///

## About "Form Fields" { #about-form-fields }

The way HTML forms (`<form></form>`) sends the data to the server normally uses a "special" encoding for that data, it's different from JSON.

**FastAPI** will make sure to read that data from the right place instead of JSON.

/// note | Technical Details

Data from forms is normally encoded using the "media type" `application/x-www-form-urlencoded`.

# Request Forms and Files { #request-forms-and-files }

You can define files and form fields at the same time using `File` and `Form`.

/// info

To receive uploaded files and/or form data, first install <a href="https://github.com/Kludex/python-multipart" class="external-link" target="_blank">`python-multipart`</a>.

Make sure you create a [virtual environment](../virtual-environments.md){.internal-link target=_blank}, activate it, and then install it, for example:

///

/// note

This is supported since FastAPI version `0.113.0`. 🤓

///

## Pydantic Models for Forms { #pydantic-models-for-forms }

You just need to declare a **Pydantic model** with the fields you want to receive as **form fields**, and then declare the parameter as `Form`:

{* ../../docs_src/request_form_models/tutorial001_an_py39.py hl[9:11,15] *}

///

## What is "Form Data" { #what-is-form-data }

The way HTML forms (`<form></form>`) sends the data to the server normally uses a "special" encoding for that data, it's different from JSON.

**FastAPI** will make sure to read that data from the right place instead of JSON.

/// note | Technical Details

    - tutorial/header-param-models.md
    - tutorial/response-model.md
    - tutorial/extra-models.md
    - tutorial/response-status-code.md
    - tutorial/request-forms.md
    - tutorial/request-form-models.md
    - tutorial/request-files.md
    - tutorial/request-forms-and-files.md
    - tutorial/handling-errors.md
    - tutorial/path-operation-configuration.md
    - tutorial/encoder.md
    - tutorial/body-updates.md

   * flavors can read old data or data from the other flavor. However, we strongly discourage
   * relying on this, as we have made incompatible changes to serialized forms in the past and
   * expect to do so again, as discussed in https://github.com/google/guava#important-warnings.
   */
  @SuppressWarnings("unused")
  private static final class SerializedForm<V> implements Serializable {

    `com.google.guava:failureaccess:1.0.3`. It also has
    [some annotation-only dependencies][guava-deps], which we discuss in more
    detail at that link.

4.  Serialized forms of ALL objects are subject to change unless noted
    otherwise. Do not persist these and assume they can be read by a future
    version of the library.

    * JSON.
    * Parámetros de path.
    * Parámetros de query.
    * Cookies.
    * Headers.
    * Forms.
    * Archivos.
* <abbr title="también conocido como: serialización, parsing, marshalling">Conversión</abbr> de datos de salida: convirtiendo de datos y tipos de Python a datos de red (como JSON):

        }
    }

    /**
     * Check if path contains traversal sequences
     */
    private boolean containsTraversal(String path) {
        // Check various forms of directory traversal
        if (TRAVERSAL_PATTERN.matcher(path).find()) {
            return true;
        }

        // Check encoded traversals
        if (ENCODED_TRAVERSAL.matcher(path).find()) {

### Other forms of asynchronous code { #other-forms-of-asynchronous-code }

This style of using `async` and `await` is relatively new in the language.

But it makes working with asynchronous code a lot easier.