Short Answer: The best free keyword research tools in 2025 are Google Keyword Planner, Ubersuggest, AlsoAsked, Google Trends, Bing Webmaster Tools, Keyword Surfer, and AI assistants like ChatGPT and Claude.

Introduction

Keyword research hasn’t gone out of style, it’s just evolved. In 2025, ranking in search engines (and being cited in AI-generated overviews) requires more than stuffing pages with keywords. You need to understand how people search, what questions they ask, and which entities (brands, topics, tools) search engines recognize as authoritative.

That’s where free keyword research tools come in. From classic data-driven platforms like Google Keyword Planner to modern AI helpers like ChatGPT, today’s tools make it easier than ever to uncover the queries and concepts that drive visibility. Whether you’re a beginner blogger or a seasoned SEO strategist, these free resources give you the insights to optimize smarter without paying for expensive subscriptions.

Why Free Keyword Research Tools Still Matter

Even as AI reshapes search, free keyword research tools remain essential. They’re not just for beginners or bloggers running lean websites, even seasoned SEOs use free tools to supplement paid platforms like Semrush or Ahrefs.

In 2025, free tools are especially valuable for uncovering questions and entities that power AI Overviews, voice search, and other generative search features. These aren’t just buzzwords, they’re the building blocks of modern SEO.

Keywords vs. Entities in 2025

Traditional keyword research focuses on exact phrases like “best free keyword research tools 2025.” Entities, however, are recognized concepts: “ChatGPT,” “Claude,” “Google Keyword Planner,” or “Keyword Surfer.”

Search engines and large language models don’t just match strings of text, they understand entities and their relationships. That’s why today’s SEO content must cover both:

• Keywords to capture search intent
• Entities to build trust, context, and topical authority

When you write with both in mind, you’re not only ranking in Google, you’re increasing the odds that AI systems will pull your content into summaries and answers.

What to Look For in a Free Keyword Tool

Not all free tools are created equal. Here’s what matters most in 2025:

• Accuracy and Data Depth: Does it give reliable search volumes or competitive insights?
• Long-Tail Discovery: Can it surface less obvious opportunities with lower competition?
• Question-Based Keywords: Crucial for AEO, since AI assistants prioritize direct answers.
• Entity Recognition: Tools that surface brands, topics, or named entities give your content more authority.
• Ease of Use: Some work right inside the SERP, while others require a dashboard or account.
  

7 Best Free Keyword Research Tools in 2025

1. Google Keyword Planner

Google Keyword Planner is still the industry standard for free keyword research. It’s designed for advertisers, but SEOs rely on it for broad search volume ranges and keyword ideas.

⚠️ One important note: You’ll need to set up a Google Ads account and provide a credit card. You won’t be charged unless you actually run ads, but the step is required.

Best for: Reliable keyword volume estimates and ad-focused data.

2. Ubersuggest (Free Version)

Neil Patel’s Ubersuggest continues to offer a decent free tier. You’ll get limited daily searches, but enough to explore keyword ideas, related phrases, and basic competitive data.

Best for: Quick keyword checks and inspiration when you’re just starting out.

3. AlsoAsked (and AnswerThePublic)

In 2025, AlsoAsked is one of the best free tools you can use. Why? Because in the age of AI optimization (AEO), questions are some of the top-performing keywords.

AlsoAsked pulls queries directly from “People Also Ask” boxes, mapping out real questions people type into Google. These are the same questions AI models often surface in overviews. Writing content that answers them directly boosts both your SEO and your chances of being cited by AI.

Best for: Discovering AEO-friendly question keywords that align with voice search and AI-driven search results.

4. Google Trends

Google Trends is perfect for spotting seasonal spikes, breakout searches, and rising interest over time. It won’t tell you exact search volumes, but it’s great for contextualizing when and how people search.

Best for: Seasonal and trend-focused keyword research.

5. Bing Webmaster Tools

Don’t underestimate Bing. With AI-powered search rolling out on multiple platforms, Bing’s Webmaster Tools give you keyword insights beyond Google’s ecosystem. It’s a free way to diversify your research.

Best for: Expanding reach beyond Google data.

6. Keyword Surfer

Keyword Surfer is a Chrome extension that overlays keyword search volume and related terms directly into the Google SERP. It’s lightweight, fast, and requires no login.

Best for: On-the-fly keyword research while browsing search results.

7. ChatGPT and Claude (LLMs)

Finally, the newcomers are AI assistants like ChatGPT and Claude. While they don’t provide hard search volume data, they’re powerful for brainstorming, clustering, and entity mapping.

I use ChatGPT myself: I’ll ask it to research the top SEO keywords for a given topic, and it quickly generates lists of primary and secondary keywords I can build into my blog outline. That saves time and sparks ideas I might not have uncovered through traditional tools.

Best for: Keyword ideation, semantic clusters, and entity coverage to guide your content strategy.

Comparison Table: Free Tools at a Glance

How to Maximize Free Tools

The real power comes from combining tools:

• ChatGPT/Claude → Brainstorm entities, clusters, and related terms
• AlsoAsked → Surface the top questions people ask (AEO)
• Keyword Planner → Validate with volume and competition data
• Keyword Surfer → Check SERPs instantly
• Google Trends → Spot timing and seasonality

This layered approach makes up for the limits of each individual tool.

When It’s Time to Upgrade Beyond Free

Free tools get you far, but if you’re managing a large website or working at an agency level, you’ll eventually need paid tools like Ahrefs, Semrush, or Moz. These platforms provide deeper competitive insights, link data, and more precise tracking.

FAQs

Why are questions so powerful for SEO in 2025?

Because AI systems, voice assistants, and Google’s People Also Ask boxes prioritize direct answers. Optimizing for question-based keywords increases your visibility in both search engines and AI overviews.

Why are entities as important as keywords?

Entities help search engines and AI understand context and authority. Mentioning recognized entities like “ChatGPT,” “Google Keyword Planner,” or “Keyword Surfer” helps establish topical expertise.

Can ChatGPT replace traditional keyword research tools?

Not entirely. ChatGPT is excellent for brainstorming and clustering, but you’ll still need tools like Keyword Planner for hard search volume data.

Is Keyword Surfer accurate enough for SEO?

It’s great for quick insights, but not as detailed as paid tools. Use it to supplement other free or paid platforms.

Conclusion

The best free keyword research tools in 2025 aren’t limited to one platform. They’re a combination of classics like Google Keyword Planner, modern browser tools like Keyword Surfer, question-based tools like AlsoAsked, and AI assistants like ChatGPT and Claude.

This mix ensures you’re covering keywords, entities, and questions, the three pillars of search visibility in the AI era.

👉 Need help building an SEO content strategy that works in 2025? Contact me today and let’s create content that ranks in Google and gets cited by AI.