Best Free Keyword Research Tools for SEO in 2025

Keyword research can make or break the success of any content strategy or pay-per-click campaign.

I’ve seen it all: overspending on tools that promise a world of insights but deliver limited actionable suggestions, ignoring keyword research altogether and getting mediocre results, or underestimating competition for certain keywords and wondering why the clicks never come.

If there’s one thing I’ve learned, it’s that reliable and accurate keyword data is not optional. It’s essential.

But here’s the part we all know too well: Many top-tier keyword research tools are pricey.

I’ve spent significant sums on premium tools, but sometimes you just can’t, or don’t want to, justify the cost.

Fortunately, there are still some great free options that offer valuable insights if you know where to look, how to interpret the data, and when to use these free resources.

I’m here to share my top 12 free keyword research tools and the tasks they’re particularly good at.

Here is an overview of them:

If you are more curious, check out our list of the overall best SEO tools.

Why Free Keyword Research Tools Can Be Enough

Free keyword research tools may not do everything premium solutions can, but they still pack a punch.

When you know analytics fundamentals, even limited data sets can spark fresh content ideas or highlight hidden opportunities. In many cases, I find free tools especially helpful for:

• Generating initial keyword ideas when starting a new site or experimenting with fresh niches
• Identifying trending topics without paying for heavy-duty software
• Validating search volume to decide if a keyword is worth pursuing
• Supporting a broader SEO and content strategy by providing supplementary data

Let’s dive into these 12 free resources you can start using now.

1. SEO.AI

I’ll start with a quick disclosure: I work at SEO.AI, so it’s no surprise I’m mentioning it here.

Even so, I genuinely believe SEO.AI is among the best AI-driven SEO solutions out there. Ranked the #1 platform for AI SEO, it’s specifically built to write and optimize content so it appeals to both search engines and customers alike.

Why I Like It

1. AI-Powered Insight: Whether you’re creating product descriptions, blog posts, or meta tags, SEO.AI’s technology helps you align each piece with Google’s algorithm.
2. Data-Driven SEO Score: You’ll know exactly what needs improvement in your content, just like a skilled SEO analyst would suggest.
3. Built-In AI Chat & Assistants: No more copy/pasting or juggling tabs—everything you need is integrated in the editor, making content generation and optimization super-efficient.

Best Tasks It Assists With

• Supercharging your writing process: The AI writer helps you produce on-brand content quickly and consistently.
• Automating feed optimization: If you have an e-commerce store, the AI can bulk-generate product descriptions that match your tone of voice—no headaches required.
• Streamlining research and feedback loops: With real-time scoring, you’ll spot keyword gaps, get suggestions for related keywords, and see how to improve each piece for search engines.

If you’re ready to leverage AI to speed up your SEO and content workflows, SEO.AI could be your new secret weapon.

2. Google Keyword Planner

I have to start with Google Keyword Planner. This is the granddaddy of all keyword research tools and has been around for ages. Originally built to help advertisers on Google Ads, it’s also quite efficient for organic keyword research.

Why I Like It

1. Direct data from Google: You get search volume ranges right from the source.
2. Suggested phrases and variations: The data can spark new content ideas.
3. Ad-based insights: Although it’s integrated with PPC metrics, those insights can be extremely useful for your SEO strategy as well.

Best Tasks It Assists With

• Rough estimates of keyword volume: While it often gives broad ranges, it’s still a solid starting point.
• Finding related term ideas: It can be a goldmine for variant keywords you hadn’t considered.

3. Google Trends

Google Trends is a secret weapon I’ve used time and again to identify how interest in a keyword evolves.

This free tool can show you search interest over time and compare different keywords to see which one might be on the upswing.

Why I Like It

• Time-based context: No more guessing if a keyword is seasonal or on the brink of exploding in popularity.
• Regional insights: You can see where a keyword is trending around the world (or in specific countries).

Best Tasks It Assists With

• Content planning based on seasonality: If you see “ice cream recipes” spike in June, you know to publish relevant articles or ads around late spring.
• Comparisons between keyword variations: If you’re debating “app development” vs. “mobile app development,” run them both through Google Trends.

4. AnswerThePublic

I remember the first time I used AnswerThePublic—I was amazed by the creative angle it takes. Instead of giving you a static list of keywords, it generates questions, comparisons, and prepositions around your seed term. Let’s say your seed term is “coffee.” You’ll get queries like “why coffee makes me tired” or “which coffee mug keeps coffee hot longest.” These question-based searches are content gold.

Why I Like It

1. Natural language queries: People often type questions into search engines. This tool helps me match my content with actual user queries.
2. Visual mind map: You get a neat visual display of how various phrases connect to each other.

Best Tasks It Assists With

• Brainstorming content and blog post ideas: Perfect for writing long-form guides, FAQs, or in-depth resource pages.
• Identifying trending concerns or problems: If you see repeated queries about a certain aspect, it means there’s demand for an answer.

5. Ubersuggest

Ubersuggest was originally just a straightforward keyword generator, but it has grown into a more diverse SEO tool. The free version imposes some limitations, but there’s enough data to glean insights without committing to a paid plan. In my experience, it’s ideal for quick checks.

Why I Like It

• Search volume and difficulty data: You get an at-a-glance sense of how many times a keyword is searched and how hard it might be to rank for.
• User-friendly interface: It’s straightforward to navigate, even for beginners.

Best Tasks It Assists With

• Surface-level competitor research: While not as in-depth as premium solutions, it still provides competitor keyword data.
• Finding content ideas: The “content ideas” section can show you top-performing pieces around a keyword.

6. KeywordTool.io

I often rely on KeywordTool.io when I want to generate a large list of keyword suggestions fast. The free version is straightforward: type in a seed keyword, and it auto-suggests variations that appear in Google, YouTube, Bing, Amazon, and more.

Why I Like It

1. Multi-platform approach: I can see how a term is searched across different search engines.
2. Long-tail keyword coverage: It scrapes autocomplete data for broad coverage.

Best Tasks It Assists With

• Content ideation for multiple platforms: If you’re branching out, you need to see how people across platforms phrase their queries.
• Quick survey of user intent: The suggestions often identify angles you may not have anticipated.

7. Soovle

Soovle is a lesser-known gem that I often use when I need a broad view of what different search engines suggest.

It’s super minimalistic and certainly lacks advanced analytics, but it excels at quickly revealing a variety of keyword variations from Google, YouTube, Amazon, Bing, Yahoo, and more.

Why I Like It

• Immediate results on a single screen: As soon as you type a keyword, Soovle scrapes autocomplete suggestions.
• No learning curve: It’s literally just a simple search box.

Best Tasks It Assists With

• Brainstorming new content subtopics: Because it pulls from multiple sources, you can see how shoppers, readers, and viewers phrase a query.
• Multi-industry research: If you have an e-commerce site and a YouTube channel, for example, you can see how the keyword differs across platforms.

8. Keyword Surfer

If you like seeing data directly in your browser, Keyword Surfer is worth checking out.

It’s a free Chrome extension that displays search volume right in your Google search results. I’ve used it while performing research on the fly because it eliminates the need to juggle multiple tabs or log in anywhere.

Why I Like It

1. Convenience: You see monthly search volumes without navigating away from the SERP.
2. Local data: Keyword Surfer can indicate volumes in specific countries, helping me tailor content to a particular region.

Best Tasks It Assists With

• Real-time SERP scans: Quickly gauge a keyword’s potential as you’re searching.
• Immediate competitor glimpses: It also displays estimated traffic and backlinks for top-ranking pages.

9. Moz Keyword Explorer (Free Version)

Moz Keyword Explorer offers limited features in its free mode, but it’s still worth a mention.

You’re allowed a few searches per month without a subscription, and it presents data on search volume, difficulty, and related suggestions.

Why I Like It

• Keyword Priority score: A unique metric that balances volume, difficulty, and click-through potential.
• SERP analysis: You can see what’s already ranking and if it matches your intended content angle.

Best Tasks It Assists With

• Occasional in-depth checks: Even a small number of monthly queries can be enough for important keywords.
• Competition analysis: Its SERP breakdown clarifies who you’re up against.

10. Ahrefs Keyword Generator (Free)

Ahrefs is well-known for its robust paid platform, but they also offer a free keyword generator tool that taps into a fraction of their database.

It’s pretty generous for a freebie: You get hundreds of keyword ideas and basic metrics, including search volume and difficulty scores for your seed term.

Why I Like It

1. Trusted data: Ahrefs is recognized as one of the industry standards for link and keyword data.
2. Keyword difficulty insights: Even if it’s a simple measure, it gives you a rough estimate of ranking difficulty.

Best Tasks It Assists With

• Skimming competitor keywords: Quickly see which terms might be fueling your competitor’s traffic.
• Generating content ideas with minimal friction: No complicated sign-up or credit card required.

11. AlsoAsked

If your content strategy includes answering specific questions (and it should), AlsoAsked is a great resource.

It pulls data from Google’s “People Also Ask” section to map out how questions branch into more queries.

Why I Like It

• Hierarchy of questions: Instead of a single list, it shows you how queries connect with each other.
• New angles for content: By seeing the order in which queries appear, you can shape your blog post sections accordingly.

Best Tasks It Assists With

• FAQ section creation: Perfect for including Q&A blocks in your articles or product pages.
• Topic clustering: You can build clusters of content around the queries you see.

12. Wordtracker Scout (Free Chrome Extension)

Wordtracker Scout is another Chrome extension that helps you extract keyword insights from virtually any web page.

Imagine scanning a high-performing article: you activate Wordtracker Scout, and it reveals which words and phrases the content heavily focuses on.

Why I Like It

1. Competitor content analysis: It helps me check which keywords a competitor’s page might be optimizing for.
2. Ease of use: One click and you’re looking at the top keywords for that page.

Best Tasks It Assists With

• On-the-fly content gap analysis: Quickly see how your page differs from a competitor’s in focus.
• Quick inspiration for new articles or sections: The keyword cloud is visually appealing and easy to digest.

A Comparison Table

I often see people ask: “Which of these tools is best for me?” Well, it depends on your goal and how detailed you need your data to be. Here’s a brief summary to help you decide:

FAQ

What is keyword research and why is it important?

Keyword research is the process of identifying and analyzing search terms that people enter into search engines. It is crucial because it helps in understanding the demand for specific topics, guiding content creation, and optimizing for search engines to improve visibility and traffic.

Are free keyword research tools effective?

Yes, free keyword research tools can be effective, especially for generating initial keyword ideas, identifying trending topics, validating search volume, and supporting broader SEO and content strategies.

What are some of the best free keyword research tools?

Some of the best free keyword research tools include SEO.AI, Google Keyword Planner, Google Trends, AnswerThePublic, Ubersuggest, KeywordTool.io, Soovle, Keyword Surfer, Moz Keyword Explorer, Ahrefs Keyword Generator, AlsoAsked, and Wordtracker Scout.

How does Google Keyword Planner work?

Google Keyword Planner provides search volume ranges and suggested phrases directly from Google. It is primarily used for Google Ads but is also effective for organic keyword research.

What makes AnswerThePublic unique?

AnswerThePublic generates questions, comparisons, and prepositions around a seed term, providing natural language queries that align with actual user searches, making it ideal for brainstorming content and blog post ideas.

Can I rely solely on Keyword Surfer for keyword research?

While Keyword Surfer is convenient for real-time SERP scans and provides immediate competitor insights, it should be used as a supplementary tool rather than the sole source for strategic decisions.

How does AlsoAsked enhance content strategy?

AlsoAsked pulls data from Google's "People Also Ask" section, showing how questions branch into more queries, which is useful for creating FAQ sections and topic clustering in content strategy.