why we need upload avatar file at confluence

[小川星児]

Bitbucket and JIRA is not need upload avatar file.
Becouse that is use Gravatar image file.
Why Confluence not use gravatar?

[Sam Hall]

I'm not sure why not supported, but there's a long-standing feature request to add Gravatar support to Confluence here, which you can vote on:

https://jira.atlassian.com/browse/CONF-19636

This one is also linked:

https://jira.atlassian.com/browse/CLOUD-6555

It's also worth being aware of the roll-out of Atlassian account to JIRA/Confluence Cloud. This results in one set of profile details used across all Cloud products and uses Gravatar by default when a user has not uploaded an avatar. There's a page about the roll-out status here.