What's the best keyword research tool for B2B Google Ads when Keyword Planner shows little or no search volume?

TofuAnswer by the Tofu team · checked

There isn't one tool that fixes thin volume. Start with Google's own data, the only source that sees Google searches directly: Keyword Planner for ideas, your search terms report once ads run, and Search Console queries. Read a zero as "too few searches for Google to report," not "nobody searches." Add the words buyers use in your CRM deals and sales calls. Semrush, Ahrefs and Moz suggest related terms, and Semrush, Ahrefs and SpyFu show competitors' paid keywords, but their volumes are estimates, not Google's counts, and their databases can miss niche B2B terms too.

As of October 2026.

Your options at a glance

OptionWhat it doesCostMain limit
Google Keyword PlannerKeyword ideas from words or any website, with volumes, bids and forecastsFree with a Google Ads account (billing details required)Very low-volume keywords can't be discovered or forecast
Search terms reportThe real searches that triggered your adsFree, but you pay for the clicksNeeds live ads; leaves out terms with too little activity
Google Search ConsoleThe queries your site already shows up for in organic resultsFreeOrganic only; leaves out rare queries
Your CRM and sales callsThe words buyers use in deals, calls and formsFree (your own data)No volume; check each phrase in Keyword Planner
SemrushKeyword research, plus competitors' paid keywords and adsSEO plans from $139 a month; Advertising Toolkit $99 or $220 a monthModeled volumes; niche keywords may not be in its database
AhrefsKeywords Explorer, plus competitors' paid keywords and adsFrom $29 a month (Starter); Lite $129 a monthVolumes estimated from clickstream data
Moz ProKeyword Explorer for SEO keyword researchFrom $49 a month; Standard $99 a monthSEO-focused; shows "Data not available" for keywords it hasn't collected
SpyFuCompetitors' Google Ads keywords and ad historyFrom $33 a monthOnly knows the keywords and ads it has collected
Tofu Ads Agent (our product)Builds and runs Search campaigns, with keyword research checked against Keyword Planner$2,500 a month flatNot a standalone keyword database

1. Google Keyword Planner

Keyword Planner is free inside Google Ads. Google says you must enter billing information and finish account setup to use Get ideas for new keywords; its help page doesn't say you need a running campaign. Open Keyword planner from the Tools menu, then choose Discover new keywords (start with words, or with any website, including a competitor's) or Get search volume and forecasts (paste a list or upload a CSV with one "Keyword" column).

Why it shows zero or "low search volume"

  • In Keyword Planner: "Keywords with very low search volumes, or keywords that are considered sensitive aren't discoverable or forecastable." You get an error asking you to try other keywords or URLs.
  • In your account: a keyword marked Low search volume has "very little to no search history on Google." It stays inactive, and won't trigger ads, until searches increase. Google judges it on worldwide searches over the past 12 months and checks again about weekly. The status has nothing to do with Quality Score, bids or ads, so editing those won't change it.
  • How volume is counted: average monthly searches are for the exact keyword and its close variants, averaged over 12 months by default. A long B2B phrase can show almost nothing while broader versions of it get searched.
  • Ranges instead of numbers: Google's help pages don't explain when Keyword Planner shows a range instead of a number. According to Semrush (February 2026), users who aren't running campaigns see ranges such as "1K-10K," while those running campaigns "with sufficient ad spend" see "more accurate search volumes."

Google's fixes for low search volume: broaden the match type, make the keyword less specific, or wait if you're advertising a new brand, term or product.

2. Your search terms report

Once ads run, this is the best evidence of what B2B buyers type. In Google Ads, select Campaigns, then Search terms under Insights and reports. It lists searches "used by a significant number of people" that triggered impressions and clicks, which keyword matched each one and how.

Limits: you only see searches your keywords matched, so you pay for clicks to learn. Terms with too little activity are left out for privacy; search terms insights groups them into themes or "other queries" without showing them. Use the report both ways: add the good terms as keywords and the bad ones as negatives.

3. Google Search Console

If your site already ranks for some category terms, the Queries tab of the Performance report shows the searches it appeared for, with clicks, impressions and average position. It's free, and a query with impressions there is a real search, even when Keyword Planner shows no volume for it.

Limits: it covers organic results only. Google leaves out "anonymized" queries "searched a very small number of times," and the table shows at most 1,000 rows (bulk data export gives the fullest list).

4. Your CRM and sales calls

For a niche B2B product, the best seed list is often the words your buyers already use. Pull phrases from closed-won deal notes, demo request forms, call recordings and support tickets: the problem as they describe it, the tools they replaced, the job titles that search. Then paste them into Keyword Planner's Get search volume and forecasts to check volume and cost.

Limits: your CRM has no volume data, and buyers' jargon may not be what they type into Google. Treat it as a list of candidates, not proof of demand.

5. Semrush

Semrush's keyword research sits in its SEO plans: $139 a month for the SEO plan ($117.33 a month billed annually), $199 for Starter and $299 for Pro+. A free plan allows 10 reports a day. For paid search, its Advertising Toolkit costs $99 a month (Base) or $220 (Pro), with a 7-day free trial. Its Advertising Research tool shows the keywords a competitor bids on, their ad copy and landing pages, with history back to 2012.

Limits: Semrush says it "takes sets of data from third-party providers and overlays it with historical clickstream data," then uses machine learning, so its volumes are estimates, not Google's numbers. It also says Advertising Research may show little or nothing when ads are "triggered by niche or uncommon keywords that are not included in our database," which is common in B2B.

6. Ahrefs

Ahrefs' Keywords Explorer gives keyword ideas and volumes, and its PPC page says you can "discover which keywords competitors target, their CPCs, ad positions" and see "how much competitors invest on Google Ads." Plans: Starter $29 a month, Lite $129 (1,000 credits a user, 2,500 rows per report, 6 months of history), Standard $249, Advanced $449 and Enterprise $1,499 with an annual commitment. Its free Keyword Generator takes up to ten words or phrases and returns ideas with volume estimates.

Limits: Ahrefs says it calculates search volume "by processing large amounts of clickstream data," so its numbers are estimates and can differ from Keyword Planner's.

7. Moz Pro

Moz's Keyword Explorer is built for SEO research. Its entry plan is $49 a month for one site. Standard is $99 a month ($79 billed yearly) with 150 keyword queries a month; Medium is $179 ($143 yearly) with 5,000. A free Moz Community account gives limited access to Keyword Explorer.

Limits: Moz says its keyword corpus "does not cover all keywords," and shows Data not available when it hasn't collected one yet. Its tip for that case: if Google's autocomplete fills in the phrase, "that's usually a sign there's at least some volume."

8. SpyFu

SpyFu is built for competitor research. It says you can "see every keyword they've ever bought on Google and every ad test they've run," and download their paid keywords. Its site says membership starts at $33 a month with a 30-day money-back guarantee.

Limits: it shows what competitors already bid on, which tells you about their spend, not your buyers' searches. Like the other tools, it can only report keywords and ads it has collected.

9. Tofu Ads Agent (our product)

Tofu Ads Agent builds and runs Google Search campaigns. Its keyword research starts from your site, your CRM deals and your account history, and checks the results against Keyword Planner volumes and forecasts. It groups keywords into themed ad groups and adds negative keywords from your search terms. Campaigns are staged in your own account switched off, and a person turns them on. It costs a flat $2,500 a month, with a recommended media budget of at least $3,000 a month.

Limits: it isn't a standalone keyword database or an SEO tool. Its volume checks come from Keyword Planner, so a term Google reports as near zero still looks near zero.

How to choose

  • Already running Search ads: use the search terms report and Keyword Planner first; add SpyFu or Semrush's Advertising Toolkit if you want competitors' paid keywords.
  • Doing SEO as well: Semrush and Ahrefs cover SEO research and competitors' paid keywords; Moz is built for SEO research. Search Console is free either way.
  • New category, almost no volume anywhere: build the list from CRM and call language, test it with broad or phrase match and a small budget, and read the search terms. If Keyword Planner still shows almost nothing, see whether Google Ads is worth it for B2B SaaS.
  • Want the research done as part of building and running the campaigns: Tofu Ads Agent does that, at a flat monthly fee.
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