# DUO LINK 4 — user reviews > 110 indexed App Store user reviews of DUO LINK 4 by PNY, rated 2.10/5 from 498 ratings. - Source: https://appshunter.io/ios/app/duo-link-4/id1103672387/reviews - App overview in markdown: https://appshunter.io/ios/app/duo-link-4/id1103672387.md - Rating breakdown: 5★ 86 · 4★ 33 · 3★ 25 · 2★ 38 · 1★ 316 ## What do users think of DUO LINK 4? Overall sentiment: negative **Pros** - 🚀 Efficient file transfer - 💡 Useful for freeing up phone storage - 👍 Straightforward to use **Cons** - 🐛 Frequent app crashes - 🔍 Confusing or limited UI - 🔌 Compatibility issues with newer devices - 💾 Data loss or corruption **Commonly reported bugs** - App fails to detect connected device - Transferred files not visible or accessible - Inconsistent behavior when renaming folders **Most requested features** - Add 'select all' option for photos/files - Support for more file formats - Improve iPad app experience - Integrate with native Files app ## Newest reviews (19 of 110) ### 2/5 — Update the app! *2026-03-09, version 1.0.86* This works if you have the lightning version, but if you try to use the USB-C version it doesn’t. Other companies have similar apps that work for the USB-C as well so I wish y’all would pay attention & do the same. Tech support hasn’t really been helpful other than telling me to manually move them over, but even then if I select all I can’t unless I do them in multiple small batches which is time consuming. ### 2/5 — Great device, but the app... *2025-08-05, version 1.0.86* I was checking my storage and this app takes up 45GB of space on my phone. If the purpose of the USB drive is to reduce phone storage, why does the app take so much? ### 3/5 — Picture in Picture *2025-06-27, version 1.0.86* Please update the app and add Picture in Picture. Please fix this app ### 2/5 — it was working great but... *2025-02-08, version 1.0.86* Once this clever gizmo got full, I couldn't empty it! Even after I deleted everything on it, it still says it's full. I might have deleted the files incorrectly using my laptop or something like that but I can't find any way to reset or reformat it-- and when I try and copy files onto it, it acts like their copied but then there is nothing there. Help!?! ### 2/5 — Not compatible *2024-09-27, version 1.0.86* Worked great with older iphone. New phone with usb-c not compatible, even trying multiple lightening to usb-c converters ### 2/5 — Needs lots of fixing *2024-09-09, version 1.0.86* I only got this to free up space from all the pictures I take and it has completed that task but keeping the pictures it hasn’t it has corrupted photos and photos have turned up missing that were transferred glad they weren’t much important but still upsetting that this happened cuz they were helpful things to see and look at. Now that I know that this happens I’m just going to use this as a transfer tool if I find out it will work that way without deleting or destroying my photos. Would also be nice if I could just save apps to this device to have more storage for that but it doesn’t really work that way. ### 1/5 — Worst Set Up Possible *2024-05-06, version 1.0.86* For anyone with the foresight to find out about this app before buying any PNY products relying on this app, clear as far away as possible. Not only are you forced to use this app (since the Duolink device I bought does not show up on the “Files” app), the app itself has the clunkiest, most unintuitive UI I’ve seen in a long while. From the looks of things, it isn’t getting updated anymore with anything worthwhile. The only thing that would make me change my opinion about this app and the duolink USB device is if an update allows it to show up in the standard iOS Files app on iPhone and iPad. ### 2/5 — Not detecting that it is plugged into iphone! *2024-04-26, version 1.0.86* Works fine on my pc but not detecting it is plugged into the iphone. It needs an software update! I’ve been using it just fine since I bought it, no issues until now. I need to transfer and it doesn’t detect it is plugged into my iphone. I have a iphone 7+. I will change my review to a 5 star when it is fixed. Thanks ### 1/5 — Complete waste of money! *2024-04-26, version 1.0.86* I thought the duolink would be a convenient usb drive. Instead its functionality is locked behind a dumbed down app made for people that are clueless about tech. Complete waste of money. Maybe its possible to reformat it as a regular drive? But frankly its not worth the time, just use an SSD instead. ### 1/5 — Doesn't work *2024-04-24, version 1.0.86* The app crashes every time, which makes the device worthless. I even tried two different devices and am poorer because of it. If you are reading review before buying the USB device, don't do it. ### 4/5 — Can I use it as a key? *2024-04-21, version 1.0.86* Would like to know if I could use this as a key for the iPhone ### 2/5 — Contacts backup is broken *2024-04-19, version 1.0.86* The last couple of versions have a bug in the contacts backup. The VCF file it produces is scrambled with dozens of phone numbers from other contacts lumped into one. If you depend on this app to save you in a bind, look elsewhere. It worked fine last year but starting about Jan 2024 it is saving garbage data to my contacts backup. ### 2/5 — New user *2024-04-12, version 1.0.86* Does not support all the image file formats for photos that the iPhone produces. Does not cover iPhone nor cannon .raw format. ### 1/5 — Crashing *2024-02-24, version 1.0.86* App keeps crashing when I plug in the duo link drive ### 1/5 — Can’t even give this 1 star. *2024-02-23, version 1.0.86* First off - it is only written in fine print on the back of the box that you need to download an app to use this. Second - I could not get the app to download after multiple attempts. Third - there is no way to get support! So, it is in no way functioning. Really disappointed. Thankfully I can return it. Maybe someone else can have more luck than me, but it is useless to me if it doesn’t work. ### 1/5 — Crash App *2024-02-19, version 1.0.86* The device and concept sounds great on paper. Just plug in and upload photos, videos, etc and viola!. However, my first impression was plugging in the device, download app, crash, open app, crash, and repeat. Not impressed and very disappointed. ### 1/5 — Piece of junk !! *2024-02-12, version 1.0.86* Stays saying loading data at 31.75% complete for hours because it’s Not working !!!!! I advise stay away from this product . Likely the ones at apple store work well . You buy this it takes some of your data . Then you don’t want to return it or give it back when it’s got your personal data ! This product seems to be a mean joke on the customer ! I wish I had listened to the negatives reviewers before opening this and attempting to use it only to abc ail as other ### 1/5 — My first PNY product and my last! *2024-02-08, version 1.0.86* JUNK! Cannot even get it to start as it crashes after it asks for the flash drive to be plugged in. I told myself not to buy this product and to spend the extra money and get a SanDisk. Lesson learned ### 1/5 — USB drive that needs an app *2024-02-03, version 1.0.86* Can’t understand the need for an app that also needs internet connection. Can’t transfer anything from files unless you copy it to the documents folder first. USB won’t show up in files app unless you use an adapter which makes the lightning side of the usb pointless ## Most critical reviews (10 lowest-rated) ### 1/5 — This app suck! *2026-07-12, version 1.0.86* I now understand why there are so many low reviews: the app is difficult to use for transferring information to a thumb drive. I spent hours trying to figure it out without success. ### 1/5 — PNY should be ashamed *2026-05-19, version 1.0.86* I have several PNY hardware devices which have been reliable and well designed. I bought the PNY duolink usb expecting similar results. The usb is fine but to use the usb it is all about the SOFTWARE that works with iPhone. PNY should be ashamed to have such a poor and buggy software associated with their products. Appears they outsourced the software to sell usb hardware and now have a pile of garbage the consumer is left to deal with. DO NOT BUY PNY DUOLINK USB DRIVES - you will regret it ### 1/5 — Worthless *2025-10-04, version 1.0.86* Don’t even waste your money ### 1/5 — Constant Crashing *2025-09-30, version 1.0.86* Appears to read the usb drive and when the progress bar reaches the end, CRASHES! Useless :( ### 1/5 — PNY/DUO LINK *2025-08-26, version 1.0.86* The flash drive and app worked well in the beginning and now the app is not reading what I saved on the flash drive. All the pics I saved are not showing. So frustrating and upsetting if I lost my pictures. ### 1/5 — First impression *2025-04-03, version 1.0.86* Takes forever to load. I am in a hurry and will try again later. The device has been plugged in and the screen has not changed and still instructs me to plug in the device. I’m starting to think I bought a dud. ### 1/5 — PNY Duo-Link 4 never worked 4 me *2024-10-02, version 1.0.86* The app is frustrating. It continually fails to back up files or create new folders. ### 1/5 — Keeps crashing all of a sudden *2024-08-17, version 1.0.86* I don’t understand, I’ve transferred many files before and no issue, all of a sudden it’s not wanting to work. So disappointed ### 1/5 — Frustrated!! *2024-06-26, version 1.0.86* I tried to download photos from my apple phone and the app keeps crashing or restarting itself. What a waist of time and money!!! ### 1/5 — Crashes all the time *2024-05-08, version 1.0.86* Not working. Crashes. It’s a shame that it’s not working ## Most praised reviews (10 highest-rated) ### 5/5 — What’s up with all the complaints??? *2024-09-30, version 1.0.86* Im going to have to agree with another comment that was posted.I don’t have any complaints about the drive it’s dependable the app for makes organization way better. I’m a software developer and I got to say kudos to the creator. ### 5/5 — Five because of my iPhones man functioning. Not the app. *2023-04-27, version 1.0.84* Five more purchases of PNY Duo links for my iPhone. But since the upgrade, update; they at apple won’t allow any more new PNY Duo links won’t work! ### 5/5 — Works just fine *2023-04-02, version 1.0.84* It does exactly what I need it to do ### 5/5 — Works Great! Can't use on MacBook..... *2022-01-20* I love this app! Just purchased a MacBook Pro only to discover that I will still be have to pull the Ipad out just for the use of this. I use my memory stick everyday. This is a little frustrating since I purchased the MacBook to be able to do everything that was impossible because the Ipad was limited. Will you be fixing this issue in the near future? ### 5/5 — Second way to get your items off your iPhone *2021-05-31, version 1.0.82* I just got the app and I am going to use it for sync my photos from my iPhone with any photo transferring apps (Windows PC). And I’m already impressed. ### 5/5 — Exactly What I Wanted *2021-04-26* I see a collection of low rated reviews but I have to disagree, at least as of April 2021. I don’t like dealing with iCloud or anything like it. Yeah, that probably makes me beyond old fashioned nowadays, but I appreciate storing photos on a computer like the fossil I apparently am. I didn’t like the process of upgrading to a new phone because of the need to move photos and videos off the device. Yes, I know iCloud makes things reappear but I still don’t like it. That said, this app/device does exactly what I was hoping — simply plug it in, transfer photos/videos/etc to it — then you can transfer that content to a PC no problem (I presume you could move it to something iOSish too); super conducive to the user, easy UI, very friendly content here. Super thrilled with this purchase. The other reviews sound like a completely different product almost, to a point that I had to doublecheck the product and this app I was so confused as to why or how someone could be unsatisfied. Maybe there was an old bug they fixed or something but this thing is just stellar. Excellent product and service. Thanks! ### 5/5 — Best I’ve used *2020-11-03* I always had a similar product and only bought this on impulse because it had more storage than mine and wasn’t too expensive. (128gb $40) this one is so much easier to use and the other one freezes or fails to transfer if the phone goes to sleep, not this one. I’d recommend this to anyone as a cheap and efficient way to manage your files to and from your phone ### 5/5 — It’s a great way to transfer videos and photos to PC *2020-07-05, version 1.0.74* It is NEVER an easy task to transfer videos or photos from one operating system another. Most of it is confusing or unsupported and “user unfriendly”. This PNY flash drive makes it a lot easier . Not only that, it is an extended storage drive for storing videos, photos and documents. It’s truly a great solution. ### 5/5 — Duo Link *2019-12-27, version 1.0.74* This device is excellent! It did exactly what it was supposed to do. I down loaded video’s / pics off my phone to make room for more memories! I recommended this device to family members. Not sure what other folks are talking about! I didn’t even read directions. Download the app and it’s pretty self explanatory! That’s how simple it is. ### 5/5 — Great for business needs *2019-10-20* I had been looking for a device to transfer business documents; PDF, Word, Excel, etc. between my iPhone / iPad & PCs and this is it! You can create file folders and put the files where you need them. You don't need to have the iPhone / iPad connected with a PC at the same time either…as the Duo Link doesn't require additional power to operate with the iPhone / iPad. Thanks PNY for a great product! --- *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 2026-08-29.*