# Modus

> Inject user-generated CSS and JavaScript into all webpages.

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

## Overview

- **ID:** `modus-css-js`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Kanon
- **Category:** web-development,appearance
- **Daily users:** 8
- **Rating:** 1.00 / 5 (1 ratings)
- **Version:** 0.0.101
- **Last updated:** 2019-06-07
- **First published:** 2018-10-04
- **Size:** 20 KB
- **Data as of:** 2026-09-16
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/modus-css-js/)

## Description

Modus is a Firefox add-on that enables users to inject their own CSS and JavaScript code into all webpages, giving them the ability to customize the appearance and behavior of websites according to their preferences.

## Rankings

- #36,911 — Overall
- #144 — javascript
- #187 — inject

## Permissions and access

### Permissions

- `storage`

### Content script matches

- `*`

## Safety

- **Risk impact:** Moderate risk impact
- **Risk likelihood:** Moderate 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/modus-css-js)