# JS Injector Code

> The \`activeTab\` permission is required to inject user scripts and CSS into the currently active tab when the user explicitly triggers an action (clicking "Run" in the popup, side panel, or context menu). This permission is only act

Canonical page: [https://chrome-stats.com/d/js-injector-code](https://chrome-stats.com/d/js-injector-code)

## Overview

- **ID:** `js-injector-code`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** ValKos
- **Category:** web-development
- **Daily users:** 1
- **Weekly downloads:** 2
- **Version:** 1.0.0
- **Last updated:** 2026-07-15
- **First published:** 2026-07-12
- **Size:** 370 KB
- **Data as of:** 2026-09-05
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/js-injector-code/)
- **Website:** [https://valkos.by/widgets/js-injector/security.html](https://valkos.by/widgets/js-injector/security.html)

## Description

<strong>EN:</strong>
JS Injector is a universal cross-browser extension that allows users to inject custom JavaScript and CSS into any website. It provides a powerful code editor with syntax highlighting, autocomplete, and a library of code snippets for common automation tasks. Users can create scripts that automatically run on specific websites based on URL patterns, customize page appearance with CSS injection, and use the Greasemonkey/Tampermonkey-compatible API for persistent storage and cross-origin requests. The extension includes a side panel editor for live script testing, context menu integration, and full import/export functionality for script portability.

<strong>RU:</strong>
JS Injector — это универсальное кросс-браузерное расширение, которое позволяет пользователям внедрять пользовательские JavaScript и CSS скрипты на любые веб-сайты. Расширение предоставляет мощный редактор кода с подсветкой синтаксиса, автодополнением и библиотекой сниппетов для типовых задач автоматизации. Пользователи могут создавать скрипты, которые автоматически запускаются на определённых сайтах на основе URL-паттернов, настраивать внешний вид страниц с помощью CSS-инъекций и использовать совместимый с Greasemonkey/Tampermonkey API для持久ного хранения данных и кросс-доменных запросов. Расширение включает редактор в боковой панели для тестирования скриптов в реальном времени, интеграцию с контекстным меню и полную функциональность импорта/экспорта для переносимости скриптов.

## Rankings

- #116,515 — Overall
- #71 — inject

## Permissions and access

### Permissions

- `storage`
- `activeTab`
- `scripting`
- `contextMenus`
- `webNavigation`
- `unlimitedStorage`

### Host permissions

- `<all_urls>`

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** High 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/js-injector-code)