Live Viewport and Media Query
Read the current local viewport and build a CSS breakpoint as the browser resizes.
Enabling local controls…
1. Source and settings
Local processing only; nothing is fetched, executed, uploaded or persisted. Each field32KiB; complete output1MiB. CPU work uses a cancellable Worker:10s startup/1s processing. Editing clears old results and exports.
Model, limits and sources
CSS pixels, not physical hardware pixels. Around uses current width±padding (minimum0); min/max use current width. Screen/DPR are browser-reported hints. No sensors or device permissions. Resize listeners are removed on unmount.
Source controls inspected2026-10-19; model reviewed2026-10-19.
2. Complete result
Waiting for the local browser viewport.
Choose an operation and process the input.
How to use this tool
Enter local input, review the explicit options and model, then run and export the complete result.
When not to use it
CSS pixels, not physical hardware pixels. Around uses current width±padding (minimum0); min/max use current width. Screen/DPR are browser-reported hints. No sensors or device permissions. Resize listeners are removed on unmount.