Minify HTML output from Flask application with Jinja2 templates

Have a look here https://github.com/cobrateam/django-htmlmin#using-the-html_minify-function

I realise it is mainly used for django but the example shows how to use this projects code to do what you want with a flask view, i think.

I use the following decorators

import bs4
import functools
import htmlmin


def prettify(route_function):
    @functools.wraps(route_function)
    def wrapped(*args, **kwargs):
        yielded_html = route_function(*args, **kwargs)
        soup = bs4.BeautifulSoup(yielded_html, 'html.parser')
        return soup.prettify()

    return wrapped

def uglify(route_function):
    @functools.wraps(route_function)
    def wrapped(*args, **kwargs):
        yielded_html = route_function(*args, **kwargs)
        minified_html = htmlmin.minify(yielded_html)
        return minified_html

    return wrapped

And simply wrapped the default render_template function like so

if app.debug:
    flask.render_template = prettify(flask.render_template)
else:
    flask.render_template = uglify(flask.render_template)

This has the added benefit of being auto added to the cache, since we don't actually touch app.route

Found a better way to do this. You can minify all your pages with this method:

from flask import Flask
from htmlmin.main import minify

app = Flask(__name__)


@app.after_request
def response_minify(response):
    """
    minify html response to decrease site traffic
    """
    if response.content_type == u'text/html; charset=utf-8':
        response.set_data(
            minify(response.get_data(as_text=True))
        )

        return response
    return response