ChessAtlas vs Nepenthe Play

A side-by-side comparison built from both listings. Blank cells mean the company has not given that detail; we never guess.

ChessAtlas compared with Nepenthe Play
Detail	ChessAtlas	Nepenthe Play
What it does	Free chess opening trainer with spaced repetition	AI games, AI roleplay & text adventures
Stage	Not given	Growing
Founded	Not given	Not given
Based in	Not given	Not given
Pricing model	Freemium	Freemium
Pricing	Not given	Some experiences are free to play; paid usage spends Credits purchased through HowWorks.
Key features	Spaced repetition with FSRS algorithm Repertoire builder Opening trainer with instant feedback Game import from Lichess and Chess.com Deviation detection Course library with opening courses iOS and Android mobile apps Multiple language support	AI character interactions Phone-based texting with AI characters Interactive text adventures AI-powered casual games Multi-language support
What makes it different	FSRS algorithm schedules reviews 15-30% more efficiently than SM2 Automatic deviation detection from Lichess and Chess.com games Full repertoire builder in free tier with no course purchase required	Flexible AI that understands unanticipated questions and responds to different player approaches No download required, play directly in browser on desktop or mobile Building toward player creation tools
Free plan	Not given	Not given
Open source	Not given	Not given
Platforms	Not given	Not given
Public API	Not given	Not given
Community votes	0	0
DR (Domain Rating by Ahrefs)	10 +1 (up) since last check	1 +1 (up) since last check
Trust Flow (Majestic)	22	18
Citation Flow (Majestic)	24	19
Referring domains (Majestic)	34	5

4 details filled in for both companies.