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 2,258 reviews

505,105 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 284 reviews

287,626 users

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

Flagfox by Dave G

Rated 5 out of 5 stars 697 reviews

327,254 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 180 reviews

82,851 users

View HTTP headers of a page and while browsing.

SeoQuake SEO extension by SeoQuake Team

Rated 4 out of 5 stars 221 reviews

33,187 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.

Html Validator by Marc Gueury

Rated 4 out of 5 stars 207 reviews

29,953 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

Until Firefox 56, use 0.974 (other versions)
For Firefox 57, see Web Extensions below

YSlow by YSlow

Rated 3 out of 5 stars 210 reviews

34,908 users

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

ShowIP by ShowIP Dev Team

Download Now

Experimental

Rated 3 out of 5 stars 280 reviews

22,441 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 83 reviews

10,984 users

Check the validity of links on any webpage.

SearchStatus by Craig Raw

Rated 4 out of 5 stars 190 reviews

9,230 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

2,628 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 43 reviews

2,622 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.

Accessibility Evaluation Toolbar by Jon Gunderson

Rated 4 out of 5 stars 16 reviews

2,578 users

Support web developers in testing web resources for accessibility features.

Operator by Mike Kaply

Rated 3 out of 5 stars 37 reviews

708 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

2,082 users

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