Compress responses in your Flask app with gzip.

View the Project on GitHub libwilliam/flask-compress


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Flask-Compress allows you to easily compress your Flask application's responses with gzip.

The preferred solution is to have a server (like Nginx) automatically compress the static files for you. If you don't have that option Flask-Compress will solve the problem for you.

How it works

Flask-Compress both adds the various headers required for a compressed response and gzips the response data. This makes serving gzip compressed static files extremely easy.

Internally, every time a request is made the extension will check if it matches one of the compressible MIME types and will automatically attach the appropriate headers.


If you use pip then installation is simply:

$ pip install flask-compress

or, if you want the latest github version:

$ pip install git+git://github.com/libwilliam/flask-compress.git

You can also install Flask-Compress via Easy Install:

$ easy_install flask-compress

Using Flask-Compress

Flask-Compress is incredibly simple to use. In order to start gzip'ing your Flask application's assets, the first thing to do is let Flask-Compress know about your flask.Flask application object.

from flask import Flask
from flask_compress import Compress

app = Flask(__name__)

In many cases, however, one cannot expect a Flask instance to be ready at import time, and a common pattern is to return a Flask instance from within a function only after other configuration details have been taken care of. In these cases, Flask-Compress provides a simple function, flask_compress.Compress.init_app, which takes your application as an argument.

from flask import Flask
from flask_compress import Compress

compress = Compress()

def start_app():
    app = Flask(__name__)
    return app

In terms of automatically compressing your assets using gzip, passing your flask.Flask object to the flask_compress.Compress object is all that needs to be done.


Within your Flask application's settings you can provide the following settings to control the behavior of Flask-Compress. None of the settings are required.

Option Description Default
COMPRESS_MIMETYPES Set the list of mimetypes to compress here. [
COMPRESS_LEVEL Specifies the gzip compression level. 6
COMPRESS_MIN_SIZE Specifies the minimum file size threshold for compressing files. 500