One name across iCloud, Google, and Exchange. Two photos that disagree. A phone number that's been wrong since 2014. ContactOne treats each as a question, not a guess.
iOS visually merges contacts linked across accounts, but the underlying records stay split. ContactOne reads them honestly - fuzzy-matching names, emails, phones, and birthdays - and groups what belongs together.
Every conflict is shown side-by-side with the source labeled. Pick the right photo, the right job title, the right number - and the destination account the merged record belongs in. Nothing is silently overwritten, and “Keep separate” permanently dismisses a pair that only looks like a match.
Matching, merging, undoing - all of it runs on your device using the system Contacts framework. There is no ContactOne server. There is no account to sign up for.
Changed your mind a week later? Open History, tap Undo. The original separate records come back, intact - and cleanups reverse the same way. Back up everything to a vCard first if you want a belt-and-braces snapshot. You're never one tap away from a regret.
Pick the look that matches your home screen - clay, indigo, forest, or mono - and the app icon changes with it. A small thing. Most people change it once and forget. We like that.
The Accounts tab shows what's actually living in iCloud, Google, and Exchange - separately, no auto‑merging. From there you can move any contact (or a batch) to the account where it should be. Useful when you're switching jobs, consolidating into one place, or quietly auditing a sync that's been off for years.
Once the duplicates are gone, the little inconsistencies remain - a number with no country code, a SHOUTING email, a stray “Work 2” label. Cleanups gets its own tab: review what ContactOne found, apply fixes in bulk, switch individual rules off, or write your own.
Dead Facebook URLs, defunct Skype handles, links that 404. ContactOne flags the ones that no longer resolve so you can drop them.
Add the country code and a leading “+” so every number is in full E.164 format - and dials correctly when you're travelling.
Optional, and off by default. Turn it on and mixed‑case addresses collapse to clean lowercase - you decide whether that's your style.
Merge the accidental duplicates iOS creates - “Work 2”, “iPhone”, “_$!<Home>!$_” - back into clean, standard labels.
All‑caps imports and lowercase typos become proper case - while preserving names that are meant to be unusual, like “McKenzie” or “van der Berg”.
Build a rule for the quirk that's yours alone - strip a legacy prefix, standardize a company name, retag an old account. It runs on every matching contact.
