# Certificate Watch

> Warns when TLS certificates change over time.

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

## Overview

- **ID:** `certwatch`
- **Platform:** Firefox
- **Type:** Firefox add-on
- **Status:** Available
- **Publisher:** PilzAdam
- **Category:** privacy-security
- **Daily users:** 51
- **Weekly downloads:** 1
- **Rating:** 5.00 / 5 (2 ratings)
- **Version:** 1.12.0
- **Last updated:** 2019-12-01
- **First published:** 2019-08-12
- **Size:** 48 KB
- **Data as of:** 2026-09-09
- **Store listing:** [Firefox Add-ons Store](https://addons.mozilla.org/firefox/addon/certwatch/)
- **Website:** [https://github.com/PilzAdam/CertificateWatch/issues](https://github.com/PilzAdam/CertificateWatch/issues)

## Description

Certificate Watch is a Chrome extension designed to enhance your online security by monitoring TLS certificates presented by websites. It stores the initial certificate of each visited domain and warns you if any subsequent changes occur, helping you detect potential security threats. The extension icon indicates whether a certificate is stored, new, or changed, allowing you to review and manage certificate updates easily.

This tool follows the Trust On First Use (TOFU) model by automatically trusting the first certificate it encounters per domain. It doesn't validate certificates—that's handled by your browser—but it alerts you to changes so you can make informed decisions. While it does not block connections, it serves as a valuable countermeasure against attacks involving compromised certificates, empowering you to stay aware of your connection security.

## Rankings

- #15,879 — Overall
- #28 — watch
- #110 — match
- #163 — education
- #189 — catalog
- #189 — education

## Permissions and access

### Permissions

- `https://*/*`
- `wss://*/*`
- `webRequest`
- `webRequestBlocking`
- `storage`
- `unlimitedStorage`

## Safety

- **Risk impact:** Moderate 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).

## Similar extensions and apps

- [SSL Watcher](https://chrome-stats.com/d/ssl-watcher) — 13 users
- [CertWatch Pro](https://chrome-stats.com/d/certwatch-pro) — 1 users
- [Certificate Trust](https://chrome-stats.com/d/certificate-trust) — 120 users, 4.00 / 5
- [Certificate Pinner](https://chrome-stats.com/d/certificate-pinner) — 60 users, 4.40 / 5
- [Anti Certificate Spoofing](https://chrome-stats.com/d/anti-certificate-spoofing) — 4 users, 4.67 / 5
- [Certi Watch](https://chrome-stats.com/d/certi-watch)
- [CertBadger](https://chrome-stats.com/d/certbadger) — 1 users
- [SSL Expiry Alert](https://chrome-stats.com/d/ssl-expiry-alert) — 7 users
- [Cert Canary](https://chrome-stats.com/d/cert-canary) — 1 users
- [CertMonitor](https://chrome-stats.com/d/certmonitor) — 1 users
- [cerdicator](https://chrome-stats.com/d/cerdicator) — 2 users
- [Cert Monitor](https://chrome-stats.com/d/cert-monitor)

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