TwinViewer is a dual-screen photo viewer application.

You can view two different albums simultaneously, compare two photos side by side, pick a better shot, or leave one and delete another.
This is more than just a viewer. You can also create side-by-side combined images, get the detailed EXIF data, etc.

----- HOW TO USE -----

- Swipe left/right to browse next/previous photo.
- Pinch open/close with two fingers to zoom in/out.
- Double tap either one to display in full-screen mode.
- Sync/Async button to switch the sync mode between two viewers.
- Swap button to switch two viewers.
- Grid button to show/hide grid liens.
- Data button to show/hide data such as image size or shooting date.
- Export button to created and share side-by-side images.

----- WHAT'S FULL VERSION? -----

If you upgrade to the full version by in-app purchase, the following restrictions will be unlocked.

- Create and save side-by-side combined images.
- Display detailed EXIF data.
- Remove full screen Ads.

----- REQUIREMENTS -----

* Supported only for iOS 12.0 or later.
* The Privacy Settings for Photos need to be active. Open Settings app > Privacy > Photos > Activate "TwinViewer".

What’s New

Version 10.3

- Fixed coloring issues in dark mode on iOS 13.

Ratings and Reviews

4.3 out of 5
4 Ratings

4 Ratings

cmhawke ,

Best tool for comparing images

Best tool for comparing images that I've used; more convenient and quicker than using the layer method in the typical photo editor. Would be perfect if Recently Deleted were an available folder on the menu but given that most apps don't have that, I'm not complaining! Thanks so much!

Developer Response ,

Thank you for your encouraging comments and I'm sorry I could not meet all your requests.

G77777777777777777! ,

Simply the best app for comparing two photos

Simply the best app for comparing two photos!! The developer regularly maintains the app too.

Developer Response ,

Thank you for your kind comment!

rck_mtn_climber ,

Essential for best pose, fine tuning settings

As a semipro photographer, I am often trying out different apps and different settings to find the optimum one for a particular photographic situation. This app makes it almost trivial to compare two photographs side-by-side. The linked zooming and panning feature is tremendous. I also like that as you swipe through a photo gallery both pictures change in synchronization. So if you have one picture next to another you can move through sets of two very fast.

It is also very helpful for finding the best pose during a portrait session, or in general to find the best image in a series.

The only suggestion I have is to put a filmstrip view at top to make it easier to select a different picture that is close to the current set of pictures that you're using, without having to go all the way back to the Camera Roll. I have 500 pictures in my Camera Roll currently. Let's say I'm looking at picture number 450 compared with picture number 452 and I would like to compare 450 with 454 without jumping back to the Camera Roll. If I could scroll just the right-side picture to 454 using a filmstrip (one that shows me two or three pictures on either side of my current picture) that would be great.


Masako Sakanashi
14.9 MB
Photo & Video

Requires iOS 12.0 or later. Compatible with iPhone, iPad, and iPod touch.


English, French, Japanese

Age Rating
In-App Purchases
  1. Full Version $1.99


  • Family Sharing

    With Family Sharing set up, up to six family members can use this app.

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