One device requires two display plans
The closed configuration behaves as a compact phone surface, while the open configuration introduces a larger canvas. Design reviews should cover both instead of treating the product as one average screen.
iPhone Duo screen size
iPhone Duo has cover display: 5.4″, 1398 × 2034, 460 PPI; inner display: 7.6″, 1878 × 2670, 430 PPI. CSS viewport and DPR references are not published without reliable browser measurements. Its cover and inner displays create two distinct physical testing targets, so responsive QA should treat the device as a state change rather than one average screen.
Cover display (closed)
5.4″
Inner display (open)
7.6″
Cover display (closed)
- Display size
- 5.4″ (13.7 cm) diagonalofficial
- Resolution
- 1398 × 2034 pxofficial
- Pixel density
- 460 PPIofficial
- Aspect ratio
- 1.45:1calculated
- Physical size (display)
- 3.06″ × 4.45″ (7.8 × 11.3 cm)calculated
- Device dimensions
- 84.1 × 117.8 × 11.3 mmofficial
- Release year
- 2026
Inner display (open)
- Display size
- 7.6″ (19.3 cm) diagonalofficial
- Resolution
- 1878 × 2670 pxofficial
- Pixel density
- 430 PPIofficial
- Aspect ratio
- 1.42:1calculated
- Physical size (display)
- 4.37″ × 6.22″ (11.1 × 15.8 cm)calculated
- Device dimensions
- 164.6 × 117.8 × 5.2 mmofficial
- Release year
- 2026
Reliable CSS viewport and DPR measurements are not available yet. The panel resolutions above are hardware pixels and must not be used as CSS breakpoint widths.
Responsive testing plan
iPhone Duo responsive workflow
No verified phone viewport is published for this device. Test both physical display configurations on hardware, record the live viewport, and pair those measurements with nearby layout widths.
Model-specific checks
- Test closed and open configurations as separate targets, then verify that an in-progress task survives the transition between them.
- Measure the live CSS viewport and DPR on shipping hardware before adding automated breakpoint or image-asset expectations.
- Check dialogs, keyboards, media and fixed navigation during posture changes, not only after a clean page load.
Values marked official come from manufacturer specifications; calculated values are derived from them; reference values are developer layout references and can vary with browser, zoom and operating-system settings.
Sources: Apple · Facts reviewed 2026-09-10
Content reviewed 2026-09-10
Model-specific guidance
What this means for layout and testing
Panel pixels are not layout pixels
The hardware resolutions are useful for image detail and density checks, but they do not establish browser breakpoint widths. Record the live CSS viewport before adding this device to automated responsive tests.
State changes deserve continuity testing
Opening the device can change the available display surface while a task is in progress. Forms, media, dialogs and navigation should preserve state and adapt without assuming a fresh page load.
Compare this device
The specifications below come from the device records; the notes explain why each comparison is useful.
| Device configuration | Matched to | Screen | Panel | Viewport / workspace | PPI |
|---|---|---|---|---|---|
| iPhone Duo - Cover display (closed) Current page | iPhone Duo - Cover display (closed) | 5.4″ | 1398 × 2034 | — | 460 |
| iPhone Duo - Inner display (open) Current page | iPhone Duo - Inner display (open) | 7.6″ | 1878 × 2670 | — | 430 |
| iPhone 18 Pro The conventional Pro provides a same-generation phone reference for judging what the closed configuration changes in physical composition. | iPhone Duo - Cover display (closed) | 6.3″ | 1206 × 2622 | 402 × 874 | 460 |
| iPhone 18 Pro The conventional Pro provides a same-generation phone reference for judging what the closed configuration changes in physical composition. | iPhone Duo - Inner display (open) | 6.3″ | 1206 × 2622 | 402 × 874 | 460 |
| iPad mini (A17 Pro) The compact tablet is a useful neighboring form factor for evaluating whether open-state layouts inherit unsupported tablet assumptions. | iPhone Duo - Cover display (closed) | 8.3″ | 1488 × 2266 | 744 × 1133 | 326 |
| iPad mini (A17 Pro) The compact tablet is a useful neighboring form factor for evaluating whether open-state layouts inherit unsupported tablet assumptions. | iPhone Duo - Inner display (open) | 8.3″ | 1488 × 2266 | 744 × 1133 | 326 |
Phones with a similar screen size
Related tools
- Device Screen SizesBrowse sourced screen sizes, resolutions, CSS viewports, DPR and PPI for phones, tablets and laptops, with links to model-level specifications.
- Phone Screen SizesFilterable phone screen size chart with display inches, resolution, PPI, aspect ratio and viewport for the iPhone, Galaxy S and Pixel models tracked here.
- Screen Size ComparisonCompare phone, tablet, laptop and monitor screens as proportional overlays — or against your own screen. True-size mode shows devices at real physical size.
- Viewport Size CheckerSee your browser's CSS viewport size and window size live. Updates as you resize — with current responsive breakpoint for developers.
- Responsive Breakpoint CheckerCheck the current responsive breakpoint live, compare Tailwind and Bootstrap defaults, and copy media queries for common viewport widths.
- Responsive Image CalculatorCalculate responsive image export sizes from CSS pixels and DPR. Generate srcset, sizes and CSS image-set snippets for crisp images.
- PPI CalculatorCalculate PPI from resolution and screen size. Instant results with the formula worked through your numbers, plus physical dimensions and dot pitch.