What is the maximum length of an FCM registration ID token? : <p>Working with the "new" Firebase Cloud Messaging, I would like to reliably save client device <code>registration_id</code> tokens to the local server database so that the server software can send them push notifications.</p>

<p><strong>What is the smallest size of database field that I should use to save 100% of client registration tokens generated?</strong></p>

<p>I have found two <a href="https://github.com/Chitrank-Dixit/django-fcm/blob/master/fcm/models.py#L26">different</a> <a href="https://github.com/xtrinch/fcm-django/blob/master/fcm_django/models.py#L74">libraries</a> that use <code>TextField</code> and <code>VarChar(255)</code> but nothing categorically defining the max length. In addition, I would like the server code to do a quick length check when receiving tokens to ensure they "look" right - what would be a good min length and set of characters to check for?</p>
