Flask-Squeeze is a Flask extension that automatically:

• Minifies repsonses with the mimetypes javascript and css
• Compresses all responses with brotli if the browser supports it, or gzip if the browser supports it!
• Protects against the BREACH exploit
• Caches static files so that they don't have to be re-compressed. The cache will be cleared each time Flask restarts. Files are considered static if the the substring "/static/" is in their request path.

Compatibility

• Tested with Python 3.7, 3.8, 3.9, 3.10, 3.11 and 3.12

Installation

pip install Flask-Squeeze

Usage

Initialize Flask-Squeeze BEFORE all other extensions and after_request handlers! Flask executes after_request handlers in reverse order of declaration, and the compression should be the last step before sending the response.

from flask_squeeze import Squeeze
squeeze = Squeeze()

def create_app():
    app = Flask(__name__)

    # Init Flask-Squeeze
    squeeze.init_app(app)

    # Init all other extensions
    # AFTER Flask-Squeeze

    return app

Thats it! The responses of your Flask app will now get minified and compressed, if the browser supports it. To control how Flask-Squeeze behaves, the following options exist:

General options

You can configure Flask-Squeeze with the following options in your Flask config:

Option	Default	Description
SQUEEZE_COMPRESS	True	Enables or disables compression
SQUEEZE_MIN_SIZE	500	Defines the minimum file size in bytes to activate the compression
SQUEEZE_VERBOSE_LOGGING	False	Enable or disable verbose logging. If enabled, Flask-Squeeze will print what it does into the terminal in a highlighted color
SQUEEZE_ADD_DEBUG_HEADERS	False	Add debug infos into the response headers, like call durations and cache hit infos. ONLY USE THIS IN DEVELOPMENT.

Minification options

Option	Default	Description
SQUEEZE_MINIFY_CSS	True	Enable or disable css minification using rcssmin
SQUEEZE_MINIFY_JS	True	Enable or disable js minification using rjsmin

Compression level options

Static files are chached, so they only have to be compressed once. Dynamic files like generated HTML files will not be cached, so they will be compressed for each response.

Option	Default	Description
SQUEEZE_LEVEL_BROTLI_STATIC	default=11, min=0 , max=11	Defines the compression level of brotli for static files
SQUEEZE_LEVEL_BROTLI_DYNAMIC	default=1, min=0, max=11	Defines the compression level of brotli for dynamic files
SQUEEZE_LEVEL_DEFLATE_STATIC	default=9, min=-1 , max=9	Defines the compression level of deflate for static files
SQUEEZE_LEVEL_DEFLATE_DYNAMIC	default=1, min=-1, max=9	Defines the compression level of deflate for dynamic files
SQUEEZE_LEVEL_GZIP_STATIC	default=9, min=0 , max=9	Defines the compression level of gzip for static files
SQUEEZE_LEVEL_GZIP_DYNAMIC	default=1, min=0, max=9	Defines the compression level of gzip for dynamic files