2.2.1 [WEBSTG] Section 5, Disk space


The specification states:

 A mostly arbitrary limit of five megabytes per origin is recommended.

IE8 Mode, IE9 Mode, IE10 Mode, IE11 Mode, and EdgeHTML Mode (All Versions)

Storage for approximately five million characters is supported, including key name and value strings.


The specification states:

 User agents should guard against sites storing data under the origins other affiliated sites, e.g. storing up to the limit in a1.example.com, a2.example.com, a3.example.com, etc, circumventing the main example.com storage limit.

IE8 Mode and IE9 Mode (All Versions)

Total storage is limited to 100MB.

IE10 Mode (All Versions)

There is no protection for this situation.

IE11 Mode and EdgeHTML Mode (All Versions)

There is a total storage limit of 100MB, and a limit of 20MB per top level domain name.