Best free keyword research tools (including free Ahrefs and Semrush alternatives)

What free keyword tools can and cannot do

Free keyword research tools cover more ground than most beginners expect, and less ground than most paid tool comparisons suggest. Understanding the specific gap between free and paid data is more useful than a blanket judgment in either direction.

Free tools do these things well: they surface questions your audience asks, show you how search interest changes over time, reveal which keywords your own site already ranks for, and provide sample volume data for individual keyword lookups. They do not do these things well: bulk keyword exports at scale, accurate monthly search volumes across thousands of terms simultaneously, or deep competitor keyword gap analysis where you need to compare your rankings against five rivals at once.

For a new or small site, those limitations rarely matter. Most sites in their first 18 months benefit more from good keyword selection on 20 to 50 target pages than from analysing a database of 10,000 keyword opportunities they will never have the content capacity to address. Free tools are sufficient for that scale of work.

The tools in this guide fall into four categories: owned-site keyword tools from Google, freemium platforms with meaningful free tiers, browser extensions that add keyword data to Google search results, and AI tools that help with keyword ideation and question mapping. All four have a place in a free keyword research workflow.

For the full context of where keyword research fits in your SEO strategy, the free SEO tools guide covers every major SEO task alongside the free tools available for each one.

Best free alternatives to Ahrefs

Ahrefs is the gold standard for keyword research among professional SEOs. Its keyword database is one of the largest available, its difficulty scores are reliable, and its interface surfaces actionable opportunities quickly. The paid plans are expensive for small teams and solo operators. Several free tools cover parts of what Ahrefs does, though none replicate it fully.

Ahrefs Webmaster Tools

The closest free alternative to Ahrefs is Ahrefs itself. Ahrefs Webmaster Tools is free for any site owner who verifies their domain via Search Console or a DNS record. It provides keyword rankings for your own site drawn from the full Ahrefs database, a site audit that checks up to 5,000 pages, and backlink data for your own domain. The keyword report shows every keyword your site ranks for, its position, estimated traffic, and keyword difficulty.

The restriction is scope: you can only research your own site. You cannot look up competitor keyword rankings or browse keyword databases for new ideas. For sites with existing content that ranks, Ahrefs Webmaster Tools is extraordinarily useful as a free tool. For sites with no content yet, it has little to offer because there is no ranking data to analyse.

Ubersuggest free tier

Ubersuggest, built by Neil Patel, provides a limited number of free daily searches with keyword volume, difficulty scores, and related keyword suggestions. The database draws on Google data and provides reasonable volume estimates for individual keyword lookups. The free tier is restrictive in terms of daily searches and export capability, but for checking individual keyword metrics before targeting a topic, it works adequately. The interface also includes a content ideas section that surfaces existing articles ranking for your keyword, which helps with competitive content research.

Moz Keyword Explorer free tier

Moz's Keyword Explorer allows a small number of free queries per month on a registered free account. It returns search volume ranges, keyword difficulty, organic click-through rate estimates, and related keyword suggestions. Moz's keyword difficulty scores are independently calculated from Ahrefs and Semrush, so they provide a useful second opinion when you are evaluating whether a keyword is realistically targetable. The free limit is low enough that Moz works best as a supplementary tool rather than a primary research platform.

Best free alternatives to Semrush

Semrush's keyword research capabilities centre on its large database, keyword gap tool, and position tracking. Free alternatives that match its depth do not exist, but several cover the most important parts of what Semrush offers at no cost.

Semrush free tier

Semrush's own free account is one of the most useful free alternatives to Semrush's paid plans. It provides 10 keyword lookups per day, each returning search volume, keyword difficulty, cost-per-click data, trend graphs, and related keyword suggestions. For daily keyword checks on high-priority terms before publishing or updating content, 10 lookups are enough if used strategically. The free tier also allows position tracking for up to 10 keywords, which is sufficient for monitoring a small number of target pages.

The free Semrush account requires registration but costs nothing. For someone moving from a paid Ahrefs subscription and looking for free Semrush data to supplement, the free tier provides enough to validate keyword decisions without a full subscription.

Similarweb free tier

Similarweb is not a keyword research tool in the traditional sense, but its free tier provides traffic estimates and top organic keywords for any domain. For competitive research, it shows you what topics drive the most traffic to a competitor's site, which informs your keyword targeting without requiring a full keyword database. The data accuracy is lower than Ahrefs or Semrush at the page level, but at the domain level it provides useful directional signals for free.

SpyFu free tier

SpyFu shows organic and paid keywords for any domain, with limited free access. The free tier reveals the top keywords a competitor ranks for and their estimated monthly traffic, alongside the keywords they have historically ranked for over time. For understanding a competitor's SEO history and keyword strategy, SpyFu's free data provides a useful starting point before investing in a paid tool.

Google's free keyword research tools

Google's own tools provide keyword data that no third-party platform can replicate, because the data comes from Google's infrastructure rather than from crawl estimates. They are not traditional keyword research tools in the sense of browsable databases, but for owned-site research and trend analysis they are irreplaceable.

Google Search Console

Google Search Console is the most valuable free keyword research tool available for sites with existing content. Under the Performance report, it shows every query that triggered your pages in search results over the past 16 months, alongside impressions, clicks, click-through rate, and average position for each query. This data is authoritative because it comes from Google directly, not from a crawl or panel-based estimate.

For keyword research, Search Console's value lies in two areas. First, it surfaces keywords you already rank for that you did not deliberately target, which identifies opportunities to create or improve content around those terms. Second, it shows keywords where you rank between positions 8 and 20 with low click-through rates, which are prime candidates for content improvement that can lift rankings and traffic simultaneously.

Connecting Search Console data to your content planning is the foundation of a free keyword strategy. If you are not already using it for this purpose, it is the first tool to add. The free SEO tools guide covers how Search Console fits alongside other free tools in a complete workflow.

Google Trends

Google Trends does not provide absolute search volumes, but it does something no other free tool does: it shows how search interest in a keyword changes over time and varies by geography. For content planning, Trends answers questions that volume data alone cannot. Is this keyword growing or declining? Is there a seasonal peak worth publishing ahead of? Do different regions use different search phrases for the same topic?

Trends also has a comparison function that lets you evaluate multiple keywords simultaneously. When you are choosing between two closely related keyword targets, comparing their relative search interest over time shows which is more stable, which is growing, and which has seasonal patterns that might affect your publishing timing. All of this is free, requires no account, and produces data that paid tools do not replicate.

Google Keyword Planner

Google Keyword Planner is a Google Ads tool that is technically free to access but designed for paid search advertisers. It provides search volume ranges and cost-per-click data for any keyword. The ranges are deliberately broad for accounts without active ad spend, which limits its precision for SEO purposes. For an approximation of keyword volume when no other tool is available, it works. For precise volume data, the ranges are too wide to inform confident decisions about keyword difficulty and targeting priority.

AI-powered free keyword research

AI tools do not access keyword databases or provide search volume data, but they perform two keyword research tasks extremely well: generating keyword ideas from a seed topic, and mapping the questions an audience asks around a subject. Both tasks are time-consuming to do manually and both are covered by free AI tiers.

ChatGPT for keyword ideation

ChatGPT's free tier handles keyword brainstorming efficiently. Given a seed topic, it generates related phrases, long-tail variations, question-format keywords, and semantic clusters. The output is not validated against search data, so it needs to be cross-checked against Google Search Console, Trends, or a volume tool before targeting. Used as an ideation layer, it significantly expands the starting point for keyword research beyond what a single person brainstorming alone would produce.

ChatGPT is also useful for mapping search intent. Asking it to describe what someone searching for a given phrase is trying to accomplish helps clarify whether a keyword warrants a blog article, a product page, a comparison guide, or a how-to tutorial. Intent mapping informs content format decisions that affect rankings, because Google evaluates whether your content type matches what searchers expect to find.

Claude for keyword clustering and content briefs

Claude by Anthropic handles longer context windows, which makes it useful for organising keyword lists. Paste a list of keyword ideas and ask Claude to group them by search intent, topic cluster, or content type. The output structures your keyword research into a content plan without requiring a paid tool. Claude also drafts content briefs from a keyword and target audience description, which saves time in the planning stage of SEO content production.

What this means for your budget keyword strategy

A free keyword strategy built on Google Search Console, Google Trends, Ahrefs Webmaster Tools, and the Semrush free tier covers the core research needs of most small sites. Search Console reveals what you already rank for and where quick wins exist. Trends validates topic timing and regional relevance. Ahrefs Webmaster Tools provides professional-grade data on your own domain. Semrush's 10 daily lookups handle targeted volume checks before publishing.

Storing and organising keyword research in a free tool completes the workflow. Airtable's free tier handles keyword tracking databases with fields for target keyword, target page, current position, search volume estimate, and priority score. A structured keyword database in Airtable turns scattered research into a prioritised content plan at no cost.

The ceiling of a free keyword strategy is not the tools. It is time. Free research takes longer per keyword than paid platforms where bulk exports and pre-built keyword gap reports accelerate the process. For sites publishing one to four pieces of content per month, the time investment is manageable. As publishing frequency increases, the case for paid keyword tools grows, but the transition is a capacity decision, not a quality one.

Free keyword research tools: quick comparison

Each tool in this guide has a different strength, and understanding which to use for which task saves time during research. Google Search Console is the first tool to check when researching a topic your site already covers; it surfaces existing ranking data that guides whether to create new content or improve existing pages. Ahrefs Webmaster Tools gives you the same depth on your own domain that Ahrefs' paid plans provide for any domain. Semrush's free tier is the most practical for checking individual keyword metrics before committing to a topic. Google Trends is the only tool that shows intent and interest trajectory over time. ChatGPT handles ideation and intent mapping when you need to expand from a seed keyword rapidly.

None of these tools replace each other. They cover different questions in the research process and work best used together in sequence: Trends to validate the topic direction, Search Console to check existing coverage, Semrush or Ahrefs Webmaster Tools to check difficulty and volume, and ChatGPT to map related questions and long-tail variations.

For teams considering when to move from free to paid keyword tools, the primary signal is not the quality of results from free tools but the volume of decisions that require keyword data. If you are making five or more keyword decisions per week and spending significant time on research because of free tier limits, a paid subscription at a starter level typically covers its cost quickly through time saved. Until that point, the free tools described in this guide are sufficient for a well-planned content strategy.