ChessAtlas vs Spider Solitaire

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 Spider Solitaire
Detail	ChessAtlas	Spider Solitaire
What it does	Free chess opening trainer with spaced repetition	Free online card game with no download or account required
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	1, 2 and 4 suit difficulty levels Touch and mouse controls Keyboard shortcuts
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	No download or account required to play Works on any device with a modern web browser Game progress saved automatically in browser Unlimited undo to explore strategies risk-free Multiple difficulty levels for all skill levels
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)	17 +1 (up) since last check	15 +1 (up) since last check
Trust Flow (Majestic)	22	0
Citation Flow (Majestic)	24	10
Referring domains (Majestic)	34	3

4 details filled in for both companies.