The best free SEO tools for 2025

In SEO, there’s no such thing as too much information. Whether you’re investigating a specific page, contemplating a new keyword strategy, or planning an outreach campaign, there are always many angles to examine.

As much as paid tools are brilliant and helpful, you don’t always have to spend money to gain good insights or minimise some of the more manual tasks of the job. More importantly, with the rise of AI-powered search through tools like ChatGPT and Google’s AI Overviews, the SEO landscape has evolved significantly in 2025.

As such, we’ve put together a handy list of our top favourite free tools for on-page SEO, technical audits, AI and content optimisation, outreach, general learning, and some useful browser extensions.

Free On-Page SEO Tools

Find keywords with Google Keyword Planner

Keyword Planner remains one of the most popular tools for discovering keywords and getting search volumes. With its local feature, you can easily look up volumes in different countries and cities, which is helpful for targeted campaigns.

Top tip for 2025: Since this tool is designed primarily for PPC, it only gives a range for search volumes per month, which are fairly broad. To see more accurate search volumes, simply add the keyword to your “Plan” and check out the monthly impression – this number is going to be more accurate than the initial range. Also consider using it alongside AI tools for intent analysis.

See ‘People Also Ask’ questions with Answer The Public

Answer The Public is an incredibly useful tool for FAQ and subtopic research. With the ability to see all questions relating to the main query, you can quickly gauge the sub-topics that people are most interested in around a topic. This is particularly valuable in 2025 as Google’s AI Overviews often favour content that answers specific questions.

Check for duplicate content with Copyscape

Duplicate content is always a source of headache, whether it’s caused by similar pages on the same site or other publications using an exact copy of your content. This tool scans the web for you, highlighting any sites that have the same information as yours. With AI-generated content becoming more prevalent, this tool is more crucial than ever.

Create beautiful designs for your on-page copy with Whimsical

Allowing you to create wireframes for both desktop and mobile, this handy tool helps envision and communicate design ideas with great ease. You can also use it to create various other things like mind maps, flow charts, and other projects.

Free Technical SEO Tools

Page speed checks with Google PageSpeed Insights

Check the page speed for both desktop and mobile for any webpage of your site. The tool will give you a score and a handful of suggested improvements, highlighting the most important and urgent ones to fix.

2025 update: This tool remains the king of speed optimisation. The scoring and baseline keeps getting updated, so don’t treat it as a one-time thing to check and improve. We suggest checking your scores every quarter, especially as Core Web Vitals continue to be a crucial ranking factor.

Crawl your site with Screaming Frog

If you have a smaller site, or you just want to crawl a certain section of your site, crawls under 500 URLs are free on Screaming Frog. Discover broken links, analyse meta titles in bulk, check for large images that slow down your page, and much more.

Check the CMS of a site with Builtwith

See what a site is built with in order to know what is achievable, or spy on your competitors. This tool has become even more valuable for understanding the technology stack behind AI-optimised websites.

Compress large images with TinyPNG

Improve your website speed with a simple trick of compressing and reuploading heavy images. This tool supports PNG, JPG, GIF, and even PDF formats. You can often compress file sizes by over 50%!

Check hreflang tags with Hreflang Tags Generator Tool

A staple for any multilingual site, this tool allows for bulk checking hreflang tags and lets you know about any issues across the site.

Free AI-Powered SEO Tools (New for 2025)

Content optimisation with ChatGPT (Free Plan)

ChatGPT has become invaluable for SEO tasks in 2025. Use it for keyword research, content ideation, meta description writing, and understanding search intent. The free plan provides substantial functionality for SEO professionals.

Claude for content analysis – Claude (Free Plan)

Claude excels at retaining context during long conversations, making it excellent for complex SEO strategy discussions and detailed content analysis. It’s particularly useful for reviewing longer content pieces and providing strategic insights.

Check AI Overview visibility with SE Ranking’s AI Overview Tracker

Monitor how your keywords perform in Google’s AI Overviews. This free tool helps you track your visibility in AI-generated search results, which appeared in over 13% of searches by March 2025.

AI content detection with Grammarly

Whilst not exclusively an SEO tool, Grammarly helps ensure your content (whether human or AI-assisted) is polished, error-free, and maintains the quality standards search engines favour for E-E-A-T compliance.

Free Tools for Link Building

Find and validate email addresses with Hunter

One of the most accurate free email address-finders out there, it can be installed as a plugin for Chrome, making the process of finding email addresses for a particular website quick and easy.

See journalist enquiries on a range of topics with Help a Reporter Out

Sign up for custom alerts or dig through the daily reporter requests. You can simply find a topic that’s relevant for you and write a response in the hope that your answer (and website) gets featured.

Find link opportunities with Featured

A newer addition to the link building toolkit, Featured offers a free plan that helps identify digital PR opportunities and journalist enquiries across various industries.

Free Training Tools

Get certified with Google Certification courses – Grow with Google

Learn the ins and outs of Google Analytics, Search Console, writing content, and promoting your site. Best of all, you can earn a free certificate too. The 2025 curriculum now includes modules on AI search and optimising for Google’s AI Overviews.

Learn the tricks of the trade with SEMRush Academy

With courses from industry leaders on a range of SEO, PPC, and paid social topics, you can quickly learn everything you need to know to get started in the field. New courses for 2025 cover AI-assisted SEO and adapting to changing search behaviours.

Watch the most interesting talks online at Brighton SEO

Brighton SEO continues to offer online access to presentations and talks on the hottest topics of the SEO industry from industry experts. The 2025 programme heavily features AI in SEO, E-E-A-T optimisation, and preparing for the future of search.

Essential Browser Extensions for 2025

SEO Minion – Free Chrome extension for quick on-page SEO checks Keywords Everywhere – Free keyword research extension with limited daily searches MozBar – Free toolbar from Moz for instant domain authority and page metrics Web Developer – Comprehensive set of web development tools useful for technical SEO

Free WordPress SEO Plugins

RankMath SEO – The most feature-rich free WordPress SEO plugin available in 2025, offering AI-powered suggestions and comprehensive optimisation features.

Yoast SEO – Still a solid choice with a simple interface, though not as feature-packed as RankMath’s free version.

What’s Changed in 2025?

The SEO landscape has evolved significantly with several key developments:

• AI Overviews: Google’s AI-generated answers now appear in over 13% of searches, making question-focused content more important than ever
• E-E-A-T focus: Experience, Expertise, Authoritativeness, and Trustworthiness have become crucial for ranking, especially with AI-generated content proliferation
• AI search engines: Tools like ChatGPT now rank as the 5th most visited site globally, changing how people search for information
• Core Web Vitals: Page speed and user experience metrics continue to be critical ranking factors
• AI content detection: Search engines have become better at identifying and potentially penalising low-quality AI-generated content

Best Practices for Using Free SEO Tools in 2025

1. Combine multiple tools: No single free tool provides everything you need. Use a combination of tools for comprehensive analysis.
2. Focus on quality over quantity: With AI making content creation easier, quality and expertise matter more than ever.
3. Monitor AI search visibility: Track how your content appears in AI Overviews and AI-powered search engines.
4. Prioritise user experience: Tools that help improve Core Web Vitals and user experience are essential.
5. Stay updated: The SEO landscape changes rapidly. Regularly check for new features and tools.

The key to successful SEO in 2025 isn’t just about ranking on traditional Google searches – it’s about being visible across the entire search ecosystem, including AI-powered search tools whilst maintaining the quality and expertise that both users and search engines value.

Remember: whilst free tools can provide tremendous value, they often have limitations. As your SEO efforts scale, consider investing in premium tools for more comprehensive data and advanced features.