Who should use Screen Spoofer?

Screen Spoofer is a B2B product built for frontend developers, UI/UX designers, and QA engineers.

Is Screen Spoofer free?

Yes — Screen Spoofer is free to use.

What platforms does Screen Spoofer run on?

Screen Spoofer runs on the web, embeddable surfaces, and Android.

Is Screen Spoofer still active?

Unverified. Screen Spoofer has not been re-checked since it entered the index, so there is no finding either way — and only a positive finding would say otherwise.

What projects are similar to Screen Spoofer?

Similar projects tracked by PulseGate include Agent Spoofer, Screen Sizer, and User-Agent Spoofer.

Who develops Screen Spoofer?

Screen Spoofer is developed by Screen Spoofer.

How long has Screen Spoofer been around?

Screen Spoofer first shipped in 2025.

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Screen Spoofer

Name: Screen Spoofer
Author: Screen Spoofer

mozilla.orgBrowser DevTools & extensions

Screen Spoofer is a Firefox extension that simulates custom and predefined screen resolutions in a popup window. It helps frontend developers, UI/UX designers, and QA engineers preview responsive layouts and device-specific behavior.

FreeWebEmbeddableAndroid

Visit mozilla.org

Overview

6 features

In the Browser DevTools & extensions space, Screen Spoofer takes a focused approach. It focuses on testing responsive website layouts and device-specific behavior without manually resizing browser windows. It is built as a B2B product for frontend developers, UI/UX designers, and QA engineers. Screen Spoofer is free to use. Screen Spoofer is available on the web, embeddable surfaces, and Android.

Behind Screen Spoofer is Screen Spoofer, and it first shipped in 2025. Key capabilities include custom resolutions, device presets, and popup windows. The interface is available in 32 languages, including Czech, German, and Greek.

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

Custom resolutions
Device presets
Popup windows
Exact dimensions
Responsive testing
Secure access

Built with & integrations

Runs on

BrowserEmbeddableAndroid

Trust & compliance

Verified signals

HTTPSPrivacy Policy Terms of ServiceFree tierMulti-languageStore-verified publisher

Legal

Indexing history

What PulseGate has recorded for this listing

Indexed18 Sep · 23:01 UTC
Screen Spoofer verified via Firefox Add-ons
Source: Firefox Add-ons · Open

Frequently asked questions about Screen Spoofer

What does Screen Spoofer do?: Screen Spoofer focuses on testing responsive website layouts and device-specific behavior without manually resizing browser windows. It is catalogued under Browser DevTools & extensions on PulseGate.
Who should use Screen Spoofer?: Screen Spoofer is a B2B product built for frontend developers, UI/UX designers, and QA engineers.
Is Screen Spoofer free?: Yes — Screen Spoofer is free to use.
What platforms does Screen Spoofer run on?: Screen Spoofer runs on the web, embeddable surfaces, and Android.
Is Screen Spoofer still active?: Unverified. Screen Spoofer has not been re-checked since it entered the index, so there is no finding either way — and only a positive finding would say otherwise.
What projects are similar to Screen Spoofer?: Similar projects tracked by PulseGate include Agent Spoofer, Screen Sizer, and User-Agent Spoofer.Agent Spoofer Screen Sizer User-Agent Spoofer
Who develops Screen Spoofer?: Screen Spoofer is developed by Screen Spoofer.
How long has Screen Spoofer been around?: Screen Spoofer first shipped in 2025.

At a glance

Pricing: Free
Platforms: Web
Built for: Frontend developers, UI/UX designers, and QA engineers
Model: B2B
Solves: Testing responsive website layouts and device-specific behavior without manually resizing browser windows.

Registered as

Firefox Add-ons: screen-spoofer

Index record

Indexed: 18 Sep 2026
Lifecycle: Alive
Last seen: 18 Sep 2026

Identity audit (13)

Slug: screen-spoofer-mozilla-org
Lifecycle state recorded: 18 Sep 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 18 Sep 2026
Timeline basis: Indexed-at chronology. This listing's first-seen date was written by the catalog backfill, not observed here, so it is not treated as a sighting.
Name from: Derived from the project's own page and URL.
Category from: Assigned by a language model.
Summary from: Written by a language model from public pages.
Languages from: Detected by a language model, checked against the page's own declaration.
Last updated: 18 Sep 2026
Canonical URL: https://addons.mozilla.org/en-US/firefox/addon/screen-spoofer

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