iPhone Duo Testerduoresponsive.com
Direct Email Support

Contact Us

We prioritize direct, transparent communication. No convoluted ticketing systems or mandatory sign-ups — simply drop us an email and a member of our engineering team will get back to you.

Average reply time: 24–48 hoursGlobal Developer Support

Email Channels

Select the most relevant address for your inquiry to reach the right engineer:

General & Technical

Developer Support

For questions about dual-screen CSS media queries, viewport segments, simulator usage, and general feedback.

Compose Email
Catalog Additions

Device Profile Requests

Want a newly launched smartphone, foldable, or tablet added? Send us the model name and display specifications.

Compose Email
Engineering

Bug Reports & Discrepancies

Found a rendering glitch or hinge calculation discrepancy? Email us with steps to reproduce and target URL.

Compose Email
Compliance

Privacy & Legal Inquiries

Direct communication for data protection inquiries, security reviews, and legal correspondence.

Compose Email

What to include in your email for faster resolution

To help us debug simulator issues or add new device profiles swiftly, including any of the following details in your message is immensely helpful:

1. Target Website URL

If reporting a layout or display bug, provide the page link or confirm if it's on localhost.

2. Device Model & Posture

Specify the exact device (e.g. iPhone Duo, Surface Duo, Z Fold 6) and posture mode (unfolded, split, landscape).

3. Browser & Operating System

Your desktop environment (e.g., Chrome 130 on macOS, Safari 18, Edge on Windows 11).

4. New Device Specifications

For new device requests, share screen resolution (pixels), viewport points, and DPR if available.

Frequently Asked Support Questions

Quick answers to common questions about testing websites in our simulator:

Why does my website say 'Refused to connect' or appear blank in the tester?▼
Websites that configure HTTP security response headers like X-Frame-Options: SAMEORIGIN, X-Frame-Options: DENY, or CSP frame-ancestors 'none' explicitly block their pages from being embedded in iframes. For local development, remove or relax these headers on staging, or use browser developer extensions to test staging environments.
Can I test localhost or internal corporate intranet URLs?▼
Yes. Because DuoResponsive executes 100% client-side in your local browser, you can enter http://localhost:3000, http://127.0.0.1:5173, or internal IP addresses directly. Your computer resolves them without sending traffic to external servers.
How do I request a new mobile device or foldable to be added?▼
Send an email to devices@duoresponsive.com with the device brand, model, screen resolution, and physical viewport dimensions. We update our catalog regularly.
Is DuoResponsive free for commercial use and client presentations?▼
Yes, 100% free. Developers, designers, and agencies are free to use DuoResponsive to audit, debug, and demonstrate mobile and dual-screen responsiveness on commercial client deliverables.