On September 9, 2026, Apple announced iPhone Duo, its first foldable. It goes on sale on October 23 in more than 70 countries and regions, from $1,999 in the U.S. (Apple Newsroom, Apple unveils iPhone Duo, 2026). App Store Connect already lists two new iPhone Duo screenshot sizes, one per display. You can't upload either one yet.
iPhone Duo ships October 23 on iOS 27.1 with two new screenshot sizes: 1398×2034 px outside and 2007×2853 px inside. Previews stay at 886×1920. App Store Connect won't take Duo uploads until "later this year" (Apple, 2026). Don't stretch your 6.9-inch set: it crops about a third of the frame. Build now, ship with a new version.
Your iPhone screenshots are about 2.17:1, height to width; both Duo displays are near 1.42:1. Duo runs iOS 27.1, so it also gets the new iOS 27 product page headers. This guide covers what's unique to the foldable.
Key Takeaways
- Outer 1398×2034, inner 2007×2853, previews 886×1920 (Apple, 2026). No upload date yet.
- Apple doesn't list Duo screenshots as required.
- Resizing a 6.9-inch shot crops about a third (our arithmetic). An iPad 13-inch layout is within about 6%.
- One master layout, two moments: glance outside, canvas inside. Show only what you've shipped.
- Stage a version for upload day, and localize first for launch-wave markets.
Apple's spec pages still say Duo uploads "will be available later this year," and the latest release notes (September 23 and 24) don't mention Duo (Apple, release notes). We'll update this post when uploads open.
Before you begin: what has Apple published for iPhone Duo, and what's still missing?
In 2026, Apple added iPhone Duo screenshot and app preview specifications to App Store Connect on September 9, with a new Human Interface Guidelines page. Xcode 27.1 beta and Figma and Sketch design kits followed on September 18 (Apple, App Store Connect release notes, 2026; Apple Developer News, Build for iPhone Duo with new resources, 2026). Apple hasn't opened uploads or said how Duo product pages use the assets.
Our ledger, checked on September 25, 2026:
| Item | Status |
|---|---|
| Screenshot and app preview sizes | Confirmed (Apple specs) |
| On sale October 23, on iOS 27.1 | Confirmed (Apple Developer News, Sep 16) |
| Xcode 27.1 beta, Duo simulator, design kits | Available since Sep 18 |
| Duo uploads in App Store Connect | Not open; "later this year" |
| Whether Duo screenshots are required | Not stated; no requirement line |
| What Duo shows before you upload Duo sets | Not stated |
| One media slot for both displays, or two | Not stated |
| How previews are framed on Duo | Not stated |
| Duo sets in PPO tests or custom product pages | Not stated |
| Duo as its own device in App Analytics | Not stated |
Have ready:
- Xcode 27.1 beta, Apple's Duo design kits and a build on the iOS 27.1 SDK.
- A role that can upload media: Account Holder, Admin, App Manager or Marketing (Apple, Upload app previews and screenshots).
Step 1: What are the iPhone Duo screenshot and app preview sizes?
In 2026, Apple's screenshot specifications set iPhone Duo at 1398×2034 px (2034×1398 landscape) for the outer display and 2007×2853 px (2853×2007 landscape) for the inner display. App previews use the standard iPhone 886×1920 or 1920×886 (Apple, Screenshot specifications, 2026; Apple, App preview specifications, 2026).
Outcome: four artboards and one preview canvas.
| Asset | Portrait | Landscape | Height ÷ width |
|---|---|---|---|
| Outer display screenshot | 1398×2034 | 2034×1398 | 1.45 |
| Inner display screenshot | 2007×2853 | 2853×2007 | 1.42 |
| App preview (accepted) | 886×1920 | 1920×886 | 2.17 |
Standard rules apply: one to 10 .jpeg, .jpg or .png screenshots with no transparency. The inner spec is about 6.9% per side bigger than the 1878×2670 panel (Apple, iPhone Duo tech specs); by our arithmetic, it's the 3x point size. Export at the spec size.
Apple lists both sizes under one "iPhone Duo" row. Is that one media slot or two? We won't know until uploads open. For other devices, see screenshot sizes for every other iPhone and iPad.
Height ÷ width by canvas (portrait)
Check: each export shows the exact pixel size and no alpha channel.
Step 2: Why can't you just resize your iPhone screenshots?
Because the shape and the UI are both wrong. By our arithmetic from Apple's 2026 specifications, fitting a 6.9-inch screenshot (1320×2868) to Duo width crops 33.0% of its height on the outer size and 34.6% on the inner. Fitting it to height leaves the same share of the width empty. The inner size also needs a 1.52× upscale, which softens UI text.
Outcome: a numbers-backed case for native Duo captures.
On September 24, 2026, we compared Apple's portrait sizes: 6.9-inch iPhone 1320×2868 (2.17), Duo outer 1398×2034 (1.45), Duo inner 2007×2853 (1.42) and iPad 13-inch 2064×2752 (1.33). Crop share is 1 minus the Duo ratio divided by the source ratio. It's arithmetic, not a device measurement.
Resizing into Duo canvases, drawn to scale
The UI is the bigger problem. The outer display is "wider and shorter" than other iPhones. So the system moves toolbars and tab bars to the side "to preserve vertical space for content" (Apple HIG, Designing for iPhone Duo, 2026). A stretched iPhone shot shows none of that.
On Duo the UI isn't the same across sizes, so the usual shortcut of letting Apple scale one set down doesn't fit. Guideline 2.3 also asks that screenshots "accurately reflect the app's core experience" (Apple, App Review Guidelines, updated June 8, 2026).
The better template is your iPad set. A 13-inch iPad frame lands within about 6% of the inner canvas and 8% of the outer. Reuse the iPad caption system with Duo UI captures.
Step 3: What should outer-display and inner-display screenshots each show?
Outside, show the fastest path to value. Inside, show what only the extra canvas allows. Treat them as two moments. Closed, Duo is a one-handed phone. Open, it's the canvas someone paid $1,999 for, where Apple's Mail puts a list and a message "side by side." Apple sizes the outer display at "90 percent of the screen area of iPhone 18 Pro" and the inner at "50 percent larger than iPhone 18 Pro Max" (Apple Newsroom, 2026).
Outcome: a two-column brief with captions for each display's first three frames.
The two Duo sizes differ in shape by only about 2.3% (1.45 against 1.42), which squares with Apple's line that "both displays share the same aspect ratio." So build one master layout (caption zone, brand frame, colour) and export it to both sizes; only the UI capture and caption change.
| Outer display | Inner display | |
|---|---|---|
| Show | The fastest path to value, one task per frame | Two panes, side-by-side content, media |
| Captions | Short, one benefit | More room per line; re-typeset |
| UI must include | Bars on the side | The split layout you've shipped |
| Don't show | A bottom tab bar | A two-pane layout you haven't built |
Unfolded, Duo is 6.48 inches wide by 4.64 tall (Apple, iPhone Duo tech specs, 2026), so the inner display opens in landscape. How the App Store lays out landscape shots on Duo isn't documented. Default to portrait unless your game or video app runs landscape.
Show only the layout you've shipped
Your screenshots should match the build people will download. Apps built with Xcode 26 or earlier don't "extend under the status bar and camera" on Duo (Apple, Preparing your app for iPhone Duo, 2026). If your inner layout is still a stretched phone layout, don't market two panes. The screenshot plan follows the engineering plan.
Here's why the first three screenshots carry the decision. Then check your name, subtitle and first captions in Store Page Preview; it renders iPhone proportions, so use it for copy, not Duo layout.
Step 4: How should you handle app previews on iPhone Duo?
Use the standard iPhone preview size. Apple accepts only 886×1920 or 1920×886 app previews for iPhone Duo, like other modern iPhones (Apple, App preview specifications, 2026). That's a 2.17:1 video on roughly 1.42:1 screens. Apple labels Duo's device resolutions "19.5:9," but 2853×2007 is about 1.42:1, so the label doesn't match the pixels.
Outcome: a preview plan that reads however the store frames it.
Fitted to screen height, a portrait preview would fill about two-thirds of the width (66% inner, 67% outer, by our arithmetic). Apple hasn't said whether it pillarboxes, crops or scales. Rules that hold either way:
- Centre the action and captions.
- Lead with value. Previews "autoplay with muted audio" (Apple, Creating your product page).
- Capture real Duo footage. Guideline 2.3.4 allows only "video screen captures of the app itself."
- Expect fallback. Without a localized preview, Apple shows one "from the next best available language."
Our advice: don't commission a Duo-specific preview until the framing is visible.
Step 5: How do you capture and produce Duo screenshots?
Capture from the iPhone Duo simulator in Xcode 27.1 beta, released September 18, 2026. An independent review checked its Duo profile (Blake Crosley, Xcode 27.1 Beta: Your App in the iPhone Duo Simulator, September 21, 2026). It defines the outer display at 1398×2034 and the inner at 2007×2853, both at 3x. That's a third-party finding, so confirm your own captures.
Outcome: a one-language set, six frames per display, at the exact spec sizes.
- Build on the iOS 27.1 SDK and open the app in Device Hub.
- Capture the outer display closed and the inner display open.
- Seed realistic content, not placeholders (guideline 2.1).
- Drop captures into Apple's Duo design kit or your master layout.
- Export .png or .jpg files with no alpha.
- Name files by locale, display and frame, such as
de-DE_duo-inner_01.png.
Check: sizes match, bars sit on the side in outer captures, and nothing sits in the HIG's "folding region" (Apple HIG, 2026). On a physical Duo, confirm whether inner screenshots save at 2007×2853 or at panel size.
Step 6: How does iPhone Duo change your screenshot localization workload?
Screenshots are set per device size and per localization, and in 2026 App Store Connect supports 50 metadata languages (Apple Developer News, March 31, 2026). A native Duo set adds work to every language, so start where Duo launches first and you already get installs.
Outcome: a ranked list of which localizations get Duo sets first.
| Scenario (8 localizations × 6 screenshots) | Images | vs. today |
|---|---|---|
| Today, iPhone only | 48 | 1× |
| Plus one Duo set (one shared slot) | 96 | 2× |
| Plus separate outer and inner sets | 144 | 3× |
Illustrative arithmetic, not client data.
Duo reaches more than 70 countries and regions on October 23, including China, India, Japan, Germany, Brazil and the U.S., then 28 more on October 30 (Apple Newsroom, 2026). Rank them by the installs they already send. Then decide which languages to localize first, and see which localizations each storefront indexes.
Re-typeset rather than swap text: the wider inner canvas gives German more room per line and lets CJK captions go bigger. Follow the screenshot localization workflow.
Step 7: When should you ship Duo assets, and how do you test them?
Build before October 23 and ship when uploads open. Apple's 2026 help page says that once your app is "submitted for review and approved, you must create a new version to update the screenshots" (Apple, Upload app previews and screenshots, 2026). Keep a version ready to submit with your Duo sets, and confirm the rule still applies when uploads open.
Outcome: a dated plan and a staged version.
iPhone Duo: what's dated, and what isn't
The window may land in holiday build season. Apple's latest holiday notice, from December 2, 2024, warned that "reviews may take longer to complete from December 20-26" (Apple Developer News, 2024). No 2026 dates are posted yet, so fit the Duo version into your Q4 release calendar.
Then test. In 2026, Product Page Optimization runs up to three treatments, one test at a time, for up to 90 days, at 90% confidence (Apple, Product Page Optimization, 2026). Whether a treatment can carry Duo-specific screenshots is undocumented. And would Duo traffic ever reach significance? Test the concept on your main iPhone set and carry the winner over; here's how to run a Product Page Optimization test properly.
Size the prize honestly. TrendForce forecasts about 5 million iPhone Duo units in 2026, a 24.8% share of roughly 20.2 million foldables (TrendForce, September 10, 2026). Small but premium: prioritize Duo sets if your category fits the canvas moment, such as productivity, media, reading or games.
What will we watch after October 23, and which mistakes should you avoid?
It's too early for conversion benchmarks. As of September 25, 2026, no customer has a Duo, and Apple's specs still say uploads open "later this year." Any "Duo screenshot lift" quoted now is a guess. We'll log dated notes on fallback screenshots, preview framing and the upload date. Mistakes to avoid:
- Stretching the 6.9-inch set. It crops about a third. Build native captures.
- Showing a bottom tab bar in outer shots. Outer bars sit on the side.
- Marketing a layout you haven't shipped. Guideline 2.3 applies.
- Making a 1.42:1 preview. It isn't an accepted size.
- Waiting for upload day to start. Produce now and stage a version.
- Calling Duo sets "required." Apple hasn't said so.
Frequently asked questions
What size are iPhone Duo App Store screenshots?
Apple lists 1398×2034 px (2034×1398 landscape) for the outer display and 2007×2853 px (2853×2007 landscape) for the inner display. Use .png or .jpg files without transparency, one to 10 per set (Apple, 2026). Export at those sizes, not at the inner panel's 1878×2670 resolution.
Can I upload iPhone Duo screenshots yet?
Not as of September 25, 2026. Apple's specification pages say Duo upload support "will be available later this year," with no date, and the latest App Store Connect release notes don't announce it (Apple, 2026). Produce the set now and keep a version ready to submit when uploads open.
Are iPhone Duo screenshots required?
Apple hasn't said they are. The Duo row in its screenshot specifications has no requirement line, unlike the 6.5-inch row, which Apple requires when an iPhone app provides no 6.9-inch screenshots (Apple, 2026). Treat Duo sets as a conversion opportunity in the markets and categories where Duo owners matter.
What size is an iPhone Duo app preview?
The same as other modern iPhones: 886×1920 portrait or 1920×886 landscape, 15 to 30 seconds, up to 500 MB and up to three previews (Apple, 2026). How the store frames that 2.17:1 video on Duo's roughly 1.42:1 displays isn't documented yet.
Do I need separate screenshots for the outer and inner display?
Apple lists a separate size for each display, but whether App Store Connect treats them as one set or two won't be visible until uploads open. Plan two captures either way, because the UI differs: bars on the side outside, two panes inside (Apple HIG, 2026). One master layout can serve both.
Can I resize my iPhone 6.9-inch screenshots for iPhone Duo?
Not cleanly. By our arithmetic from Apple's specs, fitting a 6.9-inch screenshot to Duo width crops about a third of its height (33% outer, 35% inner). Fitting it to height leaves a third of the width empty. The UI won't match Duo's layout either. An iPad 13-inch layout is a closer start.
The bottom line
iPhone Duo is a new shape, not a bigger iPhone:
- Specs: outer 1398×2034, inner 2007×2853, previews 886×1920; uploads "later this year."
- Don't resize: about a third gets cropped, and the UI is wrong.
- Two moments, one composition, showing only the layout you've shipped.
- Localize first for launch-wave markets that already convert.
- Stage a version for upload day, and test concepts on your main iPhone set.
Our screenshot and creative testing work covers Duo sets. A free 30-minute call is enough to scope yours, or start with the fixed-price ASO audit.
