The Blog
Guides, tips and how-tos for getting the most out of free online tools.
Pretty-print, validate and fix JSON free online — turn a minified one-liner into readable, indented JSON and catch errors instantly.
Save just one page of a PDF as its own file — free, private, in your browser. The quickest way to pull a single page out of a big document.
Minify CSS, JavaScript and HTML free online to shrink file size and speed up your site — what minification does and when to use it.
Work out a 15%, 18% or 20% tip fast — the mental-math trick and a free tip calculator that also splits the bill between friends.
Convert text between UPPERCASE, lowercase, Title Case and Sentence case free online — fix caps-lock mistakes and format headings fast.
How many working days a month has (usually 20–23), why it changes, and how to count the exact business days in any month, free online.
Remove duplicate lines from any list free online — dedupe emails, keywords or data instantly, and sort or clean the result too.
Convert km/h to mph and back — the exact factor, a quick mental shortcut, common speed limits, and a free speed converter.
Stay under the limit — count characters for a tweet (280), Instagram bio (150) or meta description (~155) live, free, in your browser.
Convert numbers to words free online — write amounts in words for cheques and legal forms, in both international and Indian number systems.
Convert numbers to Roman numerals and back free online — plus the simple rules behind I, V, X, L, C, D and M so you can read any of them.
Convert Unix timestamps to human dates and back free online — what epoch time is, why developers use it, and the year-2038 problem.