TheLinksMaster - SEO & AI SEO Toolkit

A Firefox sidebar that audits the page you are looking at. Ninety-seven checks run inside your browser against that page and its own files, and the panel gives you the score, five category marks and the three fixes to do first — no account, no API keys, nothing uploaded.

Vendor	24Bit System
Platform	Firefox extension, Manifest V3
Add-on ID	`seo-panel@thelinksmaster.com`
Requires	Firefox 140 or newer
Host permissions	None

What it does

You open a page in Firefox — your own site, a competitor's, a client's.
You click the toolbar icon, or press Ctrl+Shift+U.
The auditor is injected into that one tab and reads the document in front of you: markup, headings, links and images, structured data, visible text, the response headers, and the site's own /robots.txt, declared sitemap, /llms.txt and /ads.txt.
Ninety-seven checks are graded and scored on the same rules and weights as our website's reports, so the number in the panel and the number in the full report for the same page agree.
The panel shows the score on a ruler, five category rulers, the critical / warning / passed counts, what it could not measure and why, and the three most serious failures.
Get the full report hands that page address to the website, which runs its own server-side audit and shows you the complete table.

The panel is deliberately a summary. The long report — evidence per check, every one of the ninety-seven, and the CSV export — is what the website produces.

Requirements

Item	Requirement
Browser	Firefox 140 or newer (the current ESR line)
Page	A normal `http(s)` document. Firefox does not allow any extension to read its own pages, local files, `view-source:` or developer-tools URLs, and neither do we.
Account	None. There is nothing to sign in to and nothing to configure before you get a score.
Network	Only the page's own origin. The extension asks for the tab you are standing on because it never talks to any other site.

The extension ships no credentials, no API keys and no analytics identifiers.

Installation

Install TheLinksMaster - SEO & AI SEO Toolkit from its listing on Firefox Add-ons (addons.mozilla.org).
Firefox parks new icons in the toolbar overflow (the » at the right of the address bar). To keep it visible: browser menu → Extensions → the toolkit's gear icon → Move to Toolbar.
Open any web page and click the icon. The panel opens in the sidebar and starts reading immediately.
Optional: Ctrl+Shift+U does the same thing from the keyboard.

Nothing opens by itself on install — the panel's open_at_install is off, so it appears only when you ask for it.

Using the panel

Overall score — one number out of 100, plotted on a ruler with the pass line marked at 75.
Category scores — five rulers: Technical (35% of the total), Performance (20%), Content (15%), Crawlability (15%) and AI visibility (15%). Hover a row for its weight and score.
Counts — critical, warning and passed, plus how many checks could not be measured on this page.
Could not be measured — a button that appears only when something was not measurable, listing those checks grouped by area with the reason each one gave. A panel that could not read a site says so instead of grading it.
Top issues — at most three lines, critical failures before warnings, each the check name plus the detail the check itself reported. When there are more than three failures the header says top 3 of N.
Re-run reads the page again — use it right after you change a template or upload a file.
Settings opens the four options described below.

Open the panel on a different tab and it audits that tab. Switch tabs while it is open and press Re-run.

What it checks

Ninety-seven checks in eleven areas. Every one returns pass, warning, critical or not measured — a check that could not read its input refuses to invent a verdict.

Area	Checks	Examples
On-page	21	Title present and not truncated, meta description length, exactly one H1, heading structure and skipped levels
Crawlability and indexing	15	HTTP status, soft 404, `noindex`, blocked in `robots.txt`, directive conflicts, canonical tag
Performance	13	Browser-measured load time, time to first byte, document weight, subresource requests, DOM size and depth, render-blocking scripts
Content	11	Word count, thin content, text-to-HTML ratio, title terms reused in the body, keyword in title and H1
Structured data	9	JSON-LD readable, required properties, recommended coverage, no retired rich-result types, Open Graph, og:image, Twitter/X cards
Security and response headers	7	`Cache-Control` on the document, frame protection, content-type sniffing, Referrer-Policy, CSP, Permissions-Policy, disclosed server version
Media	6	Alt text present and descriptive, width and height attributes, lazy loading, next-gen formats
Links	6	Internal link share, external link hygiene, descriptive anchors, `target=_blank` isolation, broken links
Site files	5	XML sitemap reachable, sitemap `lastmod`, `robots.txt` quality, `llms.txt`, `ads.txt`
Rendering	2	Raw HTML matches the rendered DOM, mobile signals
AI visibility	2	AI crawlers can reach the site, semantic structure

Get the full report

The button at the bottom of the panel takes the address of the page you are standing on to the website and starts the server-side audit of it. The report opens in a new tab with the complete check table, the evidence behind each finding, the score history for that site and a CSV download.

Click Get the full report.
A tab opens on /free-seo-checker with your page's address already in the field, and the form submits itself.
The address is cleared from the bar before the submit, so pressing Back does not run a second audit.
A few seconds later you are on the scored report for that URL.

Guest audits are rate-limited and the reports they create are published at a shareable link — that is the point of the hand-off. If you want audits kept private, or run across many pages, sign in on the website first. Nothing leaves your browser before you click the button.

Search-results reading

Off by default. When you switch it on and stand on a Google, Bing or DuckDuckGo results page, the panel adds a Search results block.

The header line counts what it read: results found, how many were paid, how many distinct organic domains, and how many full page addresses it resolved.
Each row links to the ranked page. Where an engine wraps the address so only the domain is readable, the row links to that site's root and says so in its title.
Advertisement rows are tagged paid and kept out of the organic tally instead of being counted as competitors.
A domains ranking tally lists the domains appearing most often first, with an ×N where one domain holds several places.
If the page markup changes under the reader and no ranked headings can be parsed, it tells you that instead of showing an empty list.

It parses only the results page already on your screen. It sends no request to the search engine and stores no query.

Settings

Setting	What it does	Default
Tools site	Which installation Get the full report hands the page address to. Point it at your own copy of the tool site if you run one.	`https://www.thelinksmaster.com`
Title min	The shortest page title the title-length check accepts.	30
Title max	The longest it accepts before calling the title likely to be cut off in search results.	65
Search results	Turns the block described above on and off.	Off

These four values are stored in your Firefox profile and apply to every tab. They are the only thing the extension writes down; see the privacy policy.

When something goes wrong

What you see	Cause	What to do
"This page type cannot be audited — it is not a normal http(s) document."	You are on a Firefox page, a local file, `view-source:` or a developer-tools URL, which no extension is allowed to read	Open the page at its normal web address and try again
The could not be measured button appears with several checks in it	The site refused the panel's same-origin reads, or blocked the robots and sitemap path	Nothing to fix in the panel — the server-side report fetches along a normal crawler path and covers those checks
The panel sits on "Reading the page…"	A very large document, or a script on the page that never yields to the auditor	Press Re-run; if one site repeats this, report it with the page address
No Search results block on a results page	The reader is off by default	Settings → switch search results on
The full report opens the website but not on your page	The tools-site setting points at an installation that is not reachable, or is misspelled	Set the tools site back to the default and click again

Limitations

One page per run. It audits the tab you are standing on, not the whole site.
It cannot see anything a browser cannot see: no search rankings, no backlink index, no field Core Web Vitals, no traffic data. The server-side report and your Search Console cover those.
Content behind a login is out of reach unless you are already signed in on that tab; even then the panel marks what it could not read instead of guessing.
Firefox-internal and local-file pages cannot be audited at all. That is a browser rule, not a product choice.
The panel is the summary view; if you want the full table of all ninety-seven checks, use the report.

Data and privacy

Read	The document of the tab you granted access to, plus same-origin requests for its response headers, `/robots.txt`, the sitemap that file declares, `/llms.txt` and `/ads.txt`.
Written	Nothing to any site. The panel changes no page, submits no form and clicks nothing.
Stored	Four settings in your Firefox profile. No page content, address, score or result is stored.
Sent to us	Nothing, until you click Get the full report — then the page address goes to the tools site you configured, which audits it and keeps the report under that site's own privacy policy.
Analytics or telemetry	None. No crash reporting, no pings home, no update check carrying an identifier.

The full text, including the permission-by-permission justification, is in the privacy policy.

Support

Email [email protected] or open a request at support.24bitsystem.com. More about us at 24bitsystem.com.

When reporting a problem, include your Firefox version, the address of the page (or a note that it is private), what the panel showed, and how many checks it listed as not measured. That is normally enough to reproduce it.