Who is Schema M12 for?

Schema M12 is a B2B product built for SEO professionals and web developers.

Yes — Schema M12 is free to use.

What platforms does Schema M12 run on?

Schema M12 runs on the web and embeddable surfaces.

Is Schema M12 still active?

Unverified. Schema M12 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 Schema M12?

Schema M12 is developed by nguyenminhv9.

How long has Schema M12 been around?

Schema M12 first shipped in 2026.

Back to the index

Schema M12

Name: Schema M12
Author: nguyenminhv9

mozilla.orgBrowser DevTools & extensions

Schema M12 is a Firefox browser extension that inspects JSON-LD and Microdata schema markup on the current webpage. It is intended for SEO professionals and web developers reviewing structured data implementation.

FreeWebEmbeddable

Visit mozilla.org

Overview

5 features

Schema M12 is a Browser DevTools & extensions project. It focuses on inspecting and validating JSON-LD and Microdata schema markup directly on webpages. It is built as a B2B product for SEO professionals and web developers. Schema M12 is free to use. It ships for the web and embeddable surfaces.

It is developed by nguyenminhv9, and it first shipped in 2026. Key capabilities include JSON-LD inspection, microdata inspection, and current-page analysis. The interface is available in 32 languages, including Czech, German, and Greek. Schema M12 is currently in beta.

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

JSON-LD inspection
Microdata inspection
Current-page analysis
No data collection
Firefox integration

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

Indexed19 Sep · 04:44 UTC
Schema M12 verified via Firefox Add-ons
Source: Firefox Add-ons · Open

Frequently asked questions about Schema M12

What does Schema M12 do?: Schema M12 focuses on inspecting and validating JSON-LD and Microdata schema markup directly on webpages. It is catalogued under Browser DevTools & extensions on PulseGate.
Who is Schema M12 for?: Schema M12 is a B2B product built for SEO professionals and web developers.
Is Schema M12 free?: Yes — Schema M12 is free to use.
What platforms does Schema M12 run on?: Schema M12 runs on the web and embeddable surfaces.
Is Schema M12 still active?: Unverified. Schema M12 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 Schema M12?: Schema M12 is developed by nguyenminhv9.
How long has Schema M12 been around?: Schema M12 first shipped in 2026.
What languages does Schema M12 support?: The interface is available in 32 languages, including Czech, German, and Greek.

At a glance

Pricing: Free
Platforms: Web
First seen: 19 Sep 2026
Status: 🟡 Beta
Built for: SEO professionals and web developers
Model: B2B
Solves: Inspecting and validating JSON-LD and Microdata schema markup directly on webpages.

Registered as

Firefox Add-ons: schema-m12

Developer

nguyenminhv9

Index record

Indexed: 19 Sep 2026
Lifecycle: Alive
First seen: Sep 2026
Last seen: 19 Sep 2026

Identity audit (13)

Slug: schema-m12-mozilla-org
Lifecycle state recorded: 19 Sep 2026
Verification state: Indexed for public listing
Listing state: Listed: yes
Index status: Included in index
Latest evidence snapshot: 19 Sep 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: 19 Sep 2026
Canonical URL: https://addons.mozilla.org/en-US/firefox/addon/schema-m12

Ship this? Send a correction — no account, and you get a link to follow it.

Similar projects

Closest matches by what these projects do