12 Best Free SEO Plugins and Tools

Optimisation

The plugins all aim to optimise your content and markup but adding in the specific meta tags for search engines, XML sitemaps, compressing and minifying content for performance as well as offering useful tips while you write.

Yoast SEO

Yoast SEO WordPress Plugin

Yoast SEO is the original WordPress SEO plugin since 2008. It is the favourite tool of millions of users, ranging from the bakery around the corner to some of the most popular sites on the planet. With Yoast SEO, you get a solid toolset that helps you aim for that number one spot in the search results. Yoast: SEO for everyone.

All In One SEO

All in One SEO Pack

Use All in One SEO Pack to optimize your WordPress site for SEO. It's easy and works out of the box for beginners, and has advanced features and an API for developers.

SEO Friendly Images

SEO Friendly Images is a WordPress SEO plugin which automatically updates all images with proper ALT and TITLE attributes for SEO purposes. If your images do not have ALT and TITLE already set, SEO Friendly Images will add them according to the options you set. Additionally, this makes the post W3C/xHTML valid as well.

The ALT attribute is an important part of search engine optimization. It describes your images to search engine and when a user searches for a certain image this is a key determining factor for a match.

TITLE attribute plays a lesser role but is important for visitors as this text will automatically appear in the tooltip when the mouse is over the image.

Keyword Research

These tools allow you to research specific keywords which you can use to target your content and SEO efforts.

Google Keyword Planner

Google AdWords Keyword Tool

This free tool is offered to Google's advertisers for free and anyone can use it. Its main purpose is to show advertisers the keywords they can bid on for their advertising campaigns. It also helps advertisers choose right keywords by showing them an estimate of search volume, number of results, and difficulty level.

As a content marketer or blogger, you can use this data to find keywords with high search volume, high advertiser interest, and more importantly keywords where you can easily outrank all other sites.

Open Site Explorer

Open Site Explorer

Developed by Moz, this free tool allows you to check data for any domain name. You can see who is linking to that domain and what anchor texts they are using. Apart from that, Open Site Explorer offers a wealth of information like top pages, linking domains, which pages are linked on your site, etc.

This tool is free but has daily search limits for each person.

SEOquake

SEO Quake

SEOquake is an SEO toolbar available as a browser add-on for Google Chrome, Mozilla Firefox, Opera, and Safari web browsers. It provides SEO information for any website. These information parameters include page rank, age, last updated, Alexa rank, and many other parameters. It is one of the most downloaded browser add-ons by SEO professionals.

SEOquake toolbar can show you all these parameters for all the search results on the Google search listings. This information can be extremely useful if you are gauging competition for different keywords. You can even download search results in CSV format and prepare your own excel sheets of search data.

Performance

These plugins will help boost the performance of your WordPress powered website, a vital step now that PageSpeed is an important ranking factor. Speed up your WordPress with these top plugins.

WP Super Cache

WP-Super-Cache

This plugin generates static HTML files from your dynamic WordPress blog. After an HTML file is generated your web server will serve that file instead of processing the comparatively heavier and more expensive WordPress PHP scripts.

99% of your visitors will be served static HTML files. One cached file can be served thousands of times. Other visitors will be served custom cached files tailored to their visit. If they are logged in or have left comments those details will be displayed and cached for them.

W3 Total Cache

W3 Total Cache

W3 Total Cache improves the SEO and user experience of your site by increasing website performance, reducing download times via features like content delivery network (CDN) integration.

The only web host agnostic WordPress Performance Optimization (WPO) framework recommended by countless web developers and web hosts. Trusted by numerous companies such as AT&T, mattcutts.com, mashable.com, smashingmagazine.com, makeuseof.com and tens of thousands of others.

WP Smush

WP SmushIt

WP Smush scans every image you upload - or have already added to your site - and cuts all the unnecessary data and scales it for you before adding it to your media library. Unnecessary data includes bulky colour profiles and metadata, and the resize, optimise and compress of all of your images can lead to significantly smaller image file sizes. Smaller file size = quicker to download.

Smush has been benchmarked and tested number one for speed and quality and is the award-winning, proven crowd favourite image optimization plugin for WordPress.

Social

WP Social SEO Booster

WP Social Booster

WP Social SEO Booster adds Facebook Open Graph, Twitter Card and Google Rich Snippets (Microdata / schema.org) to your site to boost your sites search engine visibility. It is the only plugin which does include ALL the different types of microdata which are supported by Google.

Shareaholic

Shareaholic

Shareaholic is the world's leading all-in-one Content Amplification Platform, which includes related content recommendations, social sharing, following, social analytics and site monetization apps such as promoted content, native ads and affiliate links. This module makes it a snap for any website - big or small - to engage and grow their traffic, market their content, gain insights, and monetize their audience, all from one powerful but easy-to-use dashboard.

Instagram Feed

Instagram Feed WordPress Plugin

If you utilise the Instagram platform then the Instagram Feed plugin is a must. With the plugin, you can display Instagram photos from any non-private Instagram accounts, either in the same single feed or in multiple different ones.

Increase engagement between you and your Instagram followers. Increase your number of followers by displaying your Instagram content directly on your site.