Genuinely useful calculators, generators and SEO & email helpers — all running entirely in your browser. No accounts, no limits, nothing leaves your device.
enter visitors and conversions for each variant to get conversion rates, uplift and statistical significance (p-value).
work out how many visitors per variant you need to detect a given uplift at 95% confidence and 80% power.
enter your cost and selling price to get the profit, margin percentage and markup.
add tax to a net amount or extract it from a gross amount at any rate.
see what Stripe, PayPal or any processor takes from a transaction, and what you actually receive.
enter the original price and discount percentage to get the sale price and how much you save.
enter fixed costs, price and variable cost per unit to find how many units you must sell to break even.
work out the hourly rate you need to hit your income target after expenses and realistic billable hours.
convert an annual salary to an hourly, weekly and monthly rate based on your real working hours.
enter parcel dimensions and weight to find the billable weight carriers actually charge on.
enter original dimensions and a new width to get the height that keeps the same proportions.
find how many people to survey for a given confidence level and margin of error.
enter attendees, hourly cost and duration to see what a meeting really costs in salaried time.
enter ad spend and revenue to get your return on ad spend instantly.
work out your customer acquisition cost, lifetime value and the all-important LTV:CAC ratio.
enter visitors and conversions to get your conversion rate instantly.
enter your customers and average price to get monthly recurring revenue, ARR and a 12-month growth projection.
enter customers at the start and how many you lost to get your churn and retention rate.
enter your promoters, passives and detractors to get your Net Promoter Score instantly.
enter followers, likes and comments to get your social media engagement rate.
write your title and meta description with live length checks and a Google search (SERP) preview.
paste your text to get its Flesch Reading Ease score, grade level and sentence stats.
paste your content to see the most-used words and their frequency, so you can check focus without keyword-stuffing.
score your headline on length, numbers and power words, with tips to make it more clickable.
paste text to count words, characters, sentences, paragraphs and reading time instantly.
test text and background colours against WCAG AA and AAA accessibility standards.
see how your link will look when shared on Facebook, LinkedIn and X, with title, description and image.
see how your post fits the limits for X, LinkedIn, Instagram, Threads, TikTok and Facebook as you type.
turn questions and answers into valid FAQPage JSON-LD you can paste into your page to be eligible for rich results.
turn any title into a clean, SEO-friendly URL slug (lowercase, hyphenated, no special characters).
build a valid robots.txt with allow/disallow rules and your sitemap in seconds.
checks length, word count, emoji, ALL-CAPS and spam-trigger words, with an inbox preview.
paste your email and it flags spam-trigger phrases, ALL-CAPS and excess punctuation that hurt deliverability.
enter a name and company domain to see the most common professional email formats (first.last@, flast@, and more).
fill in your details and copy a clean, professional HTML signature for Gmail, Outlook and more.
create a QR code from any text or URL and download it as PNG or SVG.
create CODE128, EAN-13, UPC and CODE39 barcodes in your browser and download them as PNG or SVG.
create a random, secure password with adjustable length and character sets.
estimates the entropy and rough crack time of a password and tells you how to make it stronger.
create a favicon from a letter or emoji with your own colours and shape, and download it as a PNG.
pick a base colour and get a matching palette with hex codes for your brand, site or ad creative.
pick two colours and an angle, preview the gradient live, and copy the CSS.
shrink JPG and PNG file sizes in your browser with an adjustable quality slider.
fill in your details and line items and download a clean PDF invoice in seconds.
add trackable utm_source, utm_medium and utm_campaign tags to any URL so you can see exactly which campaign drove each visit.
25-minute focus sessions with 5-minute breaks, right in your browser.