For Google Ads keyword research, start with Google Keyword Planner: it is free with a Google Ads account and gives you Google's own search estimates and forecasts for a campaign plan. Add SpyFu or Semrush when the job is seeing which keywords competitors advertise on, AnswerThePublic when you need the questions customers ask in their own words, and Ahrefs, Ubersuggest or KWFinder when you also want to inspect the organic search results around a term. The Backlinko Keyword Tool covers a quick free lookup when you have no ad account to hand.
Eight subscriptions would be an expensive way to make one spreadsheet :D The tools below cover different research jobs, so use the table to find the one view missing from your process, then read the matching section before you trial it.
These are candidates for a shortlist, not a ranking. I checked each vendor's public pricing page on 30 October 2026 and linked it beside the claim. Where a page could not be read, the table says so rather than guessing.
The eight tools compared
| Tool | Pricing model | Free tier | Best for |
|---|---|---|---|
| Google Keyword Planner | Free inside Google Ads | Free; you must complete Google Ads account setup, including billing details, to see keyword ideas | Search volume estimates, keyword ideas and forecasts from Google's own data, the starting point for any Search campaign plan |
| Semrush | Paid subscription with tiered plans | Free plan with one project and ten reports a day; paid plans offer a seven-day trial | Expanding a keyword list, grouping it by topic and seeing competitor advertising alongside organic data |
| Ahrefs | Paid subscription with tiered plans | Limited free keyword generator; Ahrefs Free covers your own site | Understanding the organic results and topics around a term before you bid on it |
| Backlinko Keyword Tool | Free | Free to use, drawing on Semrush's keyword database | A quick first check of volume and related terms without an ad account |
| AnswerThePublic | Paid subscription from a Starter plan | No free plan shown on the pricing page | Finding the questions and phrases customers use around a topic |
| SpyFu | Paid subscription | Not verified; the pricing page could not be read when checked | Seeing a competitor's paid keywords and ad history before writing your own ads |
| Ubersuggest | Paid subscription with three tiers, or lifetime access | Seven-day trial on monthly plans; a free account exists but its limits are not stated | One person handling both a PPC shortlist and broader website research |
| KWFinder | Paid Mangools subscription (Basic, Premium, Agency) | Free account with five lookups every 24 hours | Exploring keyword variations for a specific location with search-result context |
Each row stands on its own, so you can compare two tools without reading the whole table. Check current limits and exports before paying, especially when several people need the same account.
1. Google Keyword Planner: start with the account's market
Google Keyword Planner provides keyword ideas, search estimates and planning forecasts inside Google Ads. Google describes it as a free resource for advertisers, with one condition worth knowing: you need to complete account setup, including billing information, before the basic keyword suggestions appear. Google's access requirements.
Set the market you serve first, then enter a few specific products or services. For a hypothetical boiler repair company, “emergency boiler repair” is a more useful starting conversation than “heating”. One describes a service someone might need now; the other leaves a lot of room for interpretation.
I'd export the relevant ideas, remove obvious mismatches and group the remainder by the landing page that could answer the search. A forecast helps with planning, but the business still needs to decide which enquiries it wants.
2. Semrush: expand a list and organise the themes
Semrush's keyword research tools offer keyword discovery, filters, competitor gaps and topic grouping. That makes it a candidate when the starting list is narrow or you are coordinating paid search with a wider content plan.
The Semrush pricing page lists a free plan with one demo project and ten reports a day, and tiered paid plans with a seven-day trial. The free allowance is enough to find out whether the tool adds anything to your list before you pay for it.
I'd give it the same seeds as Keyword Planner and inspect what it adds. Does it surface a product term, a comparison the sales team hears, or mostly adjacent topics? That is a better trial question than comparing database sizes. Keep organic and paid competition in separate columns; an SEO opportunity still needs its own decision about whether you want to pay for that visit.
3. Ahrefs: investigate the search context
Ahrefs Keywords Explorer provides keyword ideas and analysis of the organic results for a term. It is worth considering when you also need to understand the topics and pages already attracting attention in a market.
Ahrefs pricing is a tiered subscription, with a cheaper Starter tier for search and competitor lookups and an Ahrefs Free plan aimed at your own site. The free keyword generator is limited compared with a paid account, but it answers the vocabulary question for a single seed.
For PPC planning, use that context to question the intent behind a term. If the search is largely served by explanations and tutorials, check whether your offer answers the same need before building an ad group around it. Treat organic keyword difficulty as an SEO metric; it cannot tell you what a qualified lead will cost in your Google Ads account.
4. Backlinko Keyword Tool: make a quick first pass
Backlinko's free Keyword Tool presents keyword ideas with search volume, difficulty and CPC, using data from Semrush's keyword database. Backlinko is a Semrush trademark, so agreement between these two tools is not independent confirmation from two unrelated sources.
I'd use it for a quick check of vocabulary and related terms, then move the useful ideas into the same shortlist as everything else. If you need repeatable bulk research, test the workflow and exports you need before relying on a lightweight lookup tool.
5. AnswerThePublic: hear the question behind the keyword
AnswerThePublic organises keyword ideas into questions and other phrases drawn from autocomplete data. Bring it into the process when the starting list sounds like an internal product catalogue and needs more customer language.
The AnswerThePublic pricing page lists Starter, Growth and Business plans, with Starter aimed at individuals working on a single project. No free plan appears on that page, so budget for at least the Starter tier if you want it in the toolkit.
Those questions help with landing-page explanations, objections and early negative-keyword ideas. A question about doing a repair yourself deserves different treatment from a search for someone to perform the repair. Review the actual phrases before assigning intent; a question-shaped search is not automatically unsuitable for ads.
6. SpyFu: investigate the competitor angle
SpyFu offers competitor PPC keyword research and ad history. It is a candidate when the job is to find the terms and messages competitors appear to be using, rather than expanding from your own seed list alone.
SpyFu sells a paid membership. Its pricing page refused the automated check behind this article, so confirm the current plans and any trial terms on spyfu.com before you rely on it for a large research project.
I'd inspect a few relevant competitors and note the themes worth checking in the account's target market. Keep their brand terms, your service terms and unrelated products separate so the export does not become a ready-to-upload campaign by accident. A competitor appearing against a keyword does not establish that the keyword is profitable for them or suitable for you.
7. Ubersuggest: combine ideas with broader SEO research
Ubersuggest includes keyword suggestions, search volume and intent information alongside competitor and content research. It suits one person handling both the PPC shortlist and broader website research.
The Ubersuggest pricing page shows three tiers, a one-time seven-day free trial for monthly subscriptions and a lifetime purchase option. The page mentions a free account but does not spell out its limits, so expect the trial to be the useful evaluation window.
Trial it with a specific output in mind: a set of relevant terms grouped around the products or services you can sell. Where tools disagree on volume, record the uncertainty instead of choosing whichever estimate makes the campaign plan look bigger.
8. KWFinder: explore variations in the right location
KWFinder from Mangools focuses on keyword research, including local research and keyword difficulty. It belongs on the shortlist when you want to explore variations for a particular market and inspect their search context.
Mangools sells KWFinder as part of its Basic, Premium and Agency plans, and the product page offers a free account with five lookups every 24 hours. That is enough to check whether the location data covers your market before you subscribe.
Test it with a service, a location and a few customer phrases you already recognise, then check whether the results help you separate relevant variations from broad or ambiguous searches. As with the other SEO-oriented tools, keep difficulty scores out of the role of a PPC profitability score.
Two useful companions: Google Trends and AI
Google Trends compares interest over time and across regions. Its values are normalised relative interest, not monthly search counts, so use it to investigate timing and then return to the account's market and planning data. Google's explanation of Trends data.
An AI assistant can brainstorm seed phrases or propose groups from a list you provide. Ask it to explain its grouping and leave demand estimates blank unless you supply a source. Fluent suggestions are still suggestions; inspect them before they enter the plan.
Turn the research into a campaign shortlist
Use one sheet with columns for the search term, intended customer need, landing page, market, data source and your decision. That last column matters: keep, investigate or exclude.
For a hypothetical local repair business, “book boiler repair” could map to a repair page, “boiler repair jobs” to an exclusion candidate, and “boiler repair cost” to a closer look at the offer and landing-page information. The words overlap, but the decisions differ.
Start with Keyword Planner, add one tool that supplies a missing perspective, and review the combined list with the business. The keyword research shortlist walks through four of these tools in that order, and the keyword research tools category lists every option in the directory, including a few free local-keyword generators that did not make this article.
