Free calculators and checkers that explain themselves.

Every tool shows its method, a worked example and answers to common questions. Most run entirely in your browser.

Pay & Work

Pay, raises and what lands in your pocket.

Pay Raise CalculatorSee what a raise is worth per hour, week, month and year. Enter a percent raise or a new pay amount and compare before and after.

Fees, margins and tracking for people who sell.

UTM BuilderAdd UTM source, medium and campaign tags to any web address. Build a clean tracking link in seconds and copy it. Nothing is stored.
eBay Fee CalculatorPick your eBay category and see the final value fee, your profit, margin and break-even price. Uses eBay’s own fee table. Free, private, no sign-up.

Check your connection, addresses and sites.

What Is My IP AddressSee your public IP address in one click, and whether it is IPv4 or IPv6. Optional location and network details. No sign-up.
IP LookupLook up any IPv4 or IPv6 address to see its country, region, city, time zone and network provider. Checks the address format first.

Quick helpers for code, data and AI work.

JSON FormatterPaste JSON to pretty-print, minify or sort it. Get the line and column of any error. Runs in your browser, so your data is never uploaded.
OpenAI TokenizerCount how many tokens your text uses with OpenAI’s GPT tokenizers. See exactly how the text is split. Runs in your browser, nothing is uploaded.

Small jobs you do every week.

Tip CalculatorWork out the tip, the total and each person’s share in one step. Pick a tip percent, set the number of people, and round up if you like.
Word CounterPaste or type text to count words, characters, sentences and paragraphs. See reading time, speaking time and your most used words. Private, in your browser.
QR Code GeneratorTurn a link or text into a QR code you can download as SVG or PNG. Choose the error correction level. Free, no expiry, no sign-up.