Apple iMac 21.5" (2019) All-in-One Desktop Intel Core i5 – 16GB RAM, 256GB SSD Retina 4K Display macOS

Apple iMac 21.5" (2019) MRT42LL/A delivers sharp 4K clarity for creative everyday work

This 2019 Apple iMac 21.5" with Retina 4K display (model MRT42LL/A) blends a sharp 4096x2304 screen, a 3.0GHz 6-core Intel Core i5 processor, and 16GB RAM into a sleek all-in-one aluminum design. As a professionally refurbished unit, it’s tuned for smooth productivity, light-to-moderate creative workloads, and everyday computing without cluttering your desk.

Fast Facts

Why it stands out

The Apple iMac 21.5" (2019) MRT42LL/A stands out by solving a common pain point: needing a color-rich, sharp display and reliable performance without a bulky tower. The Retina 4K panel makes photos, timelines, and documents look crisp, while the 6-core Intel Core i5 and 16GB RAM keep multitasking responsive. Its all-in-one aluminum design reduces cable clutter so your workspace feels clean and focused.

Key features

• Retina 4K display → Vivid detail → Text, photos, and video timelines look sharp, reducing eye strain during long sessions.
• 6-core Intel Core i5 → Smooth multitasking → Run browsers, office apps, and creative tools together without constant slowdowns.
• 16GB RAM → Room for heavier workflows → Keep multiple apps and large files open so you spend less time waiting and more time creating.
• 256GB SSD → Fast boot and load times → The system wakes quickly and apps launch in seconds, keeping your day moving.
• All-in-one aluminum design → Minimal desk clutter → A clean, modern setup that fits easily on a standard home or office desk.

Performance snapshot

Responsive everyday performance: 6-core Intel Core i5-8500 keeps office apps and browsing smooth.

Comfortable multitasking: 16GB RAM supports multiple apps and browser tabs without frequent slowdowns.

Quick startup and loading: 256GB SSD helps the iMac boot fast and open files and apps in seconds.

Technical specifications

The honest fit: who it’s for and not for

For: This Apple iMac 21.5" (2019) MRT42LL/A is ideal for students, home users, and professionals who need a sharp 4K display for documents, web work, light photo editing, and everyday creative tasks. It suits users who value a clean, all-in-one setup and want reliable performance without managing a separate tower and monitor.

NOT For: This iMac is not the best fit for heavy 4K video editing, advanced 3D rendering, or modern AAA gaming. If you require top-tier GPU performance for large-scale visual effects, complex 3D scenes, or high-frame-rate 4K gaming, a workstation-class system with a more powerful dedicated graphics card would be a better choice.

Decision snapshot

FAQ

Is this Apple iMac 21.5" (2019) MRT42LL/A fully tested?

Yes, this refurbished iMac has been tested to ensure the display, ports, storage, and internal components are fully functional.

Does this iMac come with a warranty?

Yes, this refurbished unit includes a limited warranty period from the seller; details may vary by retailer, so check the listing for exact coverage.

Can I upgrade the RAM later?

No, on this 21.5-inch 2019 iMac, RAM is not designed for easy user upgrades, so you should plan to use the included 16GB RAM.

Can I connect external displays?

Yes, you can connect compatible external displays using the Thunderbolt 3 (USB‑C) ports, subject to adapter and monitor support.

Does it include an Apple keyboard and mouse?

No, this refurbished iMac includes a generic wired keyboard and mouse instead of original Apple-branded peripherals.

What’s included

• Apple iMac 21.5" (2019) MRT42LL/A all-in-one desktop (Silver)
• Power cable
• Generic wired keyboard
• Generic wired mouse

Smart investment

Choosing this refurbished Apple iMac 21.5" (2019) MRT42LL/A gives you a premium Retina 4K display, solid 6-core Intel Core i5 performance, and 16GB RAM at a more accessible price than buying new. The all-in-one design reduces clutter and is built from durable aluminum, so it feels at home in both modern offices and home workspaces. For users who want Apple’s design and display quality without paying full retail, it’s a practical, long-term upgrade.

Quick reference

• Brand: Apple
• Model: iMac 21.5" (2019) MRT42LL/A
• CPU: Intel Core i5-8500, 3.0GHz (up to 4.1GHz), 6-core
• RAM: 16GB DDR4 RAM
• Storage: 256GB SSD
• Display: 21.5-inch Retina 4K, 4096x2304
• Operating System: macOS (version may vary)
• Condition: Refurbished
• Warranty: Limited seller warranty (see listing for details)