# Refererer

> The Sidebar displays HTTP Referer headers for all websites in real-time.

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

## Overview

- **ID:** `refererer`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** Libor Benes (Dr. B)
- **Category:** web-development,privacy-security,search-tools
- **Daily users:** 2
- **Weekly downloads:** 2
- **Version:** 1.0
- **Last updated:** 2025-07-23
- **First published:** 2025-07-20
- **Size:** 16 KB
- **Data as of:** 2026-09-07
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/refererer/)
- **Website:** [https://www.linkedin.com/in/LiborBenes](https://www.linkedin.com/in/LiborBenes)

## Description

• Designed for web developers, security researchers, privacy enthusiasts, educators, and students to monitor HTTP Referer headers in real-time.
• Captures URLs with their Referer headers for all web requests, providing an intuitive interface to debug navigation patterns, analyze Referer leaks, or learn about HTTP headers.
• Copy output using Ctrl+A, Ctrl+C, or right-click for analysis in external tools.
• Bold Referer lines, making them easy to distinguish from URLs.
• Auto-scrolls to the latest entry.

Prioritizes security, user safety, and browser integrity, adhering to Mozilla’s standards:
• Minimal Permissions, no unnecessary access to sensitive browser features or user data.
• No Data Collection: Processes headers locally within the browser, with no data stored or transmitted externally, ensuring complete privacy.
• Local Operation: Does not initiate external network requests or rely on APIs/servers. All processing (capturing headers, storing in <code>browser.storage.local</code>, rendering in the sidebar) occurs locally, allowing the add-on to function without external connectivity. Note: Header capture requires active web browsing, as it monitors user-initiated requests.
• Safe DOM Manipulation: Avoids risky methods to prevent vulnerabilities.
• No Third-Party Libraries: Built with pure JavaScript, HTML, and CSS, eliminating dependency vulnerabilities and reducing the attack surface.
• Robust Error Handling.
• Storage Security: temporarily stores headers, with no persistent storage of sensitive data.

User Precautions:
• Referer Leaks: Be aware that Referer headers may contain sensitive information (e.g., URL query parameters). Copying and sharing sidebar content could inadvertently expose private data, so review copied text before sharing.
• Higher Memory Usage: Since there is no limit on the number of captured Referer headers, extensive browsing may increase memory usage, especially on low-RAM systems (&lt;8 GB). Monitor RAM usage and clear the sidebar as needed to optimize performance.
• Temporary Add-On: As a temporary add-on, it requires manual reloading via <code>about:debugging</code>, which ensures no unintended background activity but may interrupt monitoring if not reloaded.
• Browser Interactions: Other extensions (e.g., ad blockers, privacy tools) may modify Referer headers, affecting the add-on’s output. Disable conflicting extensions for accurate monitoring.

Limitations:
The sidebar output may occasionally clear automatically due to browser or extension optimizations. Users should copy important data promptly to avoid loss. Possible reasons include:
• Storage Reset: The background script may reset headers in <code>browser.storage.local</code> due to timeouts or internal limits.
• Browser Memory Management: Firefox may clear DOM content or storage during garbage collection, especially under high memory pressure (e.g., with multiple remote processes).
• Tab Suspension: Firefox’s resource-saving features may reset the sidebar’s state if not persisted robustly.
• WebRequest Listener Issues: Network errors or tab reloads may cause the <code>webRequest</code> listener to reset the headers array.
• Extension Logic: Unintended resets in the background script (e.g., error handling or session management) may clear the sidebar.

## Rankings

- #63,937 — Overall

## Permissions and access

### Permissions

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

### Content script matches

- `<all_urls>`

## Safety

- **Risk impact:** High 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 website URL may be invalid

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

## Similar extensions and apps

- [Smart Referer](https://chrome-stats.com/d/smart-referer) — 2,429 users, 4.08 / 5
- [Referer By Domain](https://chrome-stats.com/d/referer-by-domain) — 5 users, 5.00 / 5
- [Auto Referer](https://chrome-stats.com/d/auto-referer) — 165 users, 4.00 / 5
- [Full Request Referer Header Extension](https://chrome-stats.com/d/full-request-referer-extension) — 3 users, 5.00 / 5
- [Referer Modifier](https://chrome-stats.com/d/referer-modifier) — 816 users, 4.08 / 5
- [URL Security Scanner](https://chrome-stats.com/d/url-security-scanner) — 1 users
- [Referer Control](https://chrome-stats.com/d/referercontrol) — 4,184 users, 3.02 / 5
- [Toggle Referrer (with optional spoofing feature)](https://chrome-stats.com/d/togglereferrer) — 300 users, 4.58 / 5
- [Redirect Inspector — Link & Redirect Checker](https://chrome-stats.com/d/redirect-inspector) — 23 users
- [SourceHide](https://chrome-stats.com/d/sourcehide)
- [Privacy Redirect](https://chrome-stats.com/d/privacydir) — 1 users
- [Referrer policy](https://chrome-stats.com/d/referrer-policy) — 6 users, 5.00 / 5

---

Source: [Chrome-Stats](https://chrome-stats.com/d/refererer)