Cookies, Firewalls, Browser support

Firewall and network settings

Codio can usually run from anywhere in your browser without any special settings. However, some k12 or university firewall settings may require special configuration.

This page contains information for

  • Network system administrators

  • Students and teachers who may be using Codio from home

Firewall settings

The following is a list of ports and URLs that Codio accesses from time to time. We have put these in priority order.

  • * the main Codio site and application

  • * domains that are auto-generated for each user project

  • statistics gathering to measure student time spent in units (stats)

  • * web fonts

  • web fonts

  • web fonts

  • * our CDN for speeding up static content

  • * & * for video’s included in Course content

  • used for user gravatars (pictures)

  • *, and * are highly recommended as they relate to the help and support application (Intercom) built into Codio.

If your institution blocks access to YouTube as a general rule, your IT department can whitelist YouTube access that only allows access to content from registered and accredited educational content repositories. See here for more information on this.


We recommend opening the following ports

  • 80 and 443 for standard communications

Working from home

Sometimes the anti-virus/firewall settings on your personal devices may interfere with home usage and make the experience slow.

You should check your settings and ensure that items in the above Firewall settings list are added to your exclusion list.

Connectivity Test

If you continue to experience difficulties, visit the Connection Diagnostics page and send us back the generated output going to Help > Support/Contact Us and attach the output file using the paperclip icon

Browser support

Codio is best experienced on the very latest browsers, in particular Chrome, but should run fine on the following browsers:

  • Chrome 21 or later

  • Firefox - 22 or later

  • Edge - 44 or later

  • Safari - 6 or later

If using Safari and accessing Codio via an LMS (Canvas/Blackboard/D2L/Moodle etc) , disable “Prevent cross-site tracking” to ensure access.

Safari Settings

If you are experiencing any issue where Codio will not run as it should, please send an email to

Disable IE Compatibility View

It could happen that even if you have Internet Explorer 10 or a later version, we detect an older version of the browser.

This is due to the Compatibility Mode of the Browser which enables old features we no longer support.

To disable this option, please go to *Tools → F12 developer tools* and be sure that in Browser Mode is selected «Internet Explorer 10» and in Document Mode is selected «Standards (Page default)».