isPending

import { isPending } from "solid-js"

function isPending(fn: () => any): boolean

isPending answers: "Does this expression currently have pending async work while also having a usable stale value?"

For a conceptual overview of the async model, see Async Reactivity.

Key behavior

• False during initial Loading fallback — there is no stale value yet, and the suspended subtree isn't producing UI.
• True during revalidation — once you've rendered at least once and the data is being refreshed in the background.
• Reactive — isPending() can be used directly in JSX or any reactive scope; it tracks dependencies and updates automatically.
• Works with actions — reflects pending state from transitions created by action().

This makes it ideal for showing subtle "refreshing…" indicators without replacing the whole subtree with a spinner.

Usage

import { createMemo, isPending, Show } from "solid-js"

const users = createMemo(() => fetchUsers())

function UserList() {
  return (
    <>
      <Show when={isPending(() => users())}>
        <div class="refreshing-banner">Refreshing...</div>
      </Show>
      <Loading fallback={<Spinner />}>
        <List users={users()} />
      </Loading>
    </>
  )
}

Combining multiple sources

You can check pending state across multiple async computations by reading them within the same expression:

const users = createMemo(() => fetchUsers())
const posts = createMemo(() => fetchPosts())

// Read both values to track pending state for either
const listPending = () => isPending(() => { users(); posts() })

Replaces .loading

In Solid 1.x, createResource had a .loading property. isPending replaces this with a more general mechanism that works for any expression:

// 1.x
data.loading

// 2.0
isPending(() => data())