The Wales attack coach has been watching on closely as Biggar and Webb have led the Ospreys to two wins from two to open up their domestic campaign.
The second of those two wins was last weekend's narrow 17-15 success over Newport Gwent Dragons, where Webb scored one try and set up another, while Biggar pulled the strings at No.10.
And with the Welsh region hosting Edinburgh on Sunday, Howley is excited to see the duo continue their fine partnership.
"Having watched Rhys closely over the last couple of weeks, his partnership with Dan was the deciding factor in the win over the Dragons," Howley told Wales Online.
"They brought a bit of X factor. Rhys took his try well and created the other with his chip for Eli Walker.
"Rhys played well for Wales before coming off against England, while Dan has matured and gets better with every game he plays.
"It's good to have competition moving forward over the next 12 months.
"There are a lot of good scrum-halves in Wales.
"You look at the three nines down at Parc y Scarlets in Rhodri Williams, Aled Davies and Gareth Davies."
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