Brita filters do dechlorinate, however, it strips the water bare similar to reverse osmosis. These along with deionized water have been linked to kidney issues (bloat) in amphibians, reptiles and fish.

Personally, I use spring water for all of my reptiles and amphibians. (Kirkland Brand from CostCo)

There is an excellent article here on this topic. (Even though it is written with Caudates in mind, it is useful to keepers of Anurans too!)