Who should use Custom CSS?

Custom CSS is a consumer product built for firefox users and web developers.

Does Custom CSS have a free plan?

Yes — Custom CSS is free to use.

What platforms does Custom CSS run on?

Custom CSS runs on the web and embeddable surfaces.

Is Custom CSS still active?

Unverified. Custom CSS 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 Custom CSS?

Similar projects tracked by PulseGate include Custom CSS, Your Custom Css, and CSS Override.

Who develops Custom CSS?

Custom CSS is developed by orbitalfetch.

How long has Custom CSS been around?

Custom CSS first shipped in 2024.

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Custom CSS

Name: Custom CSS
Author: orbitalfetch

mozilla.orgBrowser DevTools & extensions

Custom CSS is a Firefox browser extension that lets users overwrite the CSS of webpages. It is intended for Firefox users and web developers who want to customize page appearance or test style changes directly in the browser.

FreeWebEmbeddable

Visit mozilla.org

2alternatives

4features

2024since

Overview

4 features

In the Browser DevTools & extensions space, Custom CSS takes a focused approach. It focuses on overriding webpage styles without manually modifying site files or using developer tools. It is built as a consumer product for firefox users and web developers. Custom CSS costs nothing to use. It runs on the web and embeddable surfaces.

Behind Custom CSS is orbitalfetch, and it first shipped in 2024. Among its 4 catalogued features are Custom CSS injection, page style overrides, and website access. 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 CSS injection
Page style overrides
Website access
Browser tab access

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

Indexed19 Sep · 02:27 UTC
Custom CSS verified via Firefox Add-ons
Source: Firefox Add-ons · Open

Frequently asked questions about Custom CSS

What does Custom CSS do?: Custom CSS focuses on overriding webpage styles without manually modifying site files or using developer tools. It is catalogued under Browser DevTools & extensions on PulseGate.
Who should use Custom CSS?: Custom CSS is a consumer product built for firefox users and web developers.
Does Custom CSS have a free plan?: Yes — Custom CSS is free to use.
What platforms does Custom CSS run on?: Custom CSS runs on the web and embeddable surfaces.
Is Custom CSS still active?: Unverified. Custom CSS 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 Custom CSS?: Similar projects tracked by PulseGate include Custom CSS, Your Custom Css, and CSS Override.Custom CSS Your Custom Css CSS Override
Who develops Custom CSS?: Custom CSS is developed by orbitalfetch.
How long has Custom CSS been around?: Custom CSS first shipped in 2024.

At a glance

Pricing: Free
Platforms: Web
Built for: Firefox users and web developers
Model: B2C
Solves: Overriding webpage styles without manually modifying site files or using developer tools.

Registered as

Firefox Add-ons: custom-css-editor

Developer

orbitalfetch

Index record

Indexed: 19 Sep 2026
Lifecycle: Alive
Last seen: 19 Sep 2026

Identity audit (13)

Slug: custom-css-mozilla-org-a877ho
Lifecycle state recorded: 19 Sep 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 19 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: 19 Sep 2026
Canonical URL: https://addons.mozilla.org/en-US/firefox/addon/custom-css-editor

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