Your iPad can be a full second display for your Mac — no cables to buy, no monitor to ship, nothing to install. Apple calls it Sidecar, it has been built into macOS since Catalina, and it takes about thirty seconds to turn on. Here is exactly how to do it, which Macs and iPads support it, and how to fix it when the iPad refuses to show up.
What Sidecar actually does
Sidecar extends (or mirrors) your Mac desktop onto an iPad, wirelessly or over a USB cable. You can drag windows to it like any monitor, use an Apple Pencil on it as a drawing tablet, and get a Touch Bar strip along the bottom even on Macs that never had one. It is not screen sharing and it is not an app — the iPad behaves like a display the Mac drives directly.
One thing Sidecar is not: Universal Control. Universal Control lets one keyboard and mouse move between a Mac and an iPad running its own iPadOS apps. Sidecar turns the iPad into a monitor. Both ship with macOS; this guide is about the monitor one.
Check compatibility first (30 seconds)
Sidecar needs both devices signed into the same Apple ID with two-factor authentication on, and:
- Mac: macOS Catalina or newer on a MacBook Pro (2016+), MacBook Air (2018+), MacBook (2016+), Mac mini (2018+), iMac (2017+, or the late-2015 27-inch 5K), iMac Pro, Mac Studio, or Mac Pro (2019+). Every Apple-silicon Mac qualifies.
- iPad: iPadOS 13 or newer on any iPad Pro, iPad (6th gen+), iPad Air (3rd gen+), or iPad mini (5th gen+).
If your Mac predates that list, Sidecar simply will not appear — that is the number one "it doesn’t work" cause, not a setting.
How to turn it on
- Put the iPad near the Mac, awake and unlocked, Wi-Fi and Bluetooth on for both.
- On the Mac, open Control Center → Screen Mirroring (or System Settings → Displays → the + dropdown).
- Pick your iPad under "Extend or mirror to." The iPad becomes a display immediately.
- Arrange it like any monitor in System Settings → Displays — drag the blue rectangles so the layout matches your desk.
To end the session, click the Screen Mirroring icon again and disconnect, or tap the disconnect icon in the iPad sidebar.
Wired vs. wireless
Wireless Sidecar works within about 10 meters and is fine for documents, chat, and reference windows. Plug the iPad in with its USB cable and you get two upgrades: zero lag (video editing and drawing feel native) and the iPad charges while it works. If you notice cursor lag or dropped frames wirelessly, the cable fixes it every time.
The Pencil bonus
With Sidecar active, an Apple Pencil works on the iPad as a graphics tablet for Mac apps — Photoshop, Lightroom, Illustrator, Preview markup. A used iPad plus Pencil is dramatically cheaper than a dedicated pen display, which is why illustrators quietly love this feature.
When Sidecar will not connect: the fix list
- Same Apple ID on both? Different IDs (family iPad, work Mac) is the most common blocker after old hardware.
- Two-factor authentication on? Sidecar requires it. Check at System Settings → your name → Sign-In & Security.
- Handoff enabled? Mac: System Settings → General → AirDrop & Handoff. iPad: Settings → General → AirPlay & Handoff.
- Both on the same Wi-Fi network, with Bluetooth on. Hotspot mode on either device blocks it — turn Personal Hotspot off.
- Reboot both. Genuinely clears most remaining cases.
- Try the cable. If wired works but wireless never does, your Wi-Fi radio or network is the issue — the same radio problems that break AirPlay. Our MacBook AirPlay fix guide walks that chain.
- Firewall check: System Settings → Network → Firewall → Options — "Block all incoming connections" must be off.
Sidecar vs. a real monitor: the honest comparison
Sidecar is the best free second display, because you already own it. But an iPad screen is 11 to 13 inches; a $120 27-inch monitor is four times the glass and never drops a frame. Our rule: Sidecar for travel, couch work, and Pencil input; a real monitor for the desk you sit at daily. If you go the monitor route, start with the monitor guide, check your Mac’s wired display limit before buying two of anything, and see the dock guide if ports are tight. Note the wired limit is a separate system from Sidecar — Sidecar rides the AirPlay pipeline, so it works even on base M1 and M2 Macs that only drive one wired external display.
Building the whole setup on a budget
The cheapest dual-screen Mac setup we sell every week: a refurbished M1 MacBook Air (from $450) or M2 Air (from $549) plus the iPad already in your house — total new spend, the Mac only. Every machine in our Apple clearance section runs Sidecar out of the box, ships free, and carries a 1-year warranty. Still deciding between the two devices instead of pairing them? Read MacBook vs iPad first.
Frequently Asked Questions
Does Sidecar work with a USB cable instead of wirelessly?
Yes — plug the iPad into the Mac and select it the same way. Wired is lower-latency and charges the iPad; it is the right mode for drawing or video work.
Does Sidecar count against the M1/M2 one-external-monitor limit?
No. That limit applies to wired displays driven by the display controller. Sidecar streams over the AirPlay pipeline, so a base M1 Air can run one wired monitor and a Sidecar iPad at the same time.
Why doesn’t my iPad show up in Screen Mirroring?
Nine times out of ten: different Apple IDs, two-factor off, or a Mac/iPad too old for the compatibility list above. Work the fix list in order.
Can I use Sidecar with two iPads?
No — one Sidecar iPad at a time. Pair it with a wired monitor if you need three screens.
Is there lag when drawing with Apple Pencil over Sidecar?
Wireless has slight lag under heavy motion; over the cable it feels native. Artists should always run wired.
Does Sidecar work with an old Intel MacBook?
Yes, if it is on the compatibility list — MacBook Pro 2016 or newer, Air 2018 or newer — running Catalina+. Older Intel Macs can use third-party apps like Duet Display instead, but native Sidecar will not appear.