Who should use Head Examiner?

Head Examiner is an open-source project built for firefox extension developers.

Does Head Examiner have a free plan?

Yes — Head Examiner is free to use.

What platforms does Head Examiner run on?

Head Examiner runs on the web and embeddable surfaces.

Is Head Examiner still maintained?

Unverified. Head Examiner has not been re-checked since it entered the index, so there is no finding either way — and only a positive finding would say otherwise.

What projects are similar to Head Examiner?

Similar projects tracked by PulseGate include QuickOWL, Lelp, and NoFeed.

Who makes Head Examiner?

Head Examiner is developed by CLU OS.

When did Head Examiner launch?

Head Examiner first shipped in 2019.

Back to the index

Head Examiner

Name: Head Examiner
Author: CLU OS

gitlab.comBrowser DevTools & extensions

Extracts metadata from each page's HEAD, and makes it available to other add-ons, so they don't have to scan each page themselves

FreeWebEmbeddable

Visit gitlab.com

Overview

4 features

Head Examiner is a Browser DevTools & extensions project. It focuses on enabling other Firefox add-ons to access page metadata without redundant scanning. It is built as an open-source project for firefox extension developers. It is available for free. It runs on the web and embeddable surfaces.

Behind Head Examiner is CLU OS, and it first shipped in 2019. Among its 4 catalogued features are metadata extraction, firefox integration, and webExtension support.

Metadata extraction
Firefox integration
WebExtension support
Inter-addon communication

Built with & integrations

Framework

Rails

Hosting

Cloudflare

Auth

supabase_auth

AI providers

openai

Runs on

BrowserEmbeddable

Detected from

Cloudflare: cf-ray header · cf-cache-status header

Trust & compliance

Verified signals

HTTPSFree tierStore-verified publisher

Indexing history

What PulseGate has recorded for this listing

Nothing recorded for this listing in this window.

Frequently asked questions about Head Examiner

What is Head Examiner?: Head Examiner focuses on enabling other Firefox add-ons to access page metadata without redundant scanning. It is catalogued under Browser DevTools & extensions on PulseGate.
Who should use Head Examiner?: Head Examiner is an open-source project built for firefox extension developers.
Does Head Examiner have a free plan?: Yes — Head Examiner is free to use.
What platforms does Head Examiner run on?: Head Examiner runs on the web and embeddable surfaces.
Is Head Examiner still maintained?: Unverified. Head Examiner has not been re-checked since it entered the index, so there is no finding either way — and only a positive finding would say otherwise.
What projects are similar to Head Examiner?: Similar projects tracked by PulseGate include QuickOWL, Lelp, and NoFeed.QuickOWL Lelp NoFeed
Who makes Head Examiner?: Head Examiner is developed by CLU OS.
When did Head Examiner launch?: Head Examiner first shipped in 2019.

At a glance

Pricing: Free
Platforms: Web · Api
Languages: English
Built for: Firefox extension developers
Model: Open source
Solves: Enabling other Firefox add-ons to access page metadata without redundant scanning.

Registered as

Firefox Add-ons: head_examiner

Developer

CLU OS

Live coverage

Identity confidence: High · 90.5
Indexed: 29 Jun 2026
Lifecycle: Unverified
Last seen: 29 Jun 2026

Identity audit (11)

Slug: head-examiner-gitlab-com
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 29 Jun 2026
Timeline basis: Indexed-at chronology. This listing's first-seen date was written by the catalog backfill, not observed here, so it is not treated as a sighting.
Name from: Derived from the project's own page and URL.
Category from: Assigned by a language model.
Languages from: Detected by a language model, checked against the page's own declaration.
Last updated: 29 Jun 2026
Canonical URL: https://gitlab.com/clu-os/firefox-add-ons/HEAD_Examiner

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Also in Browser DevTools & extensions

Same category — not a similarity match