Since we mostly develop search engine optimized websites powered by WordPress, I try to contribute to the WP community by sharing the lessons I’ve learned about the platform from time-to-time. Here’s my updated list of must-have WordPress plugins, along with a couple of notes for each one.

Post last updated September 2013.

Akismet (should be installed automatically) – This is a plugin that every WP install should come with. If it doesn’t, add it ASAP to prevent comment spam. Then, get yourself an API key here.

Pro Tip: Akismet is worth paying for, but if you just don’t have the money to pay for it – or if you don’t yet see the amazing value offered – you can get a free key. Just signup for the personal plan and choose to pay $0. Don’t feel like a mooch about it either – this service was free for a very long time, and a lot of people that signed up back in the day (like me) never paid for their API keys. Of course, I bought a key once they started asking for money…

(WP) Antivirus – This is a must-have for determining if your WordPress templates have been modified without your knowledge. It scans daily and will alert you if there’s a change. There are other WordPress security plugins that are highly rated, but since we’re pretty confident in our basic security settings, this is all we typically (but not always) use.

Backup Buddy – Once upon a time, this was the most amazing plugin I’d ever owned. Over the years, it’s become a bit bloated and unreliable. Still, having said all of this, it’s our go-to backup system. You’re able to automatically schedule posts and then upload them to your Amazon S3 account. S3 is awesome, as the likelihood of losing your data here is astronomical.

However, if a premium plugin isn’t on the menu – or if you’d rather spend your money elsewhere – UpdraftPlus is highly regarded and definitely worth looking into.

Comment Redirect by Yoast – Another nice Yoast plugin. Let’s you redirect commentors to a special “thanks for commenting page” that can also encourage them to Like you on Facebook, sign-up for your newsletter, etc.

FD Feedburner – I think Feedburner might not be the *best* solution for offering blog readers an email subscription option, but it’s very good, and the tracking features are nice.

Flare – Looks great, easy to configure, and works well in terms of getting readers to Like/Tweet/+1 your post. Uses the built-in jQuery library and seems to be pretty fast.

Google Analytics for WordPress – Yoast’s plugin offers outbound link tracking, some nice event tracking features (track comments in Google Analytics), and custom variable tracking (you can track GA metrics by user status, post category, etc.). LOTS of features here, but it’s also user-friendly if you’re a beginner.

Gravity Forms – This is a premium plugin that I endorse 100% – it’s far and away the best WordPress form plugin available.

Login Lockdown – This will protect your WordPress install from so-called “dictionary attacks.” It’s a prudent security measure and not at all problematic if you configure it correctly.

Ninja Popups for WordPress – For a whopping $18, you can own one of the nicer “popup” window plugins available. When I say “popup,” I don’t mean annoying windows circa 2003. I mean nice graceful light boxes that contain beautiful sign-up forms, invitations to share or like a post, etc. This plugin is a steal of a deal.

Redirection – You can use htaccess to redirect broken links, etc., or you can just install this awesome little plugin and save a major hassle. This plugin will count redirect requests too, which means you can use it as a crude click tracker.

Pro Tip: Be sure to limit 404 logging…I took down a site once when I set logging to “unlimited” and swamped a database. Funny story, but easily avoidable.

Subscribe To Comments Reloaded – This is one of my favorite plugins – it really works. If you’ve got a blog post that’s generating commentary, people will use this plugin to subscribe…and then they’ll come back to your site every time someone drops a comment. Great tool to help you build an audience.

Vipers Video Quicktags – I’m not wild about the fact this plugin requires it’s own javascript file – even on pages that don’t feature an embedded video – but it’s incredibly easy to use, so I still recommend it.

WordPress Related Posts by Zemanta – This is a new favorite. Super-simple to setup, looks great, boosts on-site SEO, and actually increases time on site / pages-per-visitor. It’s free too. Great plugin…beats similar plugins from Outbrain and NRelate to death.

WordPress SEO by Yoast – This is the best SEO plugin available, only the configuration process isn’t to be taken lightly. You need to evaluate every option on every page of this plugin’s settings menu. It’s not something I would use without reading a great plugin tutorial (like Yoast’s tutorial or this one, or maybe both) or hiring someone who knows SEO backwards and forwards to help you set it up.

WP-Optimize – There are a few plugins that optimize a WordPress database, and some of them might be a better solution. This one works very well, however, and it’s incredibly simple. I typically run the “optimize database” option once a month.

W3 Total Cache – If I can say anything bad about this plugin, it’s that configuration is a PITA (abbreviation). If you want to use the “minification” feature, you really should use the manual setting, and that means a lot of work every time you add or remove a plugin that loads it’s own javascript library or style sheet.

There are also specific recommendations for configuration based on the host you’re with, based on how much control you have over your own server, etc. There are also CDN settings you can monkey with.

Basically, it’s complicated. I’m not saying I don’t understand it (I do), I’m saying it’s not for beginners. You need to pay someone to set this up for you, at least if you want to maximize it’s features. Just make sure your site is mostly finished before you pay for help.

WP-PageNavi – This is a nice little plugin that helps your users – and search engine bots – leaf through your content. A lot of newer themes have similar features installed, but you can add it if your theme uses simple “next page” and “previous page” text links at the bottom of the homepage.