Period Tools vs Clockbeam

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

Period Tools compared with Clockbeam
Detail	Period Tools	Clockbeam
What it does	Free, accurate cycle and period predictor	Free online digital clock with seconds, timer, stopwatch, and alarm
Stage	Startup	Not given
Founded	2026	Not given
Based in	Not given	Not given
Pricing model	Freemium	Free
Pricing	All calculators and guides are free. Period Tools Pro (optional): $4.99/month or $19.99/year.	All tools are free with no subscription or payment required.
Key features	Predicts next 6 periods Calculates ovulation day Identifies fertile window Private on-device tracking Cloud sync for Pro subscribers No signup required	Digital clock with seconds and date display Multiple display styles: minimal, flip, analog, scenic Fullscreen mode for classroom or second screen Countdown timer Stopwatch with lap support Online alarm with custom sounds World clock for multiple time zones Meeting time planner comparing working hours Pomodoro timer Customizable display options and themes
What makes it different	No data collection or server storage Uses standard medical calculation methods Honest about limitations and accuracy No aggressive marketing tactics	Completely free with no account required Works on all devices without installation No promise of alarm accuracy after closing browser Settings persist in browser with export option Accurate to device time with timezone customization
Community votes	0	0
DR (Domain Rating by Ahrefs)	15 no change since last check	23 no change since last check
Trust Flow (Majestic)	20	7
Citation Flow (Majestic)	9	25
Referring domains (Majestic)	77	75

5 details filled in for both companies.

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