HTMLResponse

HTMLResponse is a response class for returning HTML content. It sets the appropriate text/html content type header.

Import

from fastapi.responses import HTMLResponse

Class Signature

class HTMLResponse(Response):
    media_type = "text/html"

Constructor Parameters

str | bytes

default:"None"

The HTML content to return. Can be a string or bytes.

int

default:"200"

The HTTP status code for the response.

dict | None

default:"None"

Additional HTTP headers to include in the response.

str | None

default:"None"

Override the default media type. If not provided, uses text/html; charset=utf-8.

BackgroundTask | None

default:"None"

Background task to run after returning the response.

Usage

Using response_class

Specify HTMLResponse as the response class and return HTML as a string:

from fastapi import FastAPI
from fastapi.responses import HTMLResponse

app = FastAPI()

@app.get("/items/", response_class=HTMLResponse)
async def read_items():
    return """
    <html>
        <head>
            <title>Some HTML in here</title>
        </head>
        <body>
            <h1>Look ma! HTML!</h1>
        </body>
    </html>
    """

Direct HTMLResponse

Return an HTMLResponse object directly:

from fastapi import FastAPI
from fastapi.responses import HTMLResponse

app = FastAPI()

@app.get("/items/")
async def read_items():
    html_content = """
    <html>
        <head>
            <title>Some HTML in here</title>
        </head>
        <body>
            <h1>Look ma! HTML!</h1>
        </body>
    </html>
    """
    return HTMLResponse(content=html_content, status_code=200)

With Custom Headers

from fastapi import FastAPI
from fastapi.responses import HTMLResponse

app = FastAPI()

@app.get("/")
async def root():
    return HTMLResponse(
        content="<h1>Hello World</h1>",
        headers={"X-Custom-Header": "value"}
    )

Default Response Class

Set HTMLResponse as the default for all endpoints:

from fastapi import FastAPI
from fastapi.responses import HTMLResponse

app = FastAPI(default_response_class=HTMLResponse)

@app.get("/items/")
async def read_items():
    return "<h1>Items</h1><p>This is a list of items.</p>"

Properties

media_type

The media type for HTML responses:

HTMLResponse.media_type  # "text/html"

The actual Content-Type header will be text/html; charset=utf-8.

Notes

HTML content should be valid HTML markup
The charset is automatically set to UTF-8
Use this response class when building server-rendered pages or HTML fragments
For modern applications, consider using templating engines like Jinja2 with FastAPI

JSONResponse - For returning JSON data
PlainTextResponse - For plain text content
Templates - Using Jinja2 templates

Core

Parameters

Dependencies

Security

Responses

Middleware

Utilities

Import

Class Signature

Constructor Parameters

Usage

Using response_class

Direct HTMLResponse

With Custom Headers

Default Response Class

Properties

media_type

Notes

​Import

​Class Signature

​Constructor Parameters

​Usage

​Using response_class

​Direct HTMLResponse

​With Custom Headers

​Default Response Class

​Properties

​media_type

​Notes

​Related

Import

Class Signature

Constructor Parameters

Usage

Using response_class

Direct HTMLResponse

With Custom Headers

Default Response Class

Properties

media_type

Notes

Related