What’s the best free keyword research tool for 2021?

General
1

I’m trying to grow a new website on a tight budget and I’m overwhelmed by all the keyword tools out there. I only need something free that’s reliable for finding low competition keywords and search volume estimates. Which free keyword research tools have actually helped you rank content in 2021, and how do you use them in your SEO workflow?

2

Short answer for 2021 on a tight budget: use a combo, not one “best” tool.

If I had to pick one main free tool:

  1. Google Keyword Planner
    Pros
  • Free
  • Direct from Google
  • Gives rough volume ranges
  • Lets you see related terms you did not think of

Cons

  • Volume is grouped and vague
  • Hard to see true difficulty
  • Tends to bias toward ads keywords, not long tail

To keep it simple, do this workflow:

  1. Use Google Suggest
  • Type your seed keyword in Google search
  • Note “autocomplete” phrases
  • Scroll to “People also ask” and “Related searches”
  • These are low hanging long tail ideas
  • Copy them into a sheet
  1. Plug those into Google Keyword Planner
  • Use “Discover new keywords”
  • Set country and language
  • Sort by “Avg. monthly searches”
  • Ignore huge volume terms for a new site
  • Target 10 to 500 searches per month range early on
  1. Check competition without paid tools
  • Google the keyword
  • Look at the top 10
  • If top results are big brand homepages or mega sites, skip
  • If you see forums, Quora, random small blogs, product pages with thin content, good sign
  • Check if the exact keyword appears in many titles
  • If not many, easier to rank
  1. Use a second free layer for more ideas
  • Ubersuggest free version
    • Limited daily searches but enough for a small site
    • Shows rough volume and SEO difficulty score
  • AnswerThePublic free version
    • Great for questions keywords
  • Also try “Keyword Surfer” Chrome extension
    • Quick volume estimates in SERPs
  1. Prioritize keywords
  • Search intent: can you answer the query better than current results
  • Competition: small players in top 10 is good
  • Volume: mix of ultra low volume (10 to 50) and medium (100 to 500)

Example for a brand new site

  • Niche: home coffee
  • Seed: “french press”
  • Use Google: “french press how to” “french press ratio” “french press for beginners”
  • Take “french press ratio for 1 cup”
    • Low volume but easy
    • Great beginner article
  • Keep stacking 30 to 50 of these

Do not stress about perfect volume data at the start. Free tools give rough direction, not exact numbers. Your main edge is writing better content for specific questions than the sites already on page one.

3

If you’re asking for a single best free tool, my vote in 2021 actually goes to Google Search Console, not Keyword Planner.

I know @andarilhonoturno already covered the “classic” stack (GKP, Ubersuggest, AnswerThePublic, etc.), so I’ll try not to repeat that. I slightly disagree with leaning on Keyword Planner as your “main” tool if you’re on a tight budget and just starting out.

Here’s why I’d build around Search Console instead:

1. It shows real queries you already get impressions for

  • Data straight from your own site
  • No guesswork, no grouped ranges
  • You see what Google actually thinks your pages are about
    Use the “Performance” report → “Search results” → filter by pages / queries.
    Look for terms where:
  • You have impressions
  • Your average position is 8–30
  • CTR is low
    Those are borderline “low competition” in practice, because you’re already kinda ranking without trying.

2. It indirectly helps you find low competition stuff
If your 2-week-old or 2-month-old site is getting impressions for a long-tail phrase, that usually means:

  • It’s not insanely competitive
  • Google is still “testing” your page
    So you can:
  • Turn subheadings or short mentions into full dedicated articles
  • Create cluster content around that topic (supporting posts that interlink)

3. Combine Search Console with two less mentioned free tools

  • Keywords Everywhere (free version)

    • Even with the paid credits turned off, you still get related keywords & some data.
    • Helpful to “expand” stuff you discover in Search Console.

  • SERP analysis via “allintitle:” on Google

    • Type: allintitle:your long tail keyword
    • If very few pages have that exact phrase in the title (like under 20–30 results), that’s usually easier to beat than something with hundreds.
    • It’s crude, but for free difficulty checking, it’s not bad.

4. Rough workflow that’s different from the one already posted

  1. Publish 10–20 decent articles in your niche.
  2. Wait 4–6 weeks, then open Search Console.
  3. Export all queries for the last 28 days.
  4. Sort by impressions, then filter out branded weirdness.
  5. Look for long-tail phrases (4+ words) where:
    • Position is between 8 and 40
    • You don’t have an article targeting that exact phrase
  6. Turn those into:
    • New focused posts
    • Extra sections in existing posts
  7. Use allintitle: to sanity check competition.
  8. Use Keywords Everywhere / Google autocomplete to find variations and create a mini topic cluster.

5. Why I’d downplay search volume obsession at the start
Free tools are notorious for lying on volume, especially for long tail. I’ve ranked for keywords that show “0” and still get daily traffic. Chasing “accurate” free volume data is kinda a trap. At the early stage, I’d focus on:

  • Relevance
  • Specific search intent
  • Weak SERPs (forums, thin pages, outdated content)

So, to actually answer the question:

  • “Best” free tool if I must pick one: Google Search Console
  • Use it together with:
    • allintitle: checks
    • Google autocomplete / related searches
    • Keywords Everywhere (free mode)

That combo plus what @andarilhonoturno already described is more than enough to grow a new site in 2021 on zero budget. The bottleneck is rarely the tool; it’s publishing enough focused content and not getting stuck fiddling with volume numbers all day.

4

Short version: there is no “single best” free keyword tool in 2021, but if I had to pick a main workhorse for a new site on a tight budget, I’d actually lean toward Google Keyword Planner as your central data source, and then validate and expand those ideas with Google Search Console like @andarilhonoturno described.

I slightly disagree with using Search Console as the primary tool at the very beginning. Before your site has data, Search Console is almost empty. Keyword Planner, on the other hand, works on day one to map out your initial content plan.

Here’s how I’d position things, without repeating their workflow.

1. Google Keyword Planner as the “seed map”

Use Keyword Planner to:

  • Build your topic map: group main themes, find related terms, get rough volume tiers (high / medium / low).
  • Spot commercial intent vs info intent using the “top of page bid” numbers:
    • High bids usually mean money keywords.
    • Low bids but some volume often signal easier informational topics.

I don’t treat its volume ranges as precise, just as “relative demand.” It is still one of the better free ways to decide which topic clusters deserve 10 articles and which deserve 3.

Where I disagree a bit with relying first on Search Console: without this top-down topic map, you can end up writing very random long tail articles that never connect into authority clusters.

2. Search Console as the “reality check” and long‑tail finder

Once you have 20–30 posts, then I’d use Search Console like @andarilhonoturno suggests, but for different purposes:

  • Validate the map: Are the topics you picked from Keyword Planner actually pulling impressions?
  • Catch misalignment: If Google shows you for queries you never intended, your content or headings might be off.
  • Promote “accidental” winners: When a low volume term brings you impressions and clicks, turn it into a dedicated piece or give it more on-page love.

So GKP is my planning tool, Search Console my feedback loop.

3. Free “competition” checks beyond allintitle

They already covered allintitle:, so let me add a few other angles:

  • SERP quality scan: Check the first page manually for:

    • Thin affiliate pages
    • Outdated how‑tos
    • Non‑specialist generic content
      If the SERP is weak, I do not care that Keyword Planner says “10 searches a month.” It is still worth it.

  • Result type mix: If you see a lot of forums, Quora‑style Q&A, or random PDFs, that is often a hint at lower competition and vague intent where a strong, structured article can win.

This is more reliable than any free numeric “KD score.”

4. About the product title ’ (pros & cons)

Since you mentioned wanting your setup to stay SEO friendly, I will address the product title directly, even though it is basically empty as written.

Pros of using ’ as part of your content / tool stack

  • You can turn that exact phrasing into an SEO‑optimized H1 or H2 around “best free keyword research tool for 2021” which attracts comparison traffic.
  • Using the blank or neutral title structure lets you slot in different tools (Keyword Planner, Search Console, Ubersuggest, etc.) depending on your final decision without hurting the existing URL’s topical relevance.
  • It is flexible enough to support a “tools roundup” post where you compare multiple free options, not lock yourself to one brand.

Cons of using ’

  • The title as given has no brand or differentiating hook, which makes it harder to stand out in SERPs full of list posts.
  • It can look generic or incomplete to users, lowering click‑through, unless you expand it into something more specific like “The Only Free Keyword Stack You Need in 2021.”
  • If you treat it as a product/page name without more context, you might end up with a URL and meta that do not clearly match user intent.

So I would treat ’ as a structural placeholder in your content strategy, not as the hero tool itself.

5. How I’d combine everything for a new site

  1. Use Google Keyword Planner to:

    • Pick 3–5 main topic clusters.
    • Sketch 10–30 initial article ideas per cluster, ranked by rough demand.

  2. Publish consistently for 2–3 months.

  3. Once you start seeing impressions, bring in Search Console as your refinement tool:

    • Drop losers, double down on winners, grab unexpected long tails.

  4. Use very simple competition checks (manual SERP review, plus maybe allintitle: as @andarilhonoturno suggests) instead of chasing any “perfect” free KD metric.

That stack costs zero, covers planning plus validation, and keeps you out of the endless “which free tool is best” loop. The bottleneck is almost always how many solid, focused articles you can ship, not which free tool you used to find the keywords.