comparekloq vs FullCalendarchecked 2026-09-01
FullCalendar is the safer choice for most teams. kloq is the better one if the calendar is the product.
FullCalendar is the most widely deployed calendar in the JavaScript ecosystem, and it has earned that. It is older, broader, battle-tested across four frameworks, and its React connector is first-class. If you need a calendar to exist inside your app, install it and move on. This page is about the narrower case where that is not enough.
- @fullcalendar/react
- v7.0.2
- npm, last week
- 1,639,091
- rows kloq wins
- 2
- rows kloq loses
- 3
01side by side
The table, with the losses left in.
Every number below was read from npm or from FullCalendar's own pricing page on 2026-09-01. Sources are at the foot of the page — check them.
| kloq | FullCalendar | verdict | |
|---|---|---|---|
| Core licenceBoth cores are genuinely open source. | MIT | MIT | even |
| What costs money | Only the source drop — every feature is free on npm | Premium plugins: timeline view, vertical resource view, print optimisation | even |
| Price for the paid tierFullCalendar Premium is a renewing subscription; lapsing keeps the last version you paid for. | $299 once, per team | From $480 per year, 1–10 developers | kloq |
| Drag to create, move, resizeNeither charges for the basic gestures. | Free | Free | even |
| Resource / timeline viewskloq schedules rooms, staff or machines on a horizontal timeline with the same drag primitives as the calendar: create, move a bar across rows to reassign its resource, resize, a context menu, zoom and a now indicator. FullCalendar's plugins are older and go further: theirs groups resources into a tree, and kloq has no grouping and is untested past a few hundred rows. Above that, or if you need a resource hierarchy, theirs is the one that works. | Built in, free | Premium plugins | even |
| Frameworks | React only | React, Vue, Angular, vanilla | them |
| React versions | 19 | 17, 18, 19 | them |
| Can you edit the internals? | Yes — the source tier lands the whole library in your repo | Premium includes source access; the MIT core is editable by forking | kloq |
| Styling | Tailwind v4 tokens, scoped to [data-kloq-root] | Its own CSS, themed with CSS variables | even |
| Maturity | 0.1.0, new, ~0 production installs | Ten-plus years, ~1.6M npm downloads a week | them |
02choose fullcalendar
When FullCalendar is the right answer.
Four cases where we would tell you to install theirs. If one of them is your case, stop reading — you have your answer and it isn't us.
You need resource grouping or hundreds of rows
Rooms down the side, time across the top: kloq does this now too. But FullCalendar's premium timeline view groups resources into a tree, and kloq has no grouping and no virtualization — past a few hundred rows, theirs is the one built for it.
You are not on React 19
FullCalendar's React connector supports 17, 18 and 19. kloq requires 19 and will not install below it.
You need the calendar in more than one framework
One FullCalendar API across React, Vue, Angular and vanilla. kloq is a React component and intends to stay one.
Boring is the requirement
A decade of production use, an enormous body of Stack Overflow answers, and a support contract you can buy. kloq is version 0.1.0 and cannot honestly claim any of that.
03choose kloq
And when we would say ours.
The narrower case — but it is the one this whole library was built for.
The calendar is the product, not a feature of it
When people will spend hours a day dragging things around, the gesture quality stops being a detail. kloq welds the grabbed point under the pointer, ramps edge auto-scroll, and springs a rejected change home — the drag engine writes transforms straight to the DOM and React sees nothing until you drop.
You want to own the code
The source tier is a one-time purchase that lands the whole library under components/kloq/ through the shadcn registry. Changing a spring is a line, not a fork and a maintenance burden.
You would rather not renew a licence forever
$299 once against $480 a year. Over three years that is the difference between one invoice and three, and nothing stops working if you never pay again.
You want a design surface, not just a widget
⌥D opens a calendar-aware inspector with live spring tuning, geometry overlays and a contrast-scoring theme picker. It exists because tuning motion by editing numbers and reloading is miserable.
04migration
What moving off FullCalendar looks like.
Not a codemod — an honest sketch of which concept becomes which. Most of the work is deleting things.
events={[{ title, start, end }]}defaultEvents={[{ id, title, start, end }]}Both take plain objects with real Date or ISO instants. kloq requires an id and discriminates timed vs all-day on an allDay flag.
eventDrop / eventResize callbacksonCommit(change)One seam for every committed change instead of a callback per gesture. Reject it and the block springs back on its own.
plugins={[dayGridPlugin, timeGridPlugin]}view="week" | "month" | 3No plugin registration. All six shapes — day, n-day, week, month, agenda, year — ship in the component behind one prop.
datesSetonRangeChangeSame job: tell the host which window is visible so it can fetch it.
05check us
Where these numbers came from.
Read on 2026-09-01. If something below has moved, the table is wrong and we would like to know.