HARDER vs ContactZapp

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

HARDER compared with ContactZapp
Detail	HARDER	ContactZapp
What it does	Challenges with photo proof, pre-written steps and a built-in comeback	Sync your contacts between Google, Microsoft, Apple and CardDAV. Find and merge duplicates easily.
Stage	Startup	Not given
Founded	2026	Not given
Based in	PL	Not given
Pricing model	Freemium	Freemium
Pricing	Free plan includes 5 personal challenges per month, 5 private challenges per month, 1 public challenge per month, 1 public with approval challenge per month, and 1 extra space. Premium plan costs $7.99 per month (or annual pricing available) and includes unlimited personal, private, and public chall	Free plan: 2 synced accounts, 100 contacts, no time limit. Easy plan: $4.00/month (billed $47.94/year, was $95.88). Unlimited plan: $8.00/month (billed $95.94/year, was $191.88). 50% off Easy and Unlimited with code HALLOWEEN.
Key features	Pre-written daily steps for every challenge Photo, text, or Apple Health proof verification Automatic comeback system after missed days 200+ ready-made challenges across multiple categories Personal, private, or public challenge visibility Offline functionality with sync Space profiles and social community	Two-way sync across Google, Microsoft, Apple and CardDAV Merge duplicates in one go, or review them one by one Full change history with undo capability Backups and vCard export Sync frequency control (hourly, daily, or manual) Set accounts to read-only mode Preserve all phone numbers and email addresses Up to 5 encrypted account backups 12-month undo history Restore deleted contacts for 12 months
What makes it different	Pre-written daily steps eliminate decision fatigue and executive function burden Missing a day doesn't reset progress—you pick up where you stopped Proof-based accountability that creates genuine evidence, not just checkboxes Automatic health data verification eliminates manual proof entry Join anytime without waiting for a challenge start date	Syncs across all major platforms in both directions automatically Encrypted contacts with privacy key per account Undo any change for up to 12 months No time limit on free plan Automatic duplicate detection and optional auto-merge
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)	4 no change since last check	Not checked yet no change since last check
Trust Flow (Majestic)	0	0
Citation Flow (Majestic)	0	11
Referring domains (Majestic)	0	1

5 details filled in for both companies.

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