Office.js on new websites
JavaScript API library that lets web based Office Add-ins interact with Word, Excel, Outlook and PowerPoint.
- Sites using Office.js
- 49
- since Jul 2026
- Last 30 days
- 0.0%
-
of new sites, to Oct 19
no change on the 30 days before - Last 7 days
- 0.0%
- of new sites, 7-day average
no change on the week before
| First seen | Jul 11, 2026 |
|---|---|
| Last seen | Oct 9, 2026 |
What we found
- Office.js appeared on 11 new sites in the last 30 days.[1]
- Seven in ten new Office.js sites also use Microsoft 365.
Share of new sites using Office.js
The line is the 7-day average share of new sites that use Office.js, since 10 September.
Who uses Office.js
| Type | Sites | Share | Bar |
|---|---|---|---|
| Productivity | 17 | 58.6% | |
| Finance | 7 | 24.1% | |
| Developer Tools | 2 | 6.9% | |
| AI | 1 | 3.5% | |
| Crypto | 1 | 3.5% | |
| Marketing | 1 | 3.5% |
| Country | Sites | Share | Bar |
|---|---|---|---|
 US |
7 | 53.9% | |
 India |
2 | 15.4% | |
 Canada |
1 | 7.7% | |
 Ireland |
1 | 7.7% | |
 Italy |
1 | 7.7% | |
 Luxembourg |
1 | 7.7% |
| Ending | Sites | Share | Bar |
|---|---|---|---|
| .com | 20 | 40.8% | |
| .ai | 7 | 14.3% | |
| .us | 5 | 10.2% | |
| .app | 3 | 6.1% | |
| .co | 2 | 4.1% | |
| .dev | 2 | 4.1% |
Javascript Library on new sites
| # | Movement | Tool | Share of category[3] | Bar | |
|---|---|---|---|---|---|
| 1 | – |
jQuery
|
34.4% | ||
| 2 | – |
React Router
|
16.2% | ||
| 3 | – |
Motion
|
14.5% | ||
| 4 | – |
TanStack Router
|
10.7% | ||
| 5 | – |
Swiper
|
8.2% | ||
| … | |||||
| 491 | ▲34 | Office.js | <0.1% | ||
All-time shares across the new sites we track: of all of them, and of the sites using any Javascript Library tool. Among September launches it ranked #456 in Javascript Library, up from #490 in August. All 1553 in Javascript Library
Often used with Office.js
| Tool | Sites with both | vs all new sites |
|---|---|---|
Microsoft 365
|
36 | 37x |
Tools that turn up far more often on Office.js sites than on new sites in general, and how many times as common each one is there.
Recently launched products built on Office.js
28 of the 49 sites using Office.js are product launches we list individually. The other 21 are new business and personal sites: they count towards the figures above but are not listed here. A watch sends them to you.
Showing the most recent 12 of 28.
Watches, exports and the API give you all 49 sites using Office.js, from £15 a month.
Notes
- These figures cover websites that went live since April 2026, not the web as a whole.
- Country comes from what each site says about itself, such as a company registration, legal terms or a phone number, not just its domain ending. Too few sites state their country plainly for the usual count, so this one also counts single signals: a country domain ending, a phone number (for North America, its area code), a location the site declares in its own page metadata, or a country-specific vendor stack and the page language where they agree and nothing contradicts them. Read these as likely rather than certain.
- Some products people expect to see here are filed under a related category: UI Library.
How this page is made
FirstSited looks at each new website near the day it goes live and records what it was built with. We do not go back later, so these figures describe what sites launch with, not what they run today. A site counts towards Office.js when we detect Office.js on it at that look.
Every share on this page is a proportion of the new sites we were tracking at the time. Sites we found across the wider web count towards the figures, but only product launches are listed by name. How we detect technologies · How we find new sites