DevKit Labs
A free collection of developer and everyday utilities — JSON formatter, Base64, JWT, hashing, converters and more. Everything runs in your browser, nothing is uploaded.
Convert
Convert between data formats and units.
CSV ⇄ JSON
Convert CSV to JSON and back, with quoted fields and custom delimiters — 100% in your browser.
JSON to TypeScript
Generate TypeScript interfaces from a JSON sample — nested types and optional fields, 100% in your browser.
Markdown ⇄ HTML
Convert Markdown to HTML and HTML back to Markdown — GitHub-flavored, 100% in your browser.
Number Base Converter
Convert numbers between binary, octal, decimal, hexadecimal and any base 2–36 — 100% in your browser.
Timestamp Converter
Convert between Unix timestamps and human-readable dates — with a live epoch clock, 100% in your browser.
TOML ⇄ JSON
Convert TOML to JSON and back — tables, arrays and typed values, 100% in your browser.
XML ⇄ JSON
Convert XML to JSON and back, with attributes and nested elements — 100% in your browser.
YAML ⇄ JSON
Convert YAML to JSON and back — config-friendly and accurate, 100% in your browser.
Encode / Decode
Base64, URL, JWT and other encodings.
Base64 Encode / Decode
Encode text to Base64 or decode it back — with URL-safe and file support, 100% in your browser.
HTML Entities
Encode text to HTML entities or decode them back — including named and numeric entities, 100% in your browser.
JWT Decoder
Decode and inspect a JSON Web Token's header, payload and claims — and verify HMAC signatures, 100% in your browser.
URL Encode / Decode
Percent-encode or decode URLs and query strings — with a parameter parser, 100% in your browser.
Format & Validate
Beautify, minify and validate code.
Generate
IDs, passwords, QR codes and mock data.
Lorem Ipsum
Generate placeholder text — paragraphs, sentences, words or lists, with optional HTML — 100% in your browser.
Mock Data Generator
Generate realistic fake data from a custom schema as JSON, CSV or SQL — 100% in your browser.
QR Code Generator
Create custom QR codes for URLs, Wi-Fi, contacts and more — download as PNG or SVG, 100% in your browser.
UUID Generator
Generate UUIDs, ULIDs and NanoIDs in bulk — cryptographically secure and 100% in your browser.
Text
Diff, case, counting and regex.
Case Converter
Convert text between camelCase, snake_case, kebab-case, Title Case and 10 more — instantly and privately.
Regex Tester
Test regular expressions with live match highlighting, capture groups and replace — 100% in your browser.
Slug Generator
Turn any title into a clean, URL-friendly slug — accents transliterated, 100% in your browser.
String Inspector
Inspect a string's length, encoding and every character's code point — 100% in your browser.
Text Diff
Compare two blocks of text and highlight the differences line by line — 100% in your browser.
Word Counter
Count words, characters, sentences and reading time as you type — with keyword density, 100% in your browser.
Crypto & Security
Hashing, encryption and passwords.
Web & Network
Color, IP, headers and cron.
Color Converter
Pick a color and convert between HEX, RGB, HSL, HSV and CMYK — with alpha and shades, 100% in your browser.
Cron Builder
Understand any cron expression in plain English and preview its next run times — 100% in your browser.
HTTP Status Codes
Search and browse every HTTP status code with plain-English meanings — 100% in your browser.
IP / CIDR Calculator
Calculate network, broadcast, host range and subnet mask from an IPv4 CIDR — 100% in your browser.