52 tools · 12 categories · 0 uploads
Free online tools that finish the job before a loading spinner would.
ToolzKit is a workbench of 52 focused utilities — format JSON, decode Base64, compare text, pick colours, generate passwords, convert timestamps. Each one runs entirely inside your browser, so whatever you paste stays with you.
Tip: press / anywhere to open the command palette.
Most used
The tools people open again and again.
Base64 Encoder
Encode text to Base64 with Unicode support, URL-safe alphabet and line-wrap options.
Case Converter
Convert text between lower, upper, title, camel, snake, kebab and more casing styles.
CSV to JSON Converter
Convert CSV data to JSON with proper quote handling, delimiter choice and type inference.
HEX / RGB / HSL Converter
Convert between hex, RGB, HSL and CSS named colours, with contrast ratios against black and white.
JSON Formatter & Validator
Pretty-print, validate and re-indent JSON with precise error messages.
Password Generator
Generate strong, random passwords locally with configurable character sets and entropy estimates.
Percentage Calculator
Calculate percentages, percentage-of, percentage change, and add/subtract percentages.
QR Code Generator
Create customizable QR codes from text or URLs locally, with PNG and SVG downloads.
Browse by category
Twelve groups, each with its own page and a short explanation of when to reach for it.
Developer
9Format, validate and inspect code and data
Web & URL
4Take apart and build up web addresses
Text
7Count, clean, compare and reshape writing
Data & Conversion
4Move between JSON, CSV, YAML and number bases
Encoding
6Base64, URL escaping and HTML entities
Security
5Hashes, tokens and strong passwords
Generators
3Produce identifiers, placeholders and codes
SEO & Webmaster
2Tags, slugs and campaign tracking
Calculators
3Percentages, units and everyday maths
Color & Design
4Convert colors and build CSS effects
Time & Date
3Timestamps, durations and time zones
Productivity
2Everyday desk utilities
Why these tools work differently
Nothing leaves your tab
Every tool is plain JavaScript running on your device. Open your browser's network panel while you work — your input never appears in a request.
No account, ever
There is no sign-up form, no email wall and no usage quota. Bookmark a tool and it works the same on your first visit and your thousandth.
Built to be fast
Pages are small and static. Results update as you type rather than after a round trip to a server, so a paste-and-fix takes seconds.
Guides worth reading
All guidesHow to format JSON correctly
Indentation, key order, trailing commas and the parser errors that catch everyone out.
What is Base64 encoding?
Why binary data gets turned into text, how the 33% size increase happens, and what Base64 is not.
URL encoding explained
Percent-encoding, reserved characters, and the difference between encodeURI and encodeURIComponent.