What is Headers Viewer?

Headers Viewer focuses on inspecting HTTP request and response headers while browsing the web. It is catalogued under Browser DevTools & extensions on PulseGate.

Who is Headers Viewer for?

Headers Viewer is a consumer product built for firefox users and web developers.

Is Headers Viewer free?

Yes — Headers Viewer is free to use.

What platforms does Headers Viewer run on?

Headers Viewer runs on the web and embeddable surfaces.

Is Headers Viewer still active?

Unverified. Headers Viewer 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.

Who makes Headers Viewer?

Headers Viewer is developed by Sarah Sanchez.

How long has Headers Viewer been around?

Headers Viewer first shipped in 2026.

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Headers Viewer

Name: Headers Viewer
Author: Sarah Sanchez

mozilla.orgBrowser DevTools & extensions

Headers Viewer is a Firefox browser extension that displays HTTP request and response headers. It is intended for users and web developers who need to inspect browser network metadata without collecting data.

FreeWebEmbeddable

Visit mozilla.org

Overview

4 features

In the Browser DevTools & extensions space, Headers Viewer takes a focused approach. It focuses on inspecting HTTP request and response headers while browsing the web. Headers Viewer is a consumer product aimed at firefox users and web developers. Headers Viewer is free to use. It ships for the web and embeddable surfaces.

Behind Headers Viewer is Sarah Sanchez, and it first shipped in 2026. Among its 4 catalogued features are request headers, response headers, and header inspection. The interface is available in 32 languages, including Czech, German, and Greek.

Summary written by a language model from the project’s public pages.

Request headers
Response headers
Header inspection
No data collection

Built with & integrations

Runs on

BrowserEmbeddable

Trust & compliance

Verified signals

HTTPSPrivacy Policy Terms of ServiceFree tierMulti-languageStore-verified publisher

Legal

Indexing history

What PulseGate has recorded for this listing

Indexed10 Sept · 01:04 UTC
Headers Viewer verified via Firefox Add-ons
Source: Firefox Add-ons · Open

Frequently asked questions about Headers Viewer

What is Headers Viewer?: Headers Viewer focuses on inspecting HTTP request and response headers while browsing the web. It is catalogued under Browser DevTools & extensions on PulseGate.
Who is Headers Viewer for?: Headers Viewer is a consumer product built for firefox users and web developers.
Is Headers Viewer free?: Yes — Headers Viewer is free to use.
What platforms does Headers Viewer run on?: Headers Viewer runs on the web and embeddable surfaces.
Is Headers Viewer still active?: Unverified. Headers Viewer 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.
Who makes Headers Viewer?: Headers Viewer is developed by Sarah Sanchez.
How long has Headers Viewer been around?: Headers Viewer first shipped in 2026.
What languages does Headers Viewer support?: The interface is available in 32 languages, including Czech, German, and Greek.

At a glance

Pricing: Free
Platforms: Web
First seen: 10 Sept 2026
Built for: Firefox users and web developers
Model: B2C
Solves: Inspecting HTTP request and response headers while browsing the web.

Registered as

Firefox Add-ons: headers-viewer1

Developer

Sarah Sanchez

Index record

Indexed: 10 Sept 2026
Lifecycle: Alive
First seen: Sept 2026
Last seen: 10 Sept 2026

Identity audit (13)

Slug: headers-viewer-mozilla-org
Lifecycle state recorded: 10 Sept 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 10 Sept 2026
Timeline basis: Indexed-at chronology (no inferred launch/funding milestones).
Name from: Derived from the project's own page and URL.
Category from: Assigned by a language model.
Summary from: Written by a language model from public pages.
Languages from: Detected by a language model, checked against the page's own declaration.
Last updated: 10 Sept 2026
Canonical URL: https://addons.mozilla.org/en-US/firefox/addon/headers-viewer1

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