For Google Ads keyword research, I'd start with Keyword Planner and a clear description of what the business sells. Add another tool when you need a different view: competitor ads, customer questions or a wider set of ideas.
Eight subscriptions would be an expensive way to make one spreadsheet :D The tools below cover different jobs, so use the comparison to choose what is missing from your process.
This guide was refreshed in September 2026 against the linked product pages. These are candidates for a shortlist, not a ranking based on a new hands-on test of all eight products.
Compare the eight tools by the job
| Tool | Job I'd use it for | What to check |
|---|---|---|
| Google Keyword Planner | Starting a Google Ads keyword plan | Location, dates and forecast assumptions |
| Semrush | Expanding and organising keyword ideas | Relevant market coverage and plan limits |
| Ahrefs Keywords Explorer | Understanding topics and organic search results | Whether the SEO context helps your paid search decision |
| Backlinko Keyword Tool | A quick initial keyword lookup | How much detail you need beyond the free tool |
| AnswerThePublic | Exploring customer questions and phrasing | Whether the question suggests a useful paid search audience |
| SpyFu | Investigating competitors' paid keywords and ads | Country coverage and the limits of competitor estimates |
| Ubersuggest | Exploring ideas alongside broader SEO research | Useful output for your niche and required exports |
| KWFinder | Researching keyword variations and local markets | Location settings and the meaning of difficulty scores |
The table is an editorial guide to choosing a starting point. Product capabilities are linked below. Check current access and export limits before buying, especially if several people need to use the same account.
1. Google Keyword Planner: start with the account's market
Google Keyword Planner provides keyword ideas, search estimates and planning forecasts within Google Ads. Start by setting the market you serve and entering 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. This makes it a candidate when the starting list is narrow or you are coordinating paid search with a wider content plan.
I'd give it the same seeds as Keyword Planner and inspect what it adds. Does it surface a useful product term, a comparison the sales team hears, or mostly adjacent topics? That is a better trial question than comparing database sizes.
Keep the distinction between organic and paid competition visible in your sheet. An SEO opportunity still needs a separate decision about whether you want to pay for that visit.
3. Ahrefs Keywords Explorer: investigate the search context
Ahrefs Keywords Explorer provides keyword ideas and analysis of organic search results. It is worth considering when you also need to understand the topics and pages already attracting attention in a market.
For PPC planning, I'd use that context to question the intent behind a term. If the search is largely served by explanations and tutorials, inspect 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 uses Semrush data and presents keyword ideas with metrics such as search volume, difficulty and CPC. It offers a starting point when you want to explore a seed before deciding whether a larger research workflow is needed.
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. Because it uses Semrush data, agreement between these two tools is not independent confirmation from two unrelated data sources.
If you need repeatable bulk research, test the required workflow and exports before relying on a lightweight lookup tool.
5. AnswerThePublic: hear the question behind the keyword
AnswerThePublic's research workflow organises keyword ideas into questions and other phrases drawn from autocomplete data. I'd bring it into the process when the starting list sounds like an internal product catalogue and needs more customer language.
Those questions can help with landing-page explanations, objections and early negative-keyword ideas. A question about doing a repair yourself, for example, 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; the useful test is whether your offer answers it and whether that visit has a plausible business value.
6. SpyFu: investigate the competitor angle
SpyFu offers competitor PPC keyword research and ad history. This is a candidate when the job is to find terms and messages competitors appear to be using, rather than expand from your own seed list alone.
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. Use the observation to form a research question, then judge it against your own offer and economics.
7. Ubersuggest: combine ideas with broader SEO research
Ubersuggest includes keyword suggestions, search volume and intent information alongside competitor and content research. It is a candidate when one person is handling both the PPC shortlist and broader website research.
I'd trial it with a specific output in mind: a set of relevant terms grouped around the products or services you can sell. Inspect whether the added suggestions are useful enough to justify another step in the process.
Compare overlapping keywords using matching market settings. Where tools disagree, 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.
I'd 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. They answer a different question from whether a paid click can become a worthwhile customer.
Two useful companions: Google Trends and AI
Google Trends helps compare interest over time and across regions. Its values are normalised relative interest, not monthly search counts. Use it to investigate timing, then return to the account's market and planning data. Google's explanation of Trends data.
An AI assistant can help 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. Browse the keyword research tools directory for the shortlist, or use the free Google Ads toolkit to build the rest of the workflow.
