# Crayon: custom CSS injector

> Write CSS rules for any website

Canonical page: [https://chrome-stats.com/d/crayon-custom-css-injector](https://chrome-stats.com/d/crayon-custom-css-injector)

## Overview

- **ID:** `crayon-custom-css-injector`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Morgân von Brylân
- **Category:** web-development,appearance
- **Daily users:** 1
- **Version:** 2.2.0
- **Last updated:** 2026-07-01
- **First published:** 2026-02-25
- **Size:** 104 KB
- **Data as of:** 2026-09-10
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/crayon-custom-css-injector/)
- **Website:** [https://github.com/MorganVonBrylan/crayon-customcssinjector](https://github.com/MorganVonBrylan/crayon-customcssinjector)

## Description

A fork of CustomCSS Injector by Blizz3.
Like CustomCSS Injector, it lets you write CSS rules to be applied to any website. Anything CSS can do, this can do.
Rules can be set globally, for a given domain, or for a specific URL.
Write them in the built-in editor with syntax highlighting (thanks to PrismJS) in the pop-up and hit "Save". No page refresh required!

On top of that, Crayon also provides the following features that (at the time of writing) Blizz3's add-on doesn't:
– Combine global, domain and URL rules: if several rulesets could apply do a page, all of them do, applied in that order (they used to be mutually exclusive).
– An overview page that lets you see all the rules you have set, as well as export/import them.

## Rankings

- #115,430 — Overall
- #135 — inject

## Permissions and access

### Permissions

- `storage`
- `<all_urls>`
- `contextMenus`
- `notifications`

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** Moderate risk impact
- **Risk likelihood:** High risk likelihood

### Analysis details

- Allows access to all websites, posing a significant security risk as it can monitor and modify data from any visited site.
- This extension has low user count. Unpopular extensions may not be stable or safe.

> Some risk analysis details are omitted from this free response. [Upgrade to view the full analysis](https://chrome-stats.com/pricing).

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Source: [Chrome-Stats](https://chrome-stats.com/d/crayon-custom-css-injector)