SEO's Toolbox

by Nico Steiner

17 Add-ons in this Collection

Firebug by Joe Hewitt, Jan Odvarko, others

Rated 4 out of 5 stars 2,593 reviews

907,776 users

Firebug integrates with Firefox to put a wealth of development tools at your fingertips while you browse. You can edit, debug, and monitor CSS, HTML, and JavaScript live in any web page...

Web Developer by chrispederick

Rated 4 out of 5 stars 465 reviews

268,381 users

The Web Developer extension adds various web developer tools to the browser.

Flagfox by Dave G

Rated 5 out of 5 stars 827 reviews

255,139 users

Displays a country flag depicting the location of the current website's server and provides a multitude of tools such as site safety checks, whois, translation, similar sites, validation, URL shortening, and more...

SeoQuake SEO extension by SeoQuake Team

Rated 4 out of 5 stars 242 reviews

31,803 users

Accelerate your SEO efforts on the fly. SEOquake is a free plugin for browsers that provides you with key SEO metrics for a specific page, along with other useful tools such as SEO Audit and many others.

Live HTTP Headers by Daniel Savard, Nikolas Co

Rated 4 out of 5 stars 209 reviews

73,113 users

View HTTP headers of a page and while browsing.

Html Validator by Marc Gueury

Rated 4 out of 5 stars 211 reviews

31,681 users

HTML Validator is a Mozilla extension that adds HTML validation inside Firefox, Mozilla. The number of errors of a HTML page is seen on the form of an icon

For Firefox 56, use 0.974 (see all versions below).
For Firefox 57, see Web Extensions.

ShowIP by Anonymous user f5ac7e

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Rated 3 out of 5 stars 282 reviews

15,785 users

Shows the ip address and additional information about the remote host using
Also Displays Information about your local internet connection.
Privacy note: Data on what host you visit is only sent when you enable remote data.

YSlow by YSlow

Rated 3 out of 5 stars 210 reviews

26,290 users

YSlow analyzes web pages and suggests ways to improve their performance based on a set of rules for high performance web pages. is the official open source website.

LinkChecker by Kevin Freitas

Rated 4 out of 5 stars 86 reviews

8,581 users

Check the validity of links on any webpage.

Accessibility Evaluation Toolbar by Jon Gunderson

Rated 4 out of 5 stars 16 reviews

2,082 users

Support web developers in testing web resources for accessibility features.

SearchStatus by Craig Raw

Rated 4 out of 5 stars 196 reviews

7,095 users

Display the Google PageRank, Alexa rank, Compete ranking and SEOmoz Linkscape mozRank anywhere in your browser, along with fast keyword density analyser, keyword/nofollow highlighting, backward/related links, canonical links, WHOIS, robots and more.

Fangs Screen Reader Emulator by Peter Krantz

Rated 5 out of 5 stars 10 reviews

2,053 users

Fangs renders a text version of a web page similar to how a screen reader would read it. The ambition is to help developers understand how an assistive device would present a website and thereby increase chances of finding accessibility issues early.

SenSEO by Nico Steiner

Rated 4 out of 5 stars 44 reviews

2,083 users

SenSEO is an extension checking the most important on-page-SEO-criteria and calculating a grade of how good your site fulfills these criteria.

Operator by Mike Kaply

Rated 3 out of 5 stars 37 reviews

406 users

Operator leverages microformats and other semantic data that are already available on many web pages to provide new ways to interact with web services.

KGen by Nicolas Froidure

Rated 4 out of 5 stars 29 reviews

1,553 users

KGen (Keyword Generator) allows you to see what keywords are strong on visited web pages for search engines.
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