Who is Screen Sizer for?

Screen Sizer is a B2B product built for developers and QA engineers.

Is Screen Sizer free?

Yes — Screen Sizer is free to use.

What platforms does Screen Sizer run on?

Screen Sizer runs on the web and embeddable surfaces.

Is Screen Sizer still maintained?

Unverified. Screen Sizer 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 Sizer?

Similar projects tracked by PulseGate include Window Resizer, Window Resize, and Simple Window Resizer.

Who develops Screen Sizer?

Screen Sizer is developed by Connor Nee.

How long has Screen Sizer been around?

Screen Sizer first shipped in 2026.

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Screen Sizer

Name: Screen Sizer
Author: Connor Nee

mozilla.orgBrowser DevTools & extensions

Screen Sizer is a browser extension for resizing browser windows to mimic device dimensions and CSS breakpoints. It includes built-in and custom presets, favorites, quick resizing, and JSON import/export for developers and QA teams.

FreeWebEmbeddable

Visit mozilla.org

Overview

8 features

Screen Sizer sits in PulseGate's Browser DevTools & extensions category. It focuses on testing responsive layouts at different device sizes without manually resizing browser windows or using developer tools. It is built as a B2B product for developers and QA engineers. Screen Sizer is free to use. Screen Sizer is available on the web and embeddable surfaces.

Connor Nee builds and maintains Screen Sizer, and it first shipped in 2026. Key capabilities include device presets, custom presets, and favorite presets. The interface is available in 32 languages, including Czech, German, and Greek.

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

Device presets
Custom presets
Favorite presets
Quick resize
JSON import/export
Current dimensions
Dark mode
Light mode

Built with & integrations

Runs on

BrowserEmbeddable

Trust & compliance

Verified signals

HTTPSPrivacy Policy Terms of ServiceFree tierMulti-languageStore-verified publisher

Legal

Indexing history

What PulseGate has recorded for this listing

Indexed13 Sep · 16:40 UTC
Screen Sizer verified via Firefox Add-ons
Source: Firefox Add-ons · Open

Frequently asked questions about Screen Sizer

What does Screen Sizer do?: Screen Sizer focuses on testing responsive layouts at different device sizes without manually resizing browser windows or using developer tools. It is catalogued under Browser DevTools & extensions on PulseGate.
Who is Screen Sizer for?: Screen Sizer is a B2B product built for developers and QA engineers.
Is Screen Sizer free?: Yes — Screen Sizer is free to use.
What platforms does Screen Sizer run on?: Screen Sizer runs on the web and embeddable surfaces.
Is Screen Sizer still maintained?: Unverified. Screen Sizer 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 Sizer?: Similar projects tracked by PulseGate include Window Resizer, Window Resize, and Simple Window Resizer.Window Resizer Window Resize Simple Window Resizer
Who develops Screen Sizer?: Screen Sizer is developed by Connor Nee.
How long has Screen Sizer been around?: Screen Sizer first shipped in 2026.

At a glance

Pricing: Free
Platforms: Web
First seen: 13 Sept 2026
Built for: developers and QA engineers
Model: B2B
Solves: Testing responsive layouts at different device sizes without manually resizing browser windows or using developer tools.

Registered as

Firefox Add-ons: screen-sizer-tool

Developer

Connor Nee

Index record

Indexed: 13 Sep 2026
Lifecycle: Alive
First seen: Sep 2026
Last seen: 13 Sep 2026

Identity audit (13)

Slug: screen-sizer-mozilla-org
Lifecycle state recorded: 13 Sept 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 13 Sept 2026
Timeline basis: Indexed-at chronology (no inferred launch/funding milestones).
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: 13 Sept 2026
Canonical URL: https://addons.mozilla.org/en-US/firefox/addon/screen-sizer-tool

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