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Viewport Resizer

mozilla.orgBrowser DevTools & extensions

PulseGate's liveness check found it on 24 Sep 2026; it is registered on Firefox Add-ons and has been in the index since 24 Sep 2026. How this is checked

Viewport Resizer is a Firefox extension for previewing web pages in resizable simulated device viewports. It helps web developers and designers test responsive layouts without relying solely on browser developer tools.

Inferred · not functionally tested

FreeWebEmbeddable
Viewport Resizer preview
Visit mozilla.org
2alternatives
4features
2026since

Overview

4 features

Purpose: Testing responsive web layouts across simulated device viewports without repeatedly resizing browser windows.

Inferred · not functionally tested

Audience: web developers and designers

Inferred · not functionally tested

Functions: Unknown

Interfaces: API: unknown · MCP: unknown · CLI: unknown · Self-hosting: unknown

Recorded constraints: pricing: free · license: Proprietary · platforms: WEB · deployment: browser, embeddable

Constraint provenance is unknown; confirm requirements with the publisher.

Record sources: addons.mozilla.org · addons.mozilla.org. These links do not verify the individual claims.

Viewport Resizer is a Browser DevTools & extensions project. Inferred · not functionally tested: It focuses on testing responsive web layouts across simulated device viewports without repeatedly resizing browser windows. Inferred · not functionally tested: It is built as a B2B product for web developers and designers. Basis unknown · not verified: Viewport Resizer costs nothing to use. Basis unknown · not verified: It runs on the web and embeddable surfaces.

NITH builds and maintains Viewport Resizer, and it first shipped in 2026. Inferred · not functionally tested: Among its 4 catalogued features are resizable viewports, device simulation, and web page preview. The interface is available in 32 languages, including Czech, German, and Greek.

Summary written by a language model from the project’s public pages.

Tasks: Inferred · not functionally tested

  • Resizable viewports
  • Device simulation
  • Web page preview
  • Responsive testing

Topics: Inferred · not functionally tested

Tags
responsive-designviewport-testingfirefox-extensionweb-development

JSON profile · Text profile · Access guide

Built with & integrations

Runs on
BrowserEmbeddable

Trust & compliance

Public signals
HTTPSPrivacy PolicyTerms of ServiceFree tierMulti-languageStore listing found
Legal
Privacy Policy Terms of Service

Indexing history

1

What PulseGate has recorded for this listing

  1. Indexed22 Sep · 23:28 UTC
    Viewport Resizer seen via Firefox Add-ons
    Source: Firefox Add-ons · Open

Frequently asked questions about Viewport Resizer

What is Viewport Resizer?
Inferred · not functionally tested: Viewport Resizer focuses on testing responsive web layouts across simulated device viewports without repeatedly resizing browser windows. It is catalogued under Browser DevTools & extensions on PulseGate.
Who is Viewport Resizer for?
Inferred · not functionally tested: Viewport Resizer is a B2B product built for web developers and designers.
Does Viewport Resizer have a free plan?
Basis unknown · not verified: Yes — Viewport Resizer is free to use.
What platforms does Viewport Resizer run on?
Basis unknown · not verified: Viewport Resizer runs on the web and embeddable surfaces.
Is Viewport Resizer still active?
PulseGate's liveness check found it on 24 Sep 2026.
What are alternatives to Viewport Resizer?
Similar projects tracked by PulseGate include Viewport Resizer Plus, Resize Window & Viewport, and Viewport.Viewport Resizer PlusResize Window & ViewportViewport
Who develops Viewport Resizer?
Viewport Resizer is developed by NITH.
How long has Viewport Resizer been around?
Viewport Resizer first shipped in 2026.

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