SEO's Toolbox

by Nico Steiner

17 Add-ons in this Collection

Firebug by Joe Hewitt, Jan Odvarko, others

Rated 5 out of 5 stars 1,840 reviews

1,949,269 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 5 out of 5 stars 248 reviews

433,921 users

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

Flagfox by Dave G

Rated 5 out of 5 stars 664 reviews

479,011 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...

Live HTTP Headers by Daniel Savard, Nikolas Co

Rated 4 out of 5 stars 170 reviews

134,414 users

View HTTP headers of a page and while browsing.

SeoQuake SEO extension by SeoQuake Team

Rated 4 out of 5 stars 214 reviews

61,525 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.

YSlow by YSlow

Rated 3 out of 5 stars 215 reviews

70,134 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.

Html Validator by Marc Gueury

Rated 4 out of 5 stars 216 reviews

48,194 users

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

For Online HTML 5 validation, you need 0.962

ShowIP by ShowIP Dev Team

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Rated 3 out of 5 stars 286 reviews

40,767 users

Show the IP address of the current page in the status bar. It also allows querying custom information services by IP (right click) and see location and avaiable vouchers for shopping sites. Additionally you can copy the IP address to the clipboard.

LinkChecker by Kevin Freitas

Rated 4 out of 5 stars 78 reviews

15,306 users

Check the validity of links on any webpage.

SearchStatus by Craig Raw

Rated 4 out of 5 stars 193 reviews

17,150 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

4,087 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.

Accessibility Evaluation Toolbar by Jon Gunderson

Rated 4 out of 5 stars 17 reviews

4,892 users

Support web developers in testing web resources for accessibility features.

SenSEO by Nico Steiner

Rated 4 out of 5 stars 41 reviews

5,301 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.

KGen by Nicolas Froidure

Rated 4 out of 5 stars 27 reviews

4,239 users

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

Operator by Mike Kaply

Rated 3 out of 5 stars 36 reviews

1,693 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.
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