Free SEO & Marketing Tools
A growing set of free, no-signup utilities for SEO, content, AI search, social and paid media — built by our team, for marketers and site owners. Sixteen are live, including eight calculators.
Live tools
01 Schema Markup Generator
Build valid JSON-LD structured data in seconds — Organization, LocalBusiness, Article, Product, FAQ, Breadcrumb and more. Fill a form, copy the code. Open the schema generator →
02 SERP Snippet Preview
See exactly how your title and meta description render in Google — with live desktop and mobile preview and pixel-width and character checks so nothing gets truncated. Open the SERP preview →
03 AI Search Readiness Checker
Score any page for AI search — paste your HTML and it checks schema, FAQ, answer-first structure and entity signals, then gives a fix for every gap. Open the AI readiness checker →
04 ROAS Calculator
Return on ad spend, ACoS and gross profit — plus the break-even ROAS your margin actually needs. Most calculators skip that, which is how a 4x ROAS on a thin margin gets mistaken for a win. Open the ROAS calculator →
05 CPM Calculator
Solves in all three directions — CPM from spend and impressions, the spend a target CPM implies, or the impressions a budget will buy. Add your CTR and it shows what you are really paying per click. Open the CPM calculator →
06 CTR Calculator
Click-through rate from impressions and clicks — then compare two ads and get a statistical significance test, so you stop calling a winner on 40 clicks. Nothing else free does that. Open the CTR calculator →
07 Robots.txt Generator
Build a valid robots.txt from checkboxes — block admin paths, cart pages and internal search, declare your sitemap, and get a hard warning before you accidentally block your whole site. Open the robots.txt generator →
08 UTM Campaign URL Builder
Clean, consistent UTM-tagged links — with a check for medium values GA4's channel grouping won't recognise, plus a running history so a mid-session refresh doesn't cost you your links. Open the UTM builder →
09 Keyword Density Checker
Word count, keyword frequency and the most-repeated phrases in your text — instantly, in your browser. Includes what Google actually says about "ideal" density (there isn't one). Open the keyword density checker →
10 CAC Calculator
Customer acquisition cost — plus the LTV:CAC ratio and payback period most free CAC calculators skip. A raw CAC number alone tells you nothing. Open the CAC calculator →
11 Ad Budget Calculator
Set a revenue goal and work backwards through your real funnel — deal value, close rate, conversion rate, CPC — to the budget it implies. Not a generic "% of revenue" guess. Open the ad budget calculator →
12 CPC Calculator
Cost per click — plus solve backwards from a budget or a click goal, so you can plan spend before it happens, not just measure it after. Open the CPC calculator →
13 Conversion Rate Calculator
Conversion rate, or work backwards to the visitors or conversions you need — plus a statistical significance test for comparing two variants, so you stop calling an A/B winner on a handful of conversions. Open the conversion rate calculator →
14 URL Slug Generator
Paste a whole list of page titles and get clean slugs for all of them at once — accents, emoji and stop words stripped, character count flagged, full URL previewed. Most slug tools do one title at a time. Open the slug generator →
15 Content Readability Checker
Flesch score, grade level, word and character count and reading time — plus every sentence over 25 words highlighted in a preview pane, so you can see where the problem is instead of just being told there is one. Open the readability checker →
16 Engagement Rate Calculator
Engagement rate by followers, by reach and by impressions — side by side, with each formula shown, for Instagram, LinkedIn, YouTube and X. Because an engagement rate quoted without its denominator means nothing. Open the engagement rate calculator →
Why we build free tools
Good tools do more than fill a page. They solve a real, repeated job — and the best way to show how we think about SEO and paid media is to hand you something useful, not a brochure.
Each tool here maps to a service we run: the schema generator and the AI readiness checker sit alongside our AI-search work, the robots.txt generator, slug generator and keyword density checker alongside technical and content SEO, the readability checker alongside content marketing, the engagement rate calculator alongside social media, and the UTM builder plus the CPM, CTR, CPC, conversion rate, ROAS, CAC and ad budget calculators alongside performance marketing. Use the tool yourself, and if you would rather it was done for you at scale, the matching service is one click away.
The three campaign calculators, and when each one applies
They look similar and they are not. Each answers a different question about the same campaign, in the order the money moves through it.
CPM comes first — it is what you pay to be seen, per thousand impressions. It tells you whether the buy itself was efficient, and it is the number you plan a budget against before a single click happens.
CTR comes second — of the people who saw the ad, what share clicked. That is a verdict on the creative and the targeting, not on the buy. It is also the number most often misread: two ads at 1.8% and 2.4% look decisively different and frequently are not, which is why our calculator runs the significance test instead of leaving you to eyeball it.
ROAS comes last — revenue back per rupee spent, and the only one of the three that speaks to profit. A campaign can have an excellent CPM, a strong CTR, and still lose money. That is why the ROAS calculator asks for your margin and shows the break-even ROAS you actually need, rather than just the number.
If you want the concepts rather than the arithmetic, each metric has a full explainer in the performance marketing guide.
The two budgeting calculators, and how they connect
CPM, CTR and ROAS judge a campaign that's already running. The CAC and ad budget calculators sit one step earlier — planning and sanity-checking the spend itself.
The ad budget calculator works forward — from a revenue goal, through your real funnel rates, to the budget that goal implies. It also hands back the implied cost per lead and implied CAC as a side effect of the same math.
The CAC calculator works from the other end — given what you actually spent and how many customers you actually got, is that acquisition cost sustainable against what a customer is worth? The two are designed to be used together: plan a budget with one, then check the resulting acquisition math with the other once real numbers come in.
The CPC and conversion-rate calculators, and how they extend the paid-media set
CPC and conversion rate are the two links between the campaign calculators above and revenue itself — cost per click on one side of the equation, what a click actually becomes on the other.
The CPC calculator solves in three directions — CPC from spend and clicks, clicks affordable from a budget, or budget required for a click target — the same solve-backwards pattern already proven on the CPM calculator, but for the metric advertisers actually bid on.
The conversion rate calculator picks up where CPC leaves off: once a click lands, did it convert? It solves conversion rate, conversions needed, or visitors needed — and its Compare mode runs the same two-proportion significance test built for the CTR calculator, so a landing-page A/B "winner" gets the same statistical scrutiny an ad-creative winner already does.
The three newest tools, and the jobs they cover
The set above is almost entirely about money moving through a campaign. These three cover jobs that happen earlier or elsewhere — naming a page, editing a draft, and reporting on organic social.
The URL slug generator is the smallest job on the list and the one most often done badly at scale. Free slug tools take one title; this one takes a whole content calendar's worth at once, strips accents, emoji and stop words, flags anything over 75 characters, and previews the full URL. It also carries the slug conventions this site follows, because the rules matter more than the tool: no dates, no stop words, three to five words, lowercase, hyphens, trailing slash. It will not tell you whether that slug already exists on your site — that part is still your job, and changing a live slug without a 301 costs you the rankings the old URL earned.
The readability checker gives you the Flesch numbers everyone quotes, but its useful half is the preview pane: every sentence over 25 words is highlighted where it sits, so an editor can fix the paragraph rather than stare at a score. It bundles a word counter and a character counter in the same page rather than spinning those out as two thin tools. It is also honest about what it is — the Flesch formulas are heuristics built for English prose, they cannot see whether writing is accurate or useful, and they penalise technical vocabulary your reader may understand perfectly well. A low score on a page written for specialists is not automatically a problem.
The engagement rate calculator exists because the same post can honestly be reported at three different engagement rates depending on the denominator — followers, reach, or impressions. It shows all three at once with each formula spelled out using your own numbers, across Instagram, LinkedIn, YouTube and X. What it deliberately does not do is tell you what a good engagement rate is. Published benchmarks disagree with each other wildly, shift with account size, niche and format, and usually never state which denominator they used, which makes them unusable for comparison. The comparisons that actually hold are your own account over time and your own competitors measured the same way — the metric context sits in marketing KPIs that actually matter and the social media marketing guide.
Which one do you need?
| If this is your problem | Use this | Then read |
|---|---|---|
| You are spending on ads and are not sure it is profitable | ROAS Calculator | The performance marketing guide |
| You are planning a media budget, or checking what you actually paid for reach | CPM Calculator | What CPM means |
| Two ads are performing differently and you need to know whether it is real | CTR Calculator | What CTR means |
| You need to know what a click costs, or plan spend around a click goal | CPC Calculator | What CPC means |
| Clicks are landing and you want to know what share convert, or test two variants | Conversion Rate Calculator | What conversion rate means |
| You have a revenue goal and need to know what budget it requires | Ad Budget Calculator | The performance marketing guide |
| You know your spend and customer count and want to know if it's sustainable | CAC Calculator | Customer acquisition cost, explained |
| You are reporting on organic social and need a defensible engagement number | Engagement Rate Calculator | Marketing KPIs that actually matter |
| You need to build or fix your site's crawl rules | Robots.txt Generator | Robots.txt, explained |
| You are launching a campaign and need clean tracking links | UTM Builder | GA4 setup for marketers |
| You are naming new pages and want consistent, clean URLs | URL Slug Generator | Canonical tags, explained |
| A draft reads heavily and you want to know which sentences to cut | Content Readability Checker | Content marketing strategy |
| You want a sanity check that your content isn't accidentally repetitive | Keyword Density Checker | On-page SEO |
| You rank but nobody clicks | SERP Snippet Preview | How to write meta descriptions |
| You want richer results and better AI citation | Schema Markup Generator | What schema markup does |
| You are visible on Google but never in ChatGPT | AI Search Readiness Checker | The AI search guide |
Frequently asked questions
Are these tools really free?
Yes. All sixteen are free to use with no signup, no login and no credit card. They run entirely in your browser, so your inputs stay on your device and nothing is sent to us. We build them to be genuinely useful and to show how we think about SEO, content, AI search, social and paid media.
Do I need to create an account to use them?
No. There is no account, no email gate and no trial. Open the tool, use it, copy your result and leave. We would rather you came back because the tool was good than because we held your result hostage.
Which tool should I start with?
Start with the ad budget calculator if you have a revenue goal and need to know what to spend, or the CAC calculator if you already have spend and customer numbers and want to know if the math holds up. Use the CPC calculator to work out what a click costs, and the conversion rate calculator once clicks are landing and you want to know what share convert — including whether an A/B test winner is statistically real. Use the ROAS calculator if you are spending on ads and want to know whether it is profitable, the CPM calculator when planning or auditing a media buy, and the CTR calculator when comparing two ads. On the organic side: the engagement rate calculator when you are reporting on social, the readability checker when a draft reads heavily, the URL slug generator when naming a batch of new pages, the robots.txt generator or UTM builder for technical campaign setup, the keyword density checker or schema markup generator when polishing content, the SERP snippet preview if your pages rank but nobody clicks, and the AI search readiness checker if you are visible on Google but never in ChatGPT or AI Overviews.
What is the difference between the CAC calculator and the ad budget calculator?
They work in opposite directions on the same problem. The ad budget calculator starts from a revenue goal and works forward through your funnel to a budget number. The CAC calculator starts from spend you've already committed and works out whether the resulting acquisition cost is actually sustainable against what a customer is worth. Plan with one, verify with the other.
What is the difference between the CTR calculator and the conversion rate calculator?
They test the same kind of question at two different stages of the funnel. The CTR calculator's Compare mode tells you whether one ad genuinely out-clicked another, or whether the gap is just small-sample noise. The conversion rate calculator's Compare mode runs the identical statistical test one step later — on landing-page or offer variants, using conversions and visitors instead of clicks and impressions. If you have ever called an A/B test on a handful of results, either tool will tell you whether that call actually holds up.
What is the difference between the readability checker and the keyword density checker?
Both take pasted text, and they answer different questions. The keyword density checker looks at which words repeat — frequency, phrases, and whether a draft is accidentally saying the same thing twenty times. The readability checker looks at how the sentences are built — length, syllables, passive constructions, and the Flesch scores that come out of those. One catches repetition, the other catches heaviness. A draft can easily fail one and pass the other.
Can I use these tools for any website?
Yes. They are not tied to Digital Hangover clients or to any particular platform, and you can use them on any site or ad account you work on, including for your own clients. The schema, SERP, slug, readability and keyword density tools work on any URL, HTML or text you paste in, the calculators work in any currency, and the robots.txt and UTM tools work for any domain.
Will you add more tools?
Yes — the slug generator, readability checker and engagement rate calculator are the latest, live now, and more are in planning. Bookmark this page; every new tool lands here first, and we announce nothing until it actually works.
Tools are the DIY. We do the heavy lifting.
From technical SEO to AI-search visibility to profitable paid media — we run it end to end for 150+ brands.
