Office 2024 vs Office 2021: which should you buy?

Office 2024 vs Office 2021 matters because Office 2021 reached end of support on 13 October 2026, while Office 2024 receives security updates until October 9, 2029. Both are one-time purchases with no subscription, but the newer version brings real improvements under the bonnet. Let’s walk through what’s actually different and whether you should upgrade or buy new.

The short version: if you’re buying fresh, get Office 2024. If you own Office 2021, you can stay put for now, but you’ll want to plan an upgrade before 2029 when support runs out.

• Support end dates and what happens after
• Actual feature differences (Excel, Word, PowerPoint)
• Whether Office 2024 is worth the cost
• System requirements for both versions
• Important truths about AI and Copilot
• How to switch from 2021 to 2024 without headaches

Support lifespans: the big story

Office 2021 ends on 13 October 2026, while Office 2024 is supported until 9 October 2029. That’s the deciding factor for most people. Once support ends, there will be no extension and no extended security updates, though your Office 2021 apps may continue to function; however, you could expose yourself to serious and potentially harmful security risks.

You’re already past the Office 2021 deadline if you’re reading this in November 2026. The apps still work, but they’re no longer receiving security patches. Not ideal for sensitive files or shared work.

Office 2024 buys you three more years of security updates, which matters if you’re managing company data or handling financial records. Microsoft will issue regular security patches to protect your system from vulnerabilities, as well as stability and quality updates to fix bugs; once support ends in 2029, the applications will continue to function, but they will no longer be patched, exposing you to potential security risks.

New features in Office 2024

Office 2024 isn’t a massive overhaul, but it adds new Excel functions, a refreshed design and PowerPoint recording tools while dropping Publisher.

Here’s what you actually get:

Excel improvements

Office 2024 includes new text and array functions, an IMAGE() function (which lets you insert images into cells more easily), and dynamic charts that auto-update based on array changes. Office 2021 had XLOOKUP, XMATCH, LET, and dynamic arrays (FILTER, SORT, UNIQUE, SEQUENCE), while Office 2024 adds all of 2021’s functions plus 14 text/array functions, IMAGE, dynamic charts, and faster multi-workbook processing.

If you work with big datasets or use Excel for serious analysis, these additions save time. If you mainly use it for invoices and budgets, you’ll notice little difference.

Word and performance

In Office 2024 there’s improved file-recovery (if your system crashes, Word can reopen the last session) and better support for the OpenDocument Format (ODF 1.4) meaning better inter-op with non-Microsoft formats.

The part that catches people out is that Office 2024 and Office 2021 look almost the same at first glance, with real differences in new Excel and PowerPoint features, the removal of Publisher, and, most importantly, how long Microsoft will keep sending security updates.

Collaboration tools

While Office 2021 supports OneDrive and basic co-authoring, Office 2024 steps up the real-time co-editing, smoother sync, and better remote-team features. Unlike Office 2021, Office 2024 includes tighter integration with Microsoft cloud services such as OneDrive and Teams, providing seamless file sharing and supporting real-time collaborative editing; additionally, Office 2024 offers enhanced commenting and annotation features.

The Copilot question

Don’t expect AI magic. Office 2024 does not have Copilot; the perpetual apps are a fixed 2024 build that receives security updates but no new features, while Copilot is a cloud service that Microsoft ties to an active subscription. If you want Copilot in Word or Excel, you need Microsoft 365, not a one-time Office 2024 licence.

File compatibility between versions

Files created in Office 2024 are fully compatible with Office 2021 and vice versa. You can send an Office 2024 file to someone with Office 2021 without worry. The catch is that some specific features of 2024 may not display correctly in 2021 – for example, a new Excel function won’t work if the recipient opens it in 2021.

When setting this up, test with a small file first if you’re sharing regularly with someone still on 2021.

System requirements and hardware

Both versions run on similar hardware. For Windows, you need Windows 11 or Windows 10, a 1.6 GHz dual-core processor, 4 GB of RAM, 4 GB of free disk space and a 1024 × 768 screen. Office 2024 requires Windows 10 minimum on Windows, whilst Office 2021 did the same, but macOS requirements differ: Office 2024 needs Ventura (13), while Office 2021 supported Big Sur (11).

If your machine is older than 2015, you might struggle. Windows 10 reached end of support on October 14, 2025, so for the longest-term security, Windows 11 is the recommended OS.

Cost and licensing

Prices vary by retailer and edition (Home, Home & Business, Professional Plus). Both are perpetual licences – you pay once and own it forever, with no monthly fees.

The decision usually comes down to this: if Office 2021’s support deadline (now passed) bothers you, or you need those Excel functions, spend the extra. If you bought Office 2021 recently and have no plans to upgrade for a year or two, hold off.

When you’re ready to buy Office 2024, Office 2024 Professional Plus from RealActivate is priced in GBP and includes the official Microsoft download link, so you’re getting a legitimate key with no hassle.

Can you upgrade from 2021 to 2024?

There’s no in-place upgrade path. You buy Office 2024 as a separate product and run the installer. Before you do, uninstall Office 2021 cleanly to avoid conflicts.

Note your Office bitness under File → Account → About Excel, and stick with the same bitness to keep add-ins working. If Office 2021 was 64-bit, install 2024 64-bit. Switching between 32-bit and 64-bit can break custom add-ins.

After uninstalling 2021, restart your computer before installing 2024. This prevents file locking issues and ensures a clean slate.

Frequently asked questions

Is Office 2024 worth buying if I already have Office 2021?

Not urgently, unless you use Excel heavily or work in teams that need better collaboration. If you’re past October 2026 and still on 2021, though, start planning your upgrade now.

Will my Office 2021 files open in Office 2024?

Yes, full compatibility both ways. New 2024 features may not show correctly in 2021, but the files open without error.

Does Office 2024 get new features after purchase?

Like Office 2021, it receives security and quality updates only; new features go to Microsoft 365. Both are locked to their launch feature set.

Can I install Office 2024 alongside Office 2021?

Not safely on the same machine. Uninstall 2021 first, restart, then install 2024. Running both causes registry conflicts and licensing headaches.

What happens to my Office 2021 licence after it reaches end of support?

The apps keep working indefinitely. Your licence doesn’t expire. What stops is Microsoft’s security patches and technical support. For home users with no sensitive data, it’s workable; for businesses, it’s risky.

Need an Office 2024 licence? Buy Office 2024 Professional Plus from RealActivate – priced in GBP and delivered by email with the official Microsoft download.