macOS and must not be interrupted.
Intel Macs. The key combinations below apply to Intel-based Macs (Apple Silicon Macs start up differently, by holding down the power button).

Step1

Boot into Internet Recovery

Shut the Mac down completely (Apple menu › Shut Down). Switch it on and, immediately, hold down one of the combinations below until you see a spinning globe and the message “Starting Internet Recovery”. Then connect to Wi-Fi; the macOS Utilities window will eventually appear.

Tip: if the drive has been removed or is empty, the Mac often falls back to Internet Recovery on its own.

The three combinations

Which key combination should you choose?

Hold the keys down the moment you power on, before the logo. For a new or freshly formatted drive, go for Internet Recovery.

⌘ Cmd+R

Local Recovery

Reinstalls the latest version of macOS already installed on this Mac (from the local recovery partition).

⌘ Cmd+⌥ Option+R

Internet Recovery

Installs the most recent version compatible with your Mac. Best after a drive swap or a format.

⌘ Cmd+⇧ Shift+⌥ Option+R

Original version

Installs the version of macOS that shipped with the Mac (or the closest one still available).

Step2

Format the internal SSD

In the macOS Utilities window, open Disk Utility. The tricky bit: be sure to select the whole physical drive, not just a volume inside it.

Choose Disk Utility, then Continue.
At the top, click View › Show All Devices.
In the left-hand column, select the internal drive (the “parent” line, e.g. APPLE SSD…), not the “Macintosh HD” sub-volume.
Click Erase and fill in: Name = Macintosh HD; Format = APFS (or Mac OS Extended (Journaled) for versions earlier than High Sierra); Scheme = GUID Partition Map.
Confirm with Erase. A few seconds is all it takes. Then quit Disk Utility to return to macOS Utilities.

The GUID scheme isn’t showing? That means you’ve selected a volume, not the whole drive: go back to step c.

Step3

Start the macOS installation

Back in macOS Utilities, all that’s left is to reinstall the system. The Mac downloads macOS from Apple, then installs it on the drive you’ve just formatted.

Choose Reinstall macOS, then Continue.
Accept the terms, then select the formatted drive (Macintosh HD) as the destination.
Click Install, then let it run: allow anything from 30 minutes to over an hour depending on your connection. The Mac restarts several times; the screen may go black at times. Don’t cut the power.
At the end, the Mac boots into the setup assistant. To keep it: follow the assistant. To sell it on: stop here (⌘ Cmd+Q › Shut Down), and the next owner will arrive at a fresh system.

Good to know: a progress bar frozen for several minutes is normal — the download carries on in the background.

If something goes wrong

Stuck? The most common cases

The globe doesn’t appear. Check that you’re holding the keys from the moment you power on, before any logo. Try a different Wi-Fi network: some corporate networks block Recovery.
An error code with an exclamation mark during Internet startup usually points to a network issue: move closer to the router and try again.
The drive doesn’t appear in Disk Utility: turn on Show All Devices. If it’s still missing on a new NVMe-type SSD, it may be a case of incompatible firmware (see our guide on NVMe and 2013-2015 MacBooks).
An error during the erase? Simply run it again: it’s common and nothing to worry about.

The myth to bust What many people believe — and it’s wrong

“Reinstalling macOS is complicated and risky.”

Wrong. Everything is built into the Mac: no USB stick to prepare, no awkward downloads. Three steps are all it takes — boot into Recovery, format, reinstall — and the system downloads itself straight from Apple. The one real precaution: back up your data first, since formatting wipes the drive.

If there’s one thing to remember

Boot, format, reinstall: three moves, zero USB stick.

Internet Recovery does all the work: Cmd+Option+R to boot, Disk Utility to format as APFS (GUID scheme), then “Reinstall macOS”. Back up first, keep the Mac plugged in, and let it get on with it. In any doubt? We’ll guide you through it.

Take action

Need a drive before reinstalling?

A faster or larger SSD transforms an ageing Mac. Browse our drives tested for Mac, with a 2-year warranty.

See SSDs for Mac → NVMe SSD: the firmware question →

Frequently asked questions

Reinstalling macOS over the Internet: your questions

Which key boots into Recovery?

On an Intel Mac: Cmd+R for the version already installed, Cmd+Option+R for Internet Recovery (the most recent compatible version), Cmd+Shift+Option+R for the original version. Hold the keys from the moment you power on, until the globe appears.

Will I lose my data?

Yes, if you format the drive: the operation erases everything, permanently. Back up what matters first. A simple reinstall over the existing system (without formatting) should in principle keep your data, but a backup is still essential.

Which format should I choose: APFS or Mac OS Extended?

APFS for macOS High Sierra (10.13) and later — that’s the recommended choice. Mac OS Extended (Journaled) only to install an older version. When in doubt, choose APFS. The scheme must be GUID Partition Map.

How long does it take?

Formatting is almost instant. The installation itself takes from 30 minutes to over an hour depending on your connection and your Mac, with several restarts. Keep the Mac plugged into the mains from start to finish.

Internet Recovery keeps failing — what should I do?

Check that the keys are held from the moment you power on, and try a different Wi-Fi network (corporate networks often block Recovery). An exclamation mark usually signals a network issue: move closer to the router and try again.

Place du Mac guide — reinstalling macOS via Internet Recovery is done in three moves (boot into Recovery, format the drive as APFS with the GUID scheme, reinstall macOS). The key combinations given apply to Intel-based Macs. Back up your data before any formatting. Apple, Mac, macOS, MacBook and Macintosh are trademarks of Apple Inc.; Place du Mac is an independent repairer, not affiliated with Apple Inc.