Free SEO Tools and Web Developer Utilities
These are the tools and calculators I build for my own work and for everyday use. I keep them free for anyone else who finds them useful.
A growing library of free utilities for SEO operators, growth leads, and SaaS founders, built as living proof of utility-led acquisition as a discipline.
Every tool here is engineered to be useful first and discoverable second. No email gates, no upsells. If something here saves you an hour, that’s the deal.
The last group is not SEO at all: web developer and testing utilities, such as QR codes and test card numbers, built to the same standard.
SEO Systems Tools
Why this matters: why the internal link graph is a product decision
04 toolsMeta Title Generator
Writes SEO titles from page-type formulas, measures each in pixels with a desktop and mobile preview, flags the documented reasons Google rewrites titles, and audits a whole list for duplicates and boilerplate.
JSON-LD Schema Validator
Checks every JSON-LD block on a page together: duplicate and near-identical @id values, broken references, plugin conflicts, Google eligibility as it stands today, and a repaired copy.
Topical Map Generator
Turns your own keyword list into hubs, clusters and pillars, maps them to the pages you already have, flags cannibalisation, ranks what to build first and writes the internal link plan.
Internal Link Mapper and Internal PageRank Calculator
Reads a Screaming Frog export and calculates internal PageRank, click depth, true orphans and weak anchors with navigation links set aside, then simulates the links you plan to add.
AI Search Tools
Why this matters: what AI search actually retrieves
02 tools, 01 pausedAI Citability Checker
Scores every passage of a page on seven rules, all shown, for how well it can be quoted in AI answers, shows each passage without its heading, ranks them against your question and applies snippet controls.
Entity Extractor and Entity Gap Checker
Ranks the entities a page names by salience, with the reason for each score, compares them with up to three competitor pages for the entity gap, and builds about and mentions JSON-LD.
AI Citation Tracker
A monitoring plan rather than a monitor: builds the question set, the recording sheet and the method. Querying assistants on a schedule needs a server, and everything here runs in your browser.
Content Systems Tools
Why this matters: measuring organic when attribution breaks
03 toolsSaaS SEO ROI Calculator
Forecasts SaaS SEO return with a lag and an S-curve, recurring revenue and churn, itemised cost, payback, CAC and LTV, a paid search comparison and a sensitivity chart, with every formula shown.
Search Intent Classifier
Classifies a keyword list by weighting every intent modifier, with the reason for each label, a confidence score, the page type to build, Google’s rater category, and groups of keywords that belong on one page.
Content Gap Checker
Compares your draft with two to five pages that rank for your keyword and lists the terms, phrases, sections and questions they share that you are missing, each shown in context.
Positioning Tools
Why this matters: the full-stack marketer
02 toolsFounder Bio Generator
Turns one set of facts into ten founder bios, from an X bio to a press boilerplate, checks every achievement for a number, a name and plain wording, flags co-founder overlap and writes ProfilePage and Person schema.
NewPositioning Canvas and Competitive Positioning Map
Works through the positioning canvas, sorts your claims against competitors’ into uncontested, contested and table stakes, maps the market and drafts your positioning statement.
Growth and Marketing Calculators
Calculators for the numbers growth work runs on, each with its method shown.
14 toolsA/B Test Significance Calculator
Compares a control with up to four variants: p-value and a confidence interval for the lift, a Bayesian chance to win, a traffic split check against the split you planned, and the visitors the test needed.
NewA/B Test Sample Size Calculator
Works out the visitors and whole weeks an A/B test needs, for several variants and uneven splits, and shows the smallest lift you can detect if you only have a set number of weeks.
NewCAC Calculator
Calculates paid, blended and fully loaded customer acquisition cost from one set of inputs, CAC by channel with shared costs allocated, payback and LTV to CAC, and CAC by month with a sales-cycle lag.
NewLTV Calculator
Calculates customer lifetime value four ways, simple, with expansion, capped and discounted, and from your cohort retention curve, for subscriptions and repeat purchases, with LTV to CAC and payback.
NewCAC Payback Period Calculator
Works out how many months a customer takes to repay acquisition cost: simple, adjusted for churn and expansion, and as cash with annual billing, or for the whole company from spend and MRR.
NewMarkup Calculator
Works out price, cost, markup and margin from any two figures and checks the rest agree, prices a list of up to ten items at once, and prices a resold service from wholesale cost, your time and fees.
NewROAS Calculator
Works out break-even ROAS, target ROAS and maximum CPA from what an order really costs, counts repeat orders, and checks up to eight campaigns against those lines with over-reported revenue adjusted.
NewCPM Calculator, with CPC and CPA
Solves CPM, impressions, CPC, CPA, reach and the rest of the ad funnel from whatever you know, flags inputs that contradict each other, and compares buying by impression, click or conversion.
NewConversion Rate Calculator
Works out a conversion rate with a confidence interval and the traffic needed to pin it down, follows a funnel step by step to the biggest drop, and compares channels or segments on one chart.
NewChurn Rate Calculator
Calculates customer churn for any period and converts monthly to annual properly, revenue churn with NRR, GRR and negative churn from MRR movements, and the month-by-month trend with a weighted average.
NewMRR and ARR Calculator
Builds MRR and ARR from your plan mix with monthly, quarterly and annual billing, seats and discounts, breaks the month into new, expansion, contraction and churned MRR, and projects ARR to a target.
NewNet Revenue Retention Calculator
Calculates net revenue retention and GRR from totals, from a customer list with new customers left out and logo retention, or by segment, converts monthly NRR to annual by compounding, and shows the biggest movers.
NewMarketing ROI Calculator
Works out marketing ROI on gross profit next to ROI on revenue, with itemised costs and the share of sales that would have happened anyway, break-even and target revenue, and a channel comparison.
NewEngagement Rate Calculator
Works out a social media engagement rate by reach, impressions, views and followers side by side, and for a pasted list of posts gives the pooled, average and median rate by format.
Campaign Tracking Tools
02 toolsUTM Builder
Builds UTM links one at a time or in bulk and shows the GA4 channel each lands in, from Google’s own rules and source list, then checks links already tagged for case, spaces and misplaced parameters.
NewCampaign Naming Convention Generator
Builds campaign, ad set and ad names from your own fields and codes for every combination you pick, with matching UTMs and their GA4 channel, and checks existing names, splitting them into columns.
Everyday Calculators
Not marketing tools: calculators for everyday sums, such as counting days between dates, turning a salary into an hourly rate or converting units.
03 toolsDays Between Dates Calculator
Counts calendar and working days between two dates, with a clear choice of which dates count, any weekend, US federal or UK bank holidays for each nation, or your own, and adds or subtracts working days.
NewSalary to Hourly Calculator
Converts a salary to an hourly rate, or any pay period to every other, and shows what you earn per hour actually worked after paid time off, unpaid days and extra hours. Compares two jobs.
NewUnit Converter
Type a quantity such as 5 ft 11 in or 72 kg and see every unit of the same kind at once, with exact results marked and US and imperial gallons, pints and tons kept apart. Converts lists to CSV.
Web Developer Utilities
Not SEO tools: everyday utilities for building and testing websites. Why they are here: utility-led acquisition
04 toolsPassword Generator and Password Entropy Calculator
Generates passwords, passphrases and PINs with exact entropy, even under site rules, and checks any password’s ceiling in bits and the patterns that lower it. Nothing leaves the page.
NewKeyboard Tester
Test every key on full-size, TKL, 75% or 60% keyboards in ANSI or ISO, find which key drops out when several are held, flag key chatter, and export a report.
NewTest Credit Card Generator
Generates Luhn-valid test card numbers for eight networks, labelled invalid cases for negative tests, a validator that shows the Luhn working, and 166 Stripe, Adyen, Braintree and PayPal sandbox cards.
NewQR Code Generator
Static QR codes that never expire, from an encoder written for this page: URL, Wi-Fi, contact, email, SMS, location and event, singly or in bulk, with SVG and PNG downloads and nothing uploaded.
Got an idea for a tool?
I build these on a “would I use this every week?” filter. If there’s a repetitive task in your SEO or growth workflow that doesn’t have a good free tool, tell me.