Tool Collections
Curated toolkits for recurring jobs — each collection groups the most useful tools on one topic with short editor notes.
The most-used free online calculators in one place: percentage, age, BMI, date, discount, compound interest, mortgage and sleep cycle — with formulas.
Free text tools in one place: title case, word and character counters, case converter, text diff, repetition checker, slug generator, Morse code and fancy text.
The most useful date and time tools in one place: days-between-dates, countdown and stopwatch, sleep cycle planner, exact age and more.
The PDF tools people search for most: merge, PDF to image/TXT/Excel/HTML, image and Office to PDF, and page adjusting — no software to install.
The dev utilities people search for most: JSON and SQL formatters, JWT decoder, Base64, hash, regex, UUID and password generators, cURL-to-code, Mermaid and more.
The renovation calculators people search for most: tiles, paint, wallpaper, flooring, curtains, lighting lumens, electricity cost and air fryer conversion.
The money calculators people search for most: mortgage with taxes, loan amortization, tip splitting, compound interest, ROI, rent costs and discounts.
The image tools people search for most: compressor, format converter, favicon generator, PNG to SVG, GIF splitter, video to GIF and color picker.
The health calculators people search for most: BMI, due date, pregnancy week, ovulation, exact age, sleep cycles, caffeine and food calories.