 <p>Essentially this is a duplicate of <a href="http://stackoverflow.com/questions/2472422/django-file-upload-size-limit">Django File upload size limit</a> </p> <p>You have two options:</p> <ol> <li><p>Use validation in Django to check the uploaded file's size. The problem with this approach is that the file must be uploaded completely before it is validated. This means that if someone uploads a 1TB file, you'll probably run out of hard drive space before the user gets a form error.</p></li> <li><p>Configure the Web server to limit the allowed upload body size. e.g. if using Apache, set the <code>LimitRequestBody</code> setting. This will mean if a user tries to upload too much, they'll get an error page configurable in Apache</p></li> </ol> <p>As @pastylegs says in the comments, using a combination of both is probably the best approach. Say you want a maximum of 5MB, perhaps enforce a 20MB limit at the Web server level, and the 5MB limit at the Django level. The 20MB limit would provide some protection against malicious users, while the 5MB limit in Django provides good UX.</p>