<form>
The built-in browser <form> component lets you create interactive controls for submitting information.
<form action={search}>
<input name="query" />
<button type="submit">Search</button>
</form>- Reference
- Usage
- Handle form submission with an event handler
- Handle form submission with an action prop
- Preserve form values after submission
- Handle form submission with a Server Function
- Display a pending state during form submission
- Optimistically updating form data
- Handling form submission errors
- Display a form submission error without JavaScript
- Handling multiple submission types
Reference
<form>
To create interactive controls for submitting information, render the built-in browser <form> component.
<form action={search}>
<input name="query" />
<button type="submit">Search</button>
</form>Props
<form> supports all common element props.
action: a URL or function. When a URL is passed to action the form will behave like the HTML action. When a function is passed to action the function will handle the form submission in a Transition following the Action prop pattern. The function passed to action may be async and will be called with a single argument containing the form data of the submitted form. The action prop can be overridden by a formAction attribute on a <button>, <input type="submit">, or <input type="image"> component.
Caveats
- When a function is passed to
actionorformActionthe HTTP method will be POST regardless of value of themethodprop. - When a function is passed to
actionorformAction, React resets all uncontrolled field elements after the action succeeds. See Preserve form values after submission.
Usage
Handle form submission with an event handler
Pass a function to the onSubmit event handler to run code when the form is submitted. By default, the browser sends the form data to the current URL and refreshes the page, so call e.preventDefault() to override that behavior.
This example reads the submitted values with new FormData(e.target), which collects every field by its name. This keeps the inputs uncontrolled. If you instead control an input with state, read from that state on submit rather than from FormData.
export default function Search() { function handleSubmit(e) { // Prevent the default browser behavior // of reloading the page and resetting the form e.preventDefault(); // Read the form data const form = e.target; const formData = new FormData(form); const query = formData.get("query"); alert(`You searched for '${query}'`); } return ( <form onSubmit={handleSubmit}> <input name="query" /> <button type="submit">Search</button> </form> ); }
Handle form submission with an action prop
Pass a function to the action prop of form to run the function when the form is submitted. formData will be passed to the function as an argument so you can access the data submitted by the form. This differs from the conventional HTML action, which only accepts URLs. Unlike onSubmit, an action runs in a Transition and calling e.preventDefault() isn’t needed. After the action function succeeds, React resets all uncontrolled field elements in the form. To keep their values, see Preserve form values after submission.
export default function Search() { function search(formData) { const query = formData.get("query"); alert(`You searched for '${query}'`); } return ( <form action={search}> <input name="query" /> <button type="submit">Search</button> </form> ); }
Preserve form values after submission
The browser clears a form’s input state on submit. A URL action follows this same behavior. React does the same when action is a function, so your form works consistently before and after JavaScript loads.
When you pass a function to action or formAction, React resets the form’s uncontrolled fields after the action succeeds. The reset only applies to uncontrolled fields, so inputs you control with state are never cleared.
To keep the values of uncontrolled fields, add an onSubmit handler that calls e.preventDefault() and runs the action inside a Transition. Keep the action prop on the form so it still works before JavaScript loads.
import { useTransition } from "react"; import { submitForm } from "./api.js"; export default function EditForm() { const [isPending, startTransition] = useTransition(); function handleSubmit(e) { // Stop React from resetting the form after the action succeeds e.preventDefault(); const formData = new FormData(e.target); startTransition(async () => { await submitForm(formData); }); } return ( <form action={submitForm} onSubmit={handleSubmit}> <input name="title" defaultValue="My draft" /> <button type="submit" disabled={isPending}> {isPending ? "Saving..." : "Save"} </button> </form> ); }
Because you call the action manually from onSubmit, useFormStatus won’t report its pending state. Read isPending from the same useTransition call instead.
Deep Dive
The onSubmit approach keeps every uncontrolled field. When you need finer control, two other patterns are available:
-
Reset from your own action API. If you build an action-based API and still want the form to reset after the action runs, call the
requestFormResetAPI fromreact-domwith the form element inside the Transition. -
Reset to server-provided values. When an action validates input on the server, return the submitted
FormDataand pass it to each field’sdefaultValue. React restores those values instead of clearing them, and the form keeps working before JavaScript loads:
import { useActionState } from "react";
import { submitForm } from "./actions.js";
function EditForm() {
// The action returns { submitted: formData, error } on failure
const [state, formAction] = useActionState(submitForm, {});
const values = state.submitted ?? new FormData();
return (
<form action={formAction}>
<input name="title" defaultValue={values.get("title") ?? ""} />
{state.error && <p>{state.error}</p>}
<button type="submit">Save</button>
</form>
);
}Return the original FormData object rather than a new one so React can restore the values even before JavaScript has loaded.
Handle form submission with a Server Function
Render a <form> with an input and submit button. Pass a Server Function (a function marked with 'use server') to the action prop of form to run the function when the form is submitted.
Passing a Server Function to <form action> allow users to submit forms without JavaScript enabled or before the code has loaded. This is beneficial to users who have a slow connection, device, or have JavaScript disabled and is similar to the way forms work when a URL is passed to the action prop.
You can use hidden form fields to provide data to the <form>’s action. The Server Function will be called with the hidden form field data as an instance of FormData.
import { updateCart } from './lib.js';
function AddToCart({productId}) {
async function addToCart(formData) {
'use server'
const productId = formData.get('productId')
await updateCart(productId)
}
return (
<form action={addToCart}>
<input type="hidden" name="productId" value={productId} />
<button type="submit">Add to Cart</button>
</form>
);
}In lieu of using hidden form fields to provide data to the <form>’s action, you can call the bind method to supply it with extra arguments. This will bind a new argument (productId) to the function in addition to the formData that is passed as an argument to the function.
import { updateCart } from './lib.js';
function AddToCart({productId}) {
async function addToCart(productId, formData) {
"use server";
await updateCart(productId)
}
const addProductToCart = addToCart.bind(null, productId);
return (
<form action={addProductToCart}>
<button type="submit">Add to Cart</button>
</form>
);
}When <form> is rendered by a Server Component, and a Server Function is passed to the <form>’s action prop, the form is progressively enhanced.
Display a pending state during form submission
To display a pending state when a form is being submitted, you can call the useFormStatus Hook in a component rendered in a <form> and read the pending property returned.
Here, we use the pending property to indicate the form is submitting.
import { useFormStatus } from "react-dom"; import { submitForm } from "./actions.js"; function Submit() { const { pending } = useFormStatus(); return ( <button type="submit" disabled={pending}> {pending ? "Submitting..." : "Submit"} </button> ); } function Form({ action }) { return ( <form action={action}> <Submit /> </form> ); } export default function App() { return <Form action={submitForm} />; }
To learn more about the useFormStatus Hook see the reference documentation.
Optimistically updating form data
The useOptimistic Hook provides a way to optimistically update the user interface before a background operation, like a network request, completes. In the context of forms, this technique helps to make apps feel more responsive. When a user submits a form, instead of waiting for the server’s response to reflect the changes, the interface is immediately updated with the expected outcome.
For example, when a user types a message into the form and hits the “Send” button, the useOptimistic Hook allows the message to immediately appear in the list with a “Sending…” label, even before the message is actually sent to a server. This “optimistic” approach gives the impression of speed and responsiveness. The form then attempts to truly send the message in the background. Once the server confirms the message has been received, the “Sending…” label is removed.
import { useOptimistic, useState, useRef } from "react"; import { deliverMessage } from "./actions.js"; function Thread({ messages, sendMessage }) { const formRef = useRef(); async function formAction(formData) { addOptimisticMessage(formData.get("message")); formRef.current.reset(); await sendMessage(formData); } const [optimisticMessages, addOptimisticMessage] = useOptimistic( messages, (state, newMessage) => [ ...state, { text: newMessage, sending: true } ] ); return ( <> {optimisticMessages.map((message, index) => ( <div key={index}> {message.text} {!!message.sending && <small> (Sending...)</small>} </div> ))} <form action={formAction} ref={formRef}> <input type="text" name="message" placeholder="Hello!" /> <button type="submit">Send</button> </form> </> ); } export default function App() { const [messages, setMessages] = useState([ { text: "Hello there!", sending: false, key: 1 } ]); async function sendMessage(formData) { const sentMessage = await deliverMessage(formData.get("message")); setMessages((messages) => [...messages, { text: sentMessage }]); } return <Thread messages={messages} sendMessage={sendMessage} />; }
Handling form submission errors
In some cases the function called by a <form>’s action prop throws an error. You can handle these errors by wrapping <form> in an Error Boundary. If the function called by a <form>’s action prop throws an error, the fallback for the error boundary will be displayed.
import { ErrorBoundary } from "react-error-boundary"; export default function Search() { function search() { throw new Error("search error"); } return ( <ErrorBoundary fallback={<p>There was an error while submitting the form</p>} > <form action={search}> <input name="query" /> <button type="submit">Search</button> </form> </ErrorBoundary> ); }
Display a form submission error without JavaScript
Displaying a form submission error message before the JavaScript bundle loads for progressive enhancement requires that:
<form>be rendered by a Client Component- the function passed to the
<form>’sactionprop be a Server Function - the
useActionStateHook be used to display the error message
useActionState takes two parameters: a Server Function and an initial state. useActionState returns two values, a state variable and an action. The action returned by useActionState should be passed to the action prop of the form. The state variable returned by useActionState can be used to display an error message. The value returned by the Server Function passed to useActionState will be used to update the state variable.
import { useActionState } from "react"; import { signUpNewUser } from "./api"; export default function Page() { async function signup(prevState, formData) { "use server"; const email = formData.get("email"); try { await signUpNewUser(email); alert(`Added "${email}"`); } catch (err) { return err.toString(); } } const [message, signupAction] = useActionState(signup, null); return ( <> <h1>Signup for my newsletter</h1> <p>Signup with the same email twice to see an error</p> <form action={signupAction} id="signup-form"> <label htmlFor="email">Email: </label> <input name="email" id="email" placeholder="react@example.com" /> <button>Sign up</button> {!!message && <p>{message}</p>} </form> </> ); }
Learn more about updating state from a form action with the useActionState docs
Handling multiple submission types
A form can have more than one submit button, each running a different action. Set the formAction prop on a <button> to override the <form>’s action when that button submits the form.
When a button without formAction submits the form, React calls the form’s action. When a button with formAction submits the form, React calls that button’s action instead. For example, the form below publishes an article by default, but its Save draft button stores the current content without publishing it.
In this example the draft is held in state, so the saved content stays in the textarea after you submit it. In a real app you would persist the draft on the server. Pass a Server Function (a function marked with 'use server') to formAction to save the draft from the server, optionally combined with useActionState to track its pending state and result.
import { useState } from 'react'; export default function ArticleForm() { const [draft, setDraft] = useState(() => new FormData()); function publish(formData) { const content = formData.get('content'); alert(`'${content}' was published!`); // Clear the saved draft after publishing. setDraft(new FormData()); } function save(formData) { const content = formData.get('content'); alert(`Your draft of '${content}' was saved!`); // Keep the submitted content as the current draft. setDraft(formData); } const savedContent = draft.get('content') || ''; return ( <form action={publish}> <textarea // Changing the key resets the textarea to the saved draft. key={`${savedContent}-content`} name="content" rows={4} cols={40} defaultValue={savedContent} /> <br /> <button type="submit" name="button" value="submit">Publish</button> <button formAction={save}>Save draft</button> </form> ); }