Viewport Emulator lets you pick common device widths or enter a custom size to see an iframe-like frame and a short CSS tip for container-query sized containers.
What Viewport Emulator does
Frames a responsive preview box.
- Device presets
- Custom width/height
- Visual frame
- Container query tip snippet
Who Viewport Emulator is for
- Frontend developers
- Designers checking breakpoints
- Students learning responsive layouts
- Anyone drafting CQ experiments
How to use Viewport Emulator
1. Pick a preset or custom size.
2. Watch the frame dimensions update.
3. Copy the tip CSS if useful.
4. Validate real devices before ship.
Features
- Lightweight local preview
- Related CSS tools
- Honest non-lab scope
- Instant updates
Examples
- 390×844 phone frame.
- 1280 desktop content width.
- Custom 700px container sketch.
Tips and limits
- Not a substitute for Chrome device mode.
- DPR and safe-areas are not simulated.
- Content inside is a placeholder.
- Use real devices for touch targets.
Related tools
FAQ
Can I load my site in the frame?
This version shows dimensions and a placeholder frame, not an arbitrary URL sandbox.
Are presets exact devices?
They are common logical width/height pairs for quick checks.
Extra notes
Viewport Emulator runs entirely in your browser so drafts and secrets never need to leave your device for processing. Keep a backup of long outputs in your own notes if you rely on them for production servers or live events. Accessibility friendly labels come from the module UI strings, and the layout follows the shared BeeForge .bf-tool shell for consistent spacing and buttons.
Support for developers, marketers, and everyday users is the same client-side model: open the page, configure options, copy or download, then paste into your workflow. BeeForge related links on the tool page point to companion utilities so you can move between related generators without hunting the hub.
When you share results with a teammate, paste into a ticket or gist rather than screenshotting alone, so the text remains searchable. If a browser privacy mode blocks clipboard helpers, select the output manually. Local processing also means the tool works offline after the page and scripts have loaded once.
Validate generated configs or hashes in a staging environment before production use. Prefer regenerating secrets after any accidental paste into chat. For teaching sessions, walk through one sample input end to end so students see how live updates and copy buttons behave together.