Utill.net
Free online utilities for encoding, encryption, formatting, and more.
Encode & Decode
Base64 Encoder & Decoder
Encode UTF-8 text to Base64 or decode Base64 strings back to plain text. Useful for API payloads, Basic Auth debugging, and data snippets.
Unicode Escape Encoder & Decoder
Encode text as \uXXXX, \xXX, or HTML hex entities, and decode escaped strings back to readable text for code, JSON, and config work.
URL Encoder & Decoder — Percent-Encoding
Encode and decode percent-encoded URL text for query strings, path segments, redirects, and API parameters.
JWT Decoder Online — Inspect JSON Web Tokens
Paste a JWT to decode its Base64URL header and payload as formatted JSON. Inspect claims, roles, and expiration without verifying the signature.
Number Base Converter — Binary, Hex & More
Convert numbers between decimal, hexadecimal, octal, and binary with prefixed outputs you can copy instantly.
HTML Entity Encoder & Decoder
Encode reserved HTML characters as entities or decode HTML entities back to readable text for snippets, CMS content, and templates.
Backslash Escape & Unescape Tool
Escape and unescape backslash sequences for JSON-like strings, regex samples, shell notes, and code literals.
Security
AES Encrypt & Decrypt — Browser-Based
Encrypt and decrypt text with passphrase-based AES in your browser. Useful for small private notes, demos, and CryptoJS-style ciphertext tests.
What Is My IP — Public Address Lookup
Check the public IPv4 and IPv6 addresses visible from your current network. Useful for VPN checks, allowlists, and support tickets.
Strong Password Generator — Cryptographically Secure
Generate strong random passwords with configurable length and character sets, including uppercase, lowercase, digits, and symbols.
IP Subnet Calculator — CIDR & Host Range
Calculate IPv4 CIDR network address, subnet mask, wildcard mask, broadcast address, host range, and usable hosts.
Generators
UUID Generator — RFC 4122 Version 4
Generate one or many RFC 4122 version 4 UUIDs for database rows, fixtures, filenames, and distributed systems.
Hash Generator — MD5, SHA-1, SHA-256 & SHA-512
Compute MD5, SHA-1, SHA-256, and SHA-512 hashes from text input. Use deterministic digests for checksums, comparisons, and fixtures.
QR Code Generator — URLs & Text
Create downloadable QR codes from URLs or text, adjust the pixel size, and preview the result instantly.
IndexNow API Key Generator
Generate a random hexadecimal IndexNow API key for search engine update notifications and key-file setup.
Lorem Ipsum Text Generator
Generate Lorem Ipsum placeholder text as paragraphs, sentences, or words for wireframes, mockups, and layout tests.
URL Slug Generator — SEO-Friendly Strings
Turn titles and phrases into clean SEO-friendly URL slugs with separators, lowercase control, and max length.
Formatters
JSON Formatter — Pretty Print & Minify
Validate strict JSON, pretty-print it with adjustable indentation, or minify it into compact output using the browser JSON parser.
Text Diff Checker — Side-by-Side Compare
Compare two text blocks line by line and highlight added, removed, and unchanged content in your browser.
Text Case Converter — camelCase, snake_case & More
Convert text into camelCase, PascalCase, snake_case, kebab-case, UPPER CASE, lower case, Title Case, and Sentence case.
YAML ↔ JSON Converter
Convert YAML to formatted JSON and JSON to YAML for config files, API examples, and infrastructure snippets.
SQL Formatter — Beautify Queries
Format SQL queries for Standard SQL, MySQL, PostgreSQL, SQLite, BigQuery, MariaDB, PL/SQL, and T-SQL.
Converters
Unix Timestamp Converter — Epoch to Human Date
Convert Unix timestamps in seconds to ISO dates, or convert local date-time input back to epoch seconds.
Cron Expression Parser — Schedule & Validate
Validate five-field cron expressions, read a plain-language summary, and preview the next five UTC run times.
CSS Unit Converter — px, rem, em & pt
Convert CSS px, rem, em, and pt values with a configurable base font size for design tokens, typography, and responsive layouts.
Image to Base64 — Data URI Encoder
Convert an image file up to 10 MB into a Base64 data URI with preview and copy-ready output.
Aspect Ratio Calculator — Resize Without Distortion
Calculate image and video aspect ratios, decimal ratios, and proportional resize dimensions without distortion.
Visualizers
AI Tools
LLM Token Calculator — GPT & Cost Estimate
Count tokens for supported GPT and reasoning models, compare tokenizer behavior, and estimate input or output cost from pasted text.
Regex Tester — Live Matches & Capture Groups
Test JavaScript regular expressions with live match highlighting, capture groups, and g, i, m flag controls.
String Counter — Characters, Words & Bytes
Count characters, characters without spaces, words, lines, sentences, and UTF-8 bytes for any text.