How to Rank With Calculators, Converters, and Generators

Some of the highest-traffic pages on the internet aren’t articles. They’re tools. A grade calculator. A file converter. A colour-palette generator. An email outreach template. Each one answers a search that a blog post never could, because the searcher doesn’t want to read, they want to do.

That’s the free-tools SEO strategy: instead of writing another guide, you build a small, genuinely useful tool, put it on a page, and let it rank for a query that has huge demand and almost no good competition. Done right, one tool can rank for hundreds of keywords and keep earning traffic for years.

We know this works because we do it ourselves. Our /writing-tools/ subfolder launched from scratch in mid-2023, climbed to nearly a million US organic visits a month at its peak, and now holds steady in the hundreds of thousands, all from free tools built to answer specific searches. Our free SEO tools (keyword generator, backlink checker, traffic checker) tell the same story: they’re consistently among our highest-traffic pages.

Estimated US organic traffic to our /writing-tools/ subfolder (Ahrefs Site Explorer).

There’s a second reason to care about this right now: tools are unusually resilient to AI.

Informational written content is exactly what AI Overviews, AI Mode, and ChatGPT are best at synthesising, and a good chunk of the traffic that used to land on how-to articles is now being answered inside the AI response instead. A tool is much harder to summarise out of existence. AI Overviews can describe how to convert a file or calculate a margin, but it can’t hand the user the working converter or the interactive calculator.

The catch used to be that building tools was expensive. It isn’t anymore. With Letaido or ChatGPT you can spin up a working calculator, converter, or generator in an afternoon, so the bottleneck is no longer engineering, it’s knowing which tool to build. That’s where Ahrefs comes in.

This window may not stay open forever: as tools get trivially easy for everyone to build, the edge will narrow. But for now there’s a real opportunity to build durable search traffic with high-quality free tools made with AI.

Build your own free tools strategy with Ahrefs and Letaido

We’ve built tons of unique features to help you generate organic traffic with free tools:

1. Matching Terms report – pulls every real search variation of a seed pattern (e.g. “calculator,” “generator,” “converter,” “template”)
2. Keyword Difficulty (KD) filter – set to ≤30, paired with lowest Domain Rating (DR) in the SERP, to exclude terms dominated by high-authority sites and surface realistically rankable ones
3. Category filter – narrows Matching Terms results to a specific pattern type, so you’re not sifting through irrelevant variations
4. SERP Overview + Page Types column – shows what’s actually ranking, so you can quickly spot when page one is thin tool pages (winnable) vs. long-form articles (not a tool opportunity)

And now, you can use Letaido by Ahrefs to build and deploy any free tool from a plain-language prompt, generating a working, self-contained page in one pass without needing a developer.

A calculator is a tool that takes a few inputs and returns a number the searcher needs. Someone types “margin calculator”, enters their cost and sale price, and gets their profit margin instantly, no article required.

Omni Calculator shows how far this strategy can go. It’s not a media brand or a SaaS with a big content team, it’s a library of thousands of single-purpose calculators, each one a page targeting a specific “calculator” search. Grade calculators, finance calculators, health calculators, unit conversions. Each page does one job, and together they pull in millions of US visits a month from search.

Omni Calculator’s estimated US organic traffic (Ahrefs Site Explorer).

You don’t have to be a pure-play calculator site to use this.

Gusto is payroll and HR software for small businesses, not a calculator site, but its free hourly paycheck calculator pulls around 17,800 US visits a month, and its salary version another 8,000. Every one of those visitors is a small-business owner working out what to pay someone, which is exactly who Gusto wants running payroll through its product. The calculator answers the question for free, and the software is the obvious next step.

gusto.com/resources/calculators/payroll/hourly-paycheck-calculator estimated US organic traffic (Ahrefs Site Explorer).

And it works at the top end too. Shopify runs a whole /tools/ hub of free calculators and generators as one channel among many. Its profit-margin calculator peaked above 20,000 US visits a month and still pulls a few thousand today, every one of them a merchant weighing up their pricing, which is exactly who Shopify wants selling on its platform. Even a page past its peak keeps introducing the product to the right people for free.

shopify.com/tools/profit-margin-calculator estimated US organic traffic (Ahrefs Site Explorer).

Calculator keyword opportunities

The obvious head terms have huge search volume, but their Keyword Difficulty is 80+ and the results are owned by big brands. You probably won’t rank for these (at least not right away):

The winnable keywords are the niche ones. Search volume is lower, but so is difficulty (often single digits), and Traffic Potential stays high. Find the opportunity closest to your niche, then check whether the equivalent keyword exists for your own audience:

To find your own, paste these seed patterns into Keywords Explorer (Matching terms) and swap the bracketed part for your niche: [thing] calculator, [thing] cost calculator, [thing] price calculator, how much [thing], how many [thing], [thing] estimator, [thing] size calculator, [metric] to [metric], [thing] per [unit], [thing] savings calculator.

A converter changes something from one format into another. Someone searches “mp4 to mp3”, uploads a video file, and downloads the audio; the tool does the one job they came for.

FreeConvert went from around 380K to over 1.5M US organic visits a month in five years on the back of “convert X to Y” searches: video, image, and document converters plus compressors. Every format pair is its own landing page, and there’s no shortage of demand because people convert files constantly and rarely remember which tool they used last.

FreeConvert’s estimated US organic traffic (Ahrefs Site Explorer).

You don’t need to be a converter site either.

Clockify is time-tracking software, but its free military-time converter pulls around 31,200 US visits a month, and its decimal-hours converter another 2,400. Both are the same idea applied to Clockify’s own world: the people converting time formats are the people who might track time in its app. The converter does the one job the searcher came for, and the product sits right there when they’re done.

clockify.me/military-time-converter estimated US organic traffic (Ahrefs Site Explorer).

Adobe sells Acrobat Pro, but its free online converters are a giant top-of-funnel tactic: the PDF-to-Word page alone pulls around 385,000 US visits a month. Each free conversion nudges the user a little closer to the paid subscription.

adobe.com/acrobat/online/pdf-to-word.html estimated US organic traffic (Ahrefs Site Explorer).

Converter keyword opportunities

The common format pairs have big volume, but they’re taken by billion-visit sites like FreeConvert at KD 80+:

The more winnable keywords are the format pairs specific to one profession, where difficulty drops to single digits:

To find your own, paste these seed patterns into Keywords Explorer (Matching terms) and swap the bracketed part for your niche: [niche format] to [niche format], convert [format] to [format], [pro file] to csv, [pro file] to excel, [format] to pdf, [format] to text, [format] to image, [proprietary format] converter, [format] converter online, batch [format] converter.

A generator creates something new from a click or a prompt. Someone searches “color palette generator”, hits the button, and gets a ready-to-use set of colours they can copy or export.

Coolors is a colour-palette generator that grew into a whole suite of design generators: palettes, fonts, gradients, contrast checkers. It nearly doubled its US organic traffic over five years by ranking #1 for “color palette generator”, then adding a page for each adjacent “generator” and “maker” query it could serve.

Coolors’ estimated US organic traffic (Ahrefs Site Explorer).

Kapwing is a video-editing tool, but a lot of its search traffic comes from small free generators: its meme maker pulls around 10,500 US visits a month and its subtitle generator another 5,800. None of those pages sell the editor directly, but the people making memes and subtitles are the people who edit video, so each free generator is a cheap way to put the product in front of the right audience.

kapwing.com/meme-maker estimated US organic traffic (Ahrefs Site Explorer). Traffic can wane, but a fading tool page still pulls far more than zero.

HubSpot does the same at scale. It sells CRM and marketing software, yet one of its best-performing pages is a free email signature generator pulling around 55,000 US visits a month. On the surface, it has nothing to do with the core product, but the people who need an email signature are marketers and salespeople, exactly who HubSpot wants in its funnel. A generator is a cheap, evergreen front door.

hubspot.com/email-signature-generator estimated US organic traffic (Ahrefs Site Explorer).

Generator keyword opportunities

The head terms have big volume but high difficulty:

The winnable keywords are the niche ones: smaller volume, low difficulty, strong Traffic Potential. Find the row closest to your niche, then check whether the equivalent exists for your own audience: