FSRS on new websites
Free Spaced Repetition Scheduler, an open source algorithm library used by flashcard and learning apps to schedule reviews.
- Sites using FSRS
- 19
- since Jul 2026
- Last 30 days
- 0.0%
-
of new sites, to Oct 22
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 23, 2026 |
|---|---|
| Last seen | Oct 20, 2026 |
| Website | github.com |
What we found
- FSRS appeared on 8 new sites in the last 30 days.[1]
Share of new sites using FSRS
The line is the 7-day average share of new sites that use FSRS, since 10 September.
Who uses FSRS
| Ending | Sites | Share | Bar |
|---|---|---|---|
| .com | 8 | 42.1% | |
| .ai | 2 | 10.5% | |
| .org | 2 | 10.5% | |
| .app | 1 | 5.3% | |
| .dev | 1 | 5.3% | |
| .in | 1 | 5.3% | |
| .io | 1 | 5.3% | |
| .net | 1 | 5.3% | |
| .online | 1 | 5.3% | |
| .tech | 1 | 5.3% |
Javascript Library on new sites
| # | Movement | Tool | Share of category[2] | Bar | |
|---|---|---|---|---|---|
| 1 | – |
jQuery
|
34.4% | ||
| 2 | – |
React Router
|
16.2% | ||
| 3 | – |
Motion
|
14.4% | ||
| 4 | – |
TanStack Router
|
10.8% | ||
| 5 | – |
Swiper
|
8.2% | ||
| 6 | ▲1 |
ES Module Shims
|
7.0% | ||
| 7 | ▲1 |
js-cookie
|
6.0% | ||
| 8 | ▼2 |
Modernizr
|
5.9% | ||
| 9 | – |
GSAP
|
4.6% | ||
| 10 | ▼1 |
Lenis
|
3.3% | ||
| 11 | ▼1 |
Masonry
|
3.2% | ||
| 12 | – |
Three.js
|
3.1% | ||
| … | |||||
| 736 | ▼92 |
FSRS
|
<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 #861 in Javascript Library, down from #769 in August. All 1572 in Javascript Library
Recently launched products built on FSRS
12 of the 19 sites using FSRS are product launches we list individually. The other 7 are new business and personal sites: they count towards the figures above but are not listed here. A watch sends them to you.
China
Watches, exports and the API give you all 19 sites using FSRS, from £15 a month.
Notes
- These figures cover websites that went live since April 2026, not the web as a whole.
- 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 FSRS when we detect FSRS 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