How to compare search volumes across tools: align the settings before comparing values and rankings

When comparing search volumes across tools, first check whether they report search volume or relative interest, then use matching keywords, regions, time periods, and search platforms. In practice, you can choose one tool as your primary benchmark and use others for cross-checking. Do not combine figures from different tools into a single ranking or assume they represent exact search counts simply because they come from Google.

First, distinguish between search volume, interest, and suggested terms

Tools can all help with keyword selection, but that does not mean the data they provide is directly comparable. Welly’s 2024 article explains that Google Trends shows relative changes in search interest rather than actual search volume; Semrush’s introduction also describes it as a tool for identifying trends.

• Search volume data: Useful for comparing the scale of keyword demand, but you still need to check the scope of the data.
• Relative interest: Useful for observing rises, falls, and seasonality, but should not be treated as search counts.
• Search suggestions: Useful for collecting related terms; Welly’s 2022 introduction notes that these suggestions do not themselves provide actual search volume.

For example, you can consult Trends to see when interest in holiday-related keywords starts to rise. To compare search volumes for two terms, however, you should look up search volume data separately rather than directly comparing interest scores with monthly search volumes.

Use the same keywords and matching query settings

Before running queries, check that the keywords are identical, the region is either global or the same specific market, the time periods match, and the data covers the same search platform. Tools cover different platforms and offer region and time options, so do not assume their data covers the same scope just because they all call it “search volume.”

In a 2023 article, yesharris compared four keywords using Ubersuggest and Ahrefs. Although the values differed, both tools ranked them in the same order: “Google Analytics,” “SEO,” “數位行銷” (digital marketing), and “關鍵字Ads” (keyword advertising). This example supports looking at relative rankings first, but it does not mean that all keywords will produce consistent results across all time periods.

The article recommends using the same tool throughout a research project. Forum contributor Randall Magwood, meanwhile, says he compares data from Keyword Planner, Ahrefs, and SpyFu when selecting keywords. You can combine these approaches: use one tool’s data for the main comparison table, then use other tools to check for differences. However, Randall Magwood is describing a personal workflow, not an accuracy test.

A data source can be informative without proving accuracy

A 2025 article by 大文西 emphasizes that Keyword Planner’s data comes from Google and strongly endorses its accuracy. By contrast, awoo’s 2016 article describes the data available at the time as an overview of search volume, with no guarantee about its margin of error. The articles were published at different times and do not provide accuracy tests under matching conditions, so they cannot establish which tool is most accurate today.

When figures differ, first record each tool’s query settings and results, then check whether the keyword rankings differ too. If only the values differ, you can still use the shared ranking as a reference. If the rankings differ too, keep those differences visible rather than choosing a more appealing number as the answer.