Encoders & Converters
15 free tools · runs in your browser
Base64, URL, hash, binary, JSON/YAML/CSV converters and number-base tools — all running instantly in your browser. Like every tool on UsefulTools, these are free, require no signup, and process everything locally on your device.
Base64 Encoder / Decoder
UTF-8-safe Base64 encode and decode
URL Encoder / Decoder
Percent-encode or decode URLs and params
HTML Entity Encoder / Decoder
Escape or unescape HTML entities safely
Number Base Converter
Binary, octal, decimal, hex and any base 2–36
Binary to Text Converter
Decode 0s and 1s into readable text
Hex to Text Converter
Decode hexadecimal into readable text
Hash Generator
SHA-256, SHA-1, SHA-512, MD5 & CRC32 checksums
JWT Decoder
Inspect JWT header, payload and expiry
Unix Timestamp Converter
Epoch to date and back, in your timezone
Roman Numeral Converter
Numbers to Roman numerals and back
Number to Words Converter
Spell out numbers in English words
JSON Formatter & Validator
Beautify, validate and minify JSON
JSON to YAML Converter
Two-way JSON and YAML conversion
JSON to CSV Converter
Flatten JSON arrays into CSV spreadsheets
CSV to JSON Converter
Spreadsheet rows to clean JSON objects