Just search "differential" then look under "Forums":

https://easyeda.com/forum/topic/Differential-Signal-Layout-be74f31775ed4172b90a5f366590fd15

which includes a link to:

https://easyeda.com/forum/topic/Forecast-Tracks-length-Tuning-is-under-developing-d8b2266d6ecb430eaa5c27d6e1b17b54

See:

What’s new in v5.6.15

2018.07.21

New Features

• 
  Differential Pair Routing(First version)
  • Via: Topbar - Route - Differential Pair Routing...
  • Notice: The PCB differential pair net name must named as XXX_N, XXX_P or XXX+, XXX-

in:

https://easyeda.com/page/update-record

Thank you very much Andy !    I did not see the post from Eric.

By the way, it seems not to avoid obstacles:

Here it routed over the ground pad of a board edge SMA connector.

Many Thanks !
rudi

I made this particular project Public:
https://easyeda.com/luudee/usb-3-to-sma

I worked around the above issue, by:

1. moving the SMA connectors inside.
2. Then routing the differential signals.
3. locking the traces.
4. Moving the SMA connectors back.
5. Adding a small trace from the SMA connector to the differential signal.

It looks good now!~~~~

rudi

Thanks for your feedback.