A method of producing a transparent polymer aerogel can include dissolving gel precursors consisting of radical polymerizable monomers and crosslinkers, radical initiators, and a chain transfer agent (CTA) in a reaction solvent, placing the gel precursors into a substrate, polymerizing the gel on the substrate, optionally removing the wet gel from the mold, optionally performing at least one solvent exchange on the gel, and drying the solvent-exchanged gel.