# Blend In

> Blends in OS-related values in User-Agent HTTP request header & a number of JS properties, so that Firefox (Thunderbird) appears to sites visited as running on the OS being used the most in the world. Thunderbird can also be blended in as Firefox.

Canonical page: [https://chrome-stats.com/d/blend-in](https://chrome-stats.com/d/blend-in)

## Overview

- **ID:** `blend-in`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Reşat
- **Category:** privacy-security,appearance
- **Daily users:** 56
- **Weekly downloads:** 2
- **Rating:** 4.40 / 5 (10 ratings)
- **Version:** 80.0.1autoversioning
- **Last updated:** 2020-09-08
- **First published:** 2011-04-23
- **Size:** 81 KB
- **Data as of:** 2026-09-07
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/blend-in/)

## Description

"Blend In" is a Firefox add-on that blends in OS-related values in the User-Agent HTTP request header and JS properties, making Firefox appear as if it's running on the most widely used OS in the world.

## Rankings

- #15,249 — Overall
- #101 — property
- #123 — value

## Permissions and access

### Permissions

- `webRequest`
- `webRequestBlocking`
- `storage`
- `<all_urls>`

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** High risk impact
- **Risk likelihood:** Low 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/blend-in)