Office 2021 and Office 2024 are more alike than any comparison wants to admit: Word is Word in both, Excel opens the same spreadsheets, and nobody receiving your files can tell which version made them. What separates them now is the calendar. Office 2021 reached end of support on October 13, 2026, so it no longer receives security updates; Office 2024 is supported until October 9, 2029. That settles the question for anyone buying today. The rest of this guide covers what 2024 adds, what 2021 had that 2024 does not, and what to do if you are still running 2021.
Key takeaways
- Office 2021’s security updates ended on October 13, 2026. The apps keep working; the patches stopped.
- Office 2024 is supported until October 9, 2029 and is the version to buy new.
- Office 2024 adds Excel dynamic charts, the IMAGE function and fourteen text and array functions, Word session recovery, PowerPoint Cameo and Recording Studio, better Outlook search, and a Fluent-style look.
- Office 2021 Professional Plus included Publisher; no Office 2024 edition does.
- Neither version is a subscription, and neither includes Copilot or real-time co-authoring.
Contents
- What is identical
- Difference 1: support dates
- Difference 2: what 2024 adds
- Difference 3: what 2024 drops
- Side by side
- Which should you buy, or keep?
- Frequently asked questions
- Sources
What is identical
Both are one-time purchases with no subscription; if you are still weighing that model against Microsoft 365, our one-time purchase vs Microsoft 365 comparison covers the prices. Both install the full desktop apps, work offline, use the same file formats, and activate with a product key against Microsoft’s servers. Both followed Microsoft’s Fixed Lifecycle Policy of five years of support, with no extended phase. And both received no new features after release; what you bought is what you have.
Difference 1: support dates
| Office 2021 / Office LTSC 2021 | Office 2024 / Office LTSC 2024 | |
|---|---|---|
| Released | October 5, 2021 | September 18, 2024 (LTSC); October 1, 2024 (retail) |
| End of support | October 13, 2026 (passed) | October 9, 2029 |
| Extended support | None | None |
Since October 13, 2026, Microsoft has shipped no security fixes for Office 2021, Office LTSC 2021, Visio 2021 or Project 2021. Nothing was switched off that day: Word, Excel, Outlook and PowerPoint 2021 still open, edit and save files, your license did not expire, and your documents are untouched. What you lost is the safety net, and for software whose job is opening attachments and files from other people, that matters more with every month. Our article on Office 2021 end of support goes through what changed and the options.
Office 2024 gives you three more years of that safety net. That is the core of the recommendation, and it has nothing to do with features.
Difference 2: what 2024 adds
Modest but real, and all documented on Microsoft’s “What’s new in Office 2024” page:
- Excel: dynamic charts that follow a spilled array; the IMAGE function and pictures in cells; fourteen text and array functions (TEXTBEFORE, TEXTAFTER, TEXTSPLIT, VSTACK, HSTACK, TOROW, TOCOL, WRAPROWS, WRAPCOLS, TAKE, DROP, CHOOSEROWS, CHOOSECOLS, EXPAND); faster handling of several open workbooks. A workbook built with those functions shows #NAME? in Excel 2021.
- Word: session recovery after a crash; Like reactions and new-comment indicators; insert a photo from an Android phone (LTSC on Windows).
- PowerPoint: Cameo (your camera feed as a slide object) and Recording Studio (record and export a narrated video).
- Outlook: more relevant and faster search; automatic meeting shortening.
- OneNote (LTSC): improved inking.
- Access: Dataverse connector.
- Everywhere: a Fluent Design theme that matches Windows 11, ODF 1.4 support, improved accessibility tools.
Not in Office 2024, despite what some comparisons say: GROUPBY and PIVOTBY, Python in Excel, Copilot and live co-authoring are Microsoft 365 features. For the full list see what is new in Office 2024.
Difference 3: what 2024 drops
Office 2021 Professional Plus included Publisher. Microsoft did not include Publisher in Office LTSC 2024 or in the retail Office 2024 editions, and retired the product in October 2026, when support for the perpetual version ended alongside Office LTSC 2021. If you have .pub files, keep your Publisher 2021 installation to open them or export them to PDF before you move; Office 2024 will not open them.
Office 2024 also stops listing Windows 10 Home and Pro as supported platforms. Microsoft’s supported list for Office LTSC 2024 is Windows 11 (and Windows 11 LTSC 2024), Windows 10 LTSC 2019 and 2021, and Windows Server 2022 and 2025. Office 2024 will usually install and run on a Windows 10 PC, but Windows 10 itself reached end of support on October 14, 2025, so that combination is unsupported twice over.
Side by side
| Office 2021 | Office 2024 | |
|---|---|---|
| One-time purchase | Yes | Yes |
| Security updates today | No (ended October 13, 2026) | Yes, until October 9, 2029 |
| Word, Excel, PowerPoint, Outlook, OneNote | Yes | Yes |
| Access (Professional Plus) | Yes | Yes |
| Publisher (Professional Plus) | Yes | No, in any edition |
| Excel dynamic charts, IMAGE, TEXTSPLIT and the other new functions | No | Yes |
| PowerPoint Cameo and Recording Studio | No | Yes |
| Fluent theme matching Windows 11 | No | Yes |
| Microsoft-supported on Windows 11 | Yes | Yes |
| Microsoft-supported on Windows 10 Home/Pro | Was, until October 2025 | Not listed |
| Copilot, real-time co-authoring | No | No |
Which should you buy, or keep?
Buying Office today. Office 2024 Professional Plus, without much deliberation. The price difference between generations is small; three years of security updates versus none is not. If you do not need Access, Office 2024 Standard is the same suite without it; the edition comparison has the decision table.
Still running Office 2021. You are now unpatched. On a PC that reads email, opens files from outside, or holds client or financial data, move to 2024 now; the install guide takes about 20 minutes and your documents are not touched. On an offline or single-purpose machine that never receives outside files, continuing is defensible if you keep Windows patched and revisit the decision every few months.
You depend on Publisher. Keep Office 2021 Professional Plus installed for Publisher while you move the rest of your work, or export the Publisher files to PDF or Word and then upgrade. Do not expect a 2024 edition to add Publisher later; Microsoft has retired it.
Several PCs. The Office 2024 Professional Plus 5 PC pack is one key for up to five Windows PCs and is the usual route for a small office or household replacing several 2021 installs at once.
Frequently asked questions
Did Office 2021 stop working on October 13, 2026? No. It keeps opening, editing and saving files indefinitely. What ended is security patching, bug fixes and Microsoft support.
Can I upgrade from Office 2021 to 2024 without losing files? Yes. Documents are stored on your disk, not inside Office. Uninstall 2021, install 2024 with the Office Deployment Tool and your new key, and open the same files. Only Publisher files need exporting first.
Does Office 2024 run on Windows 10? It generally installs and runs, but Microsoft does not list Windows 10 Home or Pro as supported for Office LTSC 2024, and Windows 10 itself is out of support. Windows 11 is the supported combination; the Windows 11 Pro + Office 2024 bundle covers both.
Is Office 2024 a subscription? No. Like 2021, it is a perpetual license: one payment, supported until October 9, 2029, and still working after that.
Is there an upgrade price from 2021 to 2024? No. Microsoft’s perpetual licenses carry no upgrade rights; Office 2024 is a new license.
Sources
- Microsoft Learn, “Office LTSC 2021 lifecycle”: https://learn.microsoft.com/en-us/lifecycle/products/office-ltsc-2021
- Microsoft Learn, “Office LTSC 2024 lifecycle”: https://learn.microsoft.com/en-us/lifecycle/products/office-ltsc-2024
- Microsoft Learn, “Office 2024 lifecycle”: https://learn.microsoft.com/en-us/lifecycle/products/office-2024
- Microsoft Support, “What’s new in Office 2024 and Office LTSC 2024”: https://support.microsoft.com/topic/baadecbe-a8fc-4435-8cb8-70e93fd08b56
- Microsoft Learn, “Overview of Office LTSC 2024” (Publisher, supported operating systems): https://learn.microsoft.com/en-us/office/ltsc/2024/overview
- Microsoft Support, “Microsoft Publisher will no longer be supported after October 2026”: https://support.microsoft.com/en-us/office/microsoft-publisher-will-no-longer-be-supported-after-october-2026-ee6302a2-4bc7-4841-babf-8e9be3acbfd7
- Microsoft Learn, “Windows 10 Home and Pro lifecycle”: https://learn.microsoft.com/en-us/lifecycle/products/windows-10-home-and-pro
