# Contacts Optimizer Pro — user reviews > 92 indexed App Store user reviews of Contacts Optimizer Pro by Compelson s.r.o., rated 3.30/5 from 70 ratings. - Source: https://appshunter.io/ios/app/contacts-optimizer-pro/id908963063/reviews - App overview in markdown: https://appshunter.io/ios/app/contacts-optimizer-pro/id908963063.md - Rating breakdown: 5★ 30 · 4★ 10 · 3★ 3 · 2★ 5 · 1★ 22 ## What do users think of Contacts Optimizer Pro? Overall sentiment: mixed **Pros** - 🚀 Fast and efficient batch processing of contacts - 👍 User-friendly interface and easy to use - ✨ Effective duplicate detection and removal - 🌍 Excellent international phone number formatting - 💰 Affordable one-time purchase price - 🔧 Multiple contact management tools in one app - ✅ Works well with iCloud contacts - 📱 Handles large contact lists (1000+ contacts) - 🎯 Accurate contact merging with preview functionality - 💬 Responsive developer support (historical) **Cons** - 🐛 Frequent crashes and compatibility issues - ❌ Does not work with Exchange Server accounts - 🔌 Poor syncing across devices and cloud accounts - ⚠️ Dangerous data loss and unintended deletions - 🚫 Fails to recognize contacts on some devices - 🌐 Non-English character handling is broken - 📞 Incorrect phone number field modifications - 🔍 Inaccurate duplicate/similar contact detection - 📧 Inadequate customer support and communication - ⏱️ App crashes during analysis of large contact lists - 🔄 Sync failures between accounts and devices - ❌ Does not work reliably on iOS 14+ - 🎨 Poor color contrast for colorblind users **Commonly reported bugs** - App cannot read contact list on some devices - Crashes after analyzing 12% of large contact lists - Non-English characters marked as invalid and removed - Incorrect letter-to-digit conversion in number fields - Failure to communicate with contacts service error - App crashes during Edit Contacts function - Sync does not carry over to other devices - Creates new duplicate entries after cleanup - Does not work with Exchange Server - Incompatibility with iOS 14 and later versions - Cannot find duplicates in large contact databases - Similar contacts detection shows unrelated contacts - Missing activation key after App Store purchase - No account information or profile page accessible **Most requested features** - Selective field modification (phone numbers only, names only, etc.) - Regex support for search and replace - Default field customization for all contacts - Area code addition to local phone numbers - Ability to select specific phone numbers within a contact to modify - Better handling of business contacts without first/last names - More granular merge options with additional matching criteria - Dark mode option - Clearer app description of capabilities ## Newest reviews (12 of 92) ### 2/5 — Disappointed - not with it *2025-05-13* I was disappointed. Hit this based on a review to merge/delete duplicate contacts, and app promises to do a lot more. But 1. It sees all non-English characters in a contact as invalid. If you have contacts with (say) Hebrew names, app wants to remove them 2. It tried to change any letter in a number field into its equivalent digit. So if I have a contact they say ‘ext: 1234’ app wants to change it into ‘398: 1234’ 3. It has a functions to handle ‘similar’ contacts, but shows totally different contacts as similar ### 3/5 — A great but flawed app *2023-02-07* Contact management is extremely important for all people. And smartphones are dumb at managing contacts. This app helps, however, it seems to have some significant difficulties syncing completely and correctly. After sorting out thousands of contacts, i download the app on another phone with all the same gmail and i cloud and outlook accounts logged into, but the sync has not been able to carry over to the accounts and other devices. This is actually dangerous as it can potentially erase all your hard work, and even create new duplicate contact entries, creating more headache and confusion. Fix the sync to accounts issue and its 5 stars. ### 4/5 — Can’t add field to all contacts by default, but does everything else *2023-01-17, version 4.3.2* I was hoping to change the default fields displayed in contacts (add a new field such as prefix to all my contacts). Sadly this app can’t help but it looks like an excellent contacts management tool. ### 3/5 — Unsure what this is for. *2022-01-18, version 4.3.1* Tried to use this to combine various accounts on any new iPhone. Didn’t work and unsure what this app actually achieves? A lot of money. Maybe description needs to be clearer? ### 1/5 — Needs update *2020-12-13, version 4.2.1* Told since October would be update still nothing..... ### 4/5 — Nothing found *2020-12-05, version 4.2.1* I have an iCloud database of 15000 contacts. This app couldn’t find a single duplicate or similar contact, nor could it find anything else to improve or fix on any of its toolbox runs. Now I know my contacts list is a mess... amd there’s no way this app could have even checked at 15000 contacts in the 1/2 second before it said it found nothing. I couldn’t get ANY function of this app to work. ### 1/5 — Why sell it if it doesn’t work on iOS 14 *2020-11-03, version 4.2.1* Didn’t work . Looking at the reviews it’s not optimised fit iOS 14 ### 1/5 — Dreadful. Makes no changes. *2020-10-24, version 4.2.1* This app is not fit for purpose. ### 2/5 — Good at optimizing but it keeps deleting and duplicating my contacts *2020-09-29* I loved this app at first but now it keeps deleting my contact cards. I don’t know what the heck is happening but it deletes them from the cloud or my phone and then next thing I know I’ve got massive duplicates again. **Developer response:** iOS 14 finally supported! Apple has started to require a new approval process for apps with the editing notes capability in contacts, which we need to reliably evaluate duplicates. We finally got through. Sorry for letting you wait. We are working on new features. If you like the Contacts Optimizer, please rate it. ### 4/5 — This is the app I needed *2020-03-21, version 4.2.1* I have multiple accounts with hundreds of contacts and many in multiple accounts. Contacts Optimizer sorted them very easily. ### 3/5 — Struggling with mass contacts *2020-01-02, version 4.2.1* It is a great app and I have used it successfully on my Android device with no issues. However, since I have started using the iOS version a few days ago trying to merge contacts, it keeps on crashing after analysing about 12%. Each time it reads 100% of the contacts, about 4,000, and as soon as it is analysing contacts to merge it crashes. ### 3/5 — Disappointed *2019-03-25, version 4.2.1* App works as described but in my own case made very few changes. It was not worth paying for it, but some people may find it useful. ## Most critical reviews (10 lowest-rated) ### 1/5 — No Support *2024-03-08* Everything I tried to do to ask a support question results in a form, where I am asked if I purchased a license, and I checked the box to indicate yes. The form then asks for an activation key I have looked at all my emails and received, no application key email today, when I purchased the product through the Apple App Store. I have looked all over the application, and can find no activation key, or any sort of profile page with account information about my account. This is the only way I seem to be able to send a message. I hate to do it this way, but I need support. I need communications. Thank you. Rick. ### 1/5 — Warning! Does not work with Exchange Aerver *2022-06-21* I copied contacts from one Exchange account to another. On the iPhone, it appears to have worked. But. The changes did not sync back for the target account. In Outlook client on a Mac, contacts were lost. When logging into the Exchange Server directly with OWA, contacts were lost. DOES NOT WORK WITH EXCHANGE SERVER. The only cloud account that works is iCloud. DESERVES NEGATIVE 10 RATING ### 1/5 — Not what I wanted *2022-02-08* I thought this app would add area codes to my local seven digit phone numbers but I can’t figure out if it will or how to do it. Zero stars ### 1/5 — Not working *2021-02-16* It can’t even read my contact list let alone do the other things it claims to do. Mist be a compatibility issue and if that’s the case an update is required ASAP! I’m on iOS 14.5. **Developer response:** iOS 14 finally supported! Apple has started to require a new approval process for apps with the editing notes capability in contacts, which we need to reliably evaluate duplicates. We finally got through. Sorry for letting you wait. We are working on new features. If you like the Contacts Optimizer, please rate it. ### 1/5 — TRASH NOW!!!! *2021-02-13* No wonder they gave the “Pro” version!!! I have multiple DUPLICATES in my Contacts-List. Yet, this App says: “No contacts found for this list!!! Garbage!!!! Don’t waste your space getting this!!! **Developer response:** iOS 14 finally supported! Apple has started to require a new approval process for apps with the editing notes capability in contacts, which we need to reliably evaluate duplicates. We finally got through. Sorry for letting you wait. We are working on new features. If you like the Contacts Optimizer, please rate it. ### 1/5 — WORST APP EVER WORST DEVELOPER MOST CARELESS DEVELOPER *2021-02-01, version 4.2.1* ZERO STAR FOR THIS APP DEVELOPER DOESNT FIX APP AFTER 1 YEAR THAT APP DOESNT WORK AT ALL ### 1/5 — 9999 *2021-01-16, version 4.2.1* Does not recognize contacts on the iphone. Emailed them. They said sorry that does not work yet??? That’s all it does ### 1/5 — Safe of money!! *2021-01-09, version 4.2.1* I downloaded the app a few months over 6 months ago. And I have been repeatedly trying to contact the developer to inquire about updates as it does not work with iCloud. Don’t waste your money! ### 1/5 — New iPhone? Skip this purchase *2021-01-08, version 4.2.1* A waist of 2 buck. It basically does nothing on a new phone with the latest iOS. ### 1/5 — Doesn’t work with iOS14 *2020-12-20, version 4.2.1* Please fix this. It literally doesn’t work. ## Most praised reviews (10 highest-rated) ### 5/5 — App works very well in IOS 14+ *2025-01-29* I saw some feedbacks saying it didn’t work, but it works for me very well. Great app for the price! ### 5/5 — App works very well in IOS 14+ *2021-07-15, version 4.3.1* I saw some feedbacks saying it didn’t work, but it works for me very well. Great app for the price! ### 5/5 — Very quick *2020-07-24* Seems good. Easy instructions, fast operation ### 5/5 — The perfect solution for contact management! *2020-05-01* This app was exactly what I needed. I had been looking on my Mac for a tool to get all my contacts synced. I thought it would be easy but definitely not. Little did I realize the perfect tool was right on my phone. I was able to sync my Office 365 contacts with my iCloud on about 10 seconds. Then everything uploaded to iCloud and now everything is synced with my Mac. Easy peasy. So many other tools too for managing duplicates. Everything worked so well, I was pretty astounded. Can’t remember how much I paid but if whatever it was it was well worth it. I wish I had gone to the app in the first place, I’d could have saved myself about 2 hours of fumbling around. ### 5/5 — Great app! *2020-02-28, version 4.2.1* This is an Awesome app! Must have, I was able to modify my huge list of contacts and add the country code as I moved countries with ease. 1 Advice: the search and replace tool is very useful, but I miss the ability of selecting that I want to change only the phone numbers, or the names, etc. or even the possibility of using regexes would make it way more powerful ### 5/5 — INCREDIBLE!!!! *2019-09-10* This is by far the absolute best app to delete duplicate contacts. No other app I have found can intelligently judge two or more contacts with the same name but different numbers and make a decision to keep them. It’s easy, fast and accurate! A bonus is the fact that it’s real cheap and it has advanced searching functions which are just out of this world! **Developer response:** Thank you for your comment! We’ve spent a few years fine-tuning the app and are working on a new great version. ### 5/5 — Country change *2019-08-18, version 4.2.1* If you change your country just like me and all of your contacts messed up because of country codes, this app is the best for you!! My first payment in app store and I didnt regret a penny!! Absolutely saved my contacts. Thank you! ### 5/5 — iPhone Optimizer *2019-01-11* I cannot believe how simple this app does all the work that I thought I would have to do manually, one by one! Absolutely EXCELLENT! I am amazed at how fast and efficient this app really is! My dear husband (a systems engineer) found this fabulous tool to help me clean up my contacts!! I am speechless at how easy it was for me to do all this painstaking and tedious work. Awesome! ### 5/5 — Change country codes excellent *2018-10-07, version 4.2.1* Works great just make sure you check all contacts and put the right country code Also erase duplicates great ### 5/5 — Professional *2018-09-30, version 4.2.1* I have been amalgamating my google contacts with my iCloud contacts. Other contact mergers left behind a dirty trail of contacts with duplicate numbers within the same contact. This app cost a few dollars but it was worth far more than the other apps because it took care of this problem. It also showed exactly what the merged contact would look like before the fact. One can select which contacts to exclude from the merges or clean ups that this app is capable of. Very professional. --- *Data collected daily from the US App Store and indexed by [AppsHunter](https://appshunter.io/). User reviews are verbatim App Store reviews. Ratings, prices and chart positions refresh continuously; this snapshot is from 2026-06-10.*