ChessAtlas vs Playdeck24

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 Playdeck24
Detail	ChessAtlas	Playdeck24
What it does	Free chess opening trainer with spaced repetition	Free browser games playable in one tab, no downloads needed
Stage	Not given	Not given
Founded	Not given	Not given
Based in	Not given	Not given
Pricing model	Freemium	Free
Pricing	Not given	Not given
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	Daily leaderboards with verified scores Shared seeds for fair play Soft currency earned only through play Local progress storage Mobile and desktop playable No ads before first game 60 fps performance
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	Play directly in your browser with zero downloads or account setup required All players face identical daily challenges for fair competitive scoring
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	Not checked yet no change since last check
Trust Flow (Majestic)	22	19
Citation Flow (Majestic)	24	19
Referring domains (Majestic)	34	7

4 details filled in for both companies.