All Developer Tools
43 free tools for developers. Search or filter by category.
Add Line Numbers
Add line numbers to any text. Formats with aligned padding and a separator — ready for code reviews, documentation, or sharing.
Add Prefix & Suffix to Lines
Add a prefix, suffix, or both to every line of text. Wrap lines in quotes, HTML tags, or any custom string.
Base64 Decoder
Decode Base64 strings back to plain text online. Handles standard Base64 and UTF-8 encoded content. Free, fast, client-side.
Base64 Encoder
Encode any text to Base64 online. Supports UTF-8 characters including accents, CJK text, and emoji. Free, fast, client-side.
Case Converter
Convert text between UPPERCASE, lowercase, Title Case, camelCase, PascalCase, snake_case, kebab-case, and CONSTANT_CASE instantly.
Character Counter
Count characters with and without spaces, plus words, lines, sentences, and reading time. Real-time analysis for any text.
Color Converter — HEX, RGB, HSL
Convert colors between HEX, RGB, and HSL formats. Pick a color visually or enter values directly. Copy CSS-ready color codes.
Cron Expression Parser & Generator
Parse, validate, and generate cron expressions online. See human-readable schedule descriptions and next execution times instantly.
Diff Checker — Text Compare
Compare two texts side-by-side and see the differences highlighted. Find added, removed, and unchanged lines instantly.
Duplicate Line Remover
Remove duplicate lines from text while preserving order. Paste a list, get unique lines instantly.
Empty Line Remover
Remove all blank lines from text. Clean up code, logs, or data files by stripping empty lines in one click.
Hash Generator (MD5 & SHA-256)
Generate MD5 and SHA-256 hashes from any text input. Compare hashes, verify data integrity, and more.
Hex Decoder (Hex to Text)
Convert hexadecimal byte values back to readable text. Accepts space-separated, comma-separated, or continuous hex strings.
Hex Encoder (Text to Hex)
Convert text to its hexadecimal byte representation. Each byte is shown as a two-digit hex value, space-separated.
HTML Entity Decoder
Decode HTML entities back to their original characters. Convert <, &, " and numeric entities to readable text.
HTML Entity Encoder
Encode special characters to HTML entities. Prevents XSS attacks and ensures HTML code displays correctly on web pages.
JSON Formatter & Beautifier
Format, beautify, and pretty-print JSON data online. Choose indentation style, copy or download the result. Free, fast, and private.
JSON to CSV Converter
Convert JSON arrays of objects to CSV format online. Automatically detects columns, handles nested data, and escapes special characters.
JSON to YAML Converter
Convert JSON data to YAML format online. Clean, readable YAML output from any valid JSON input.
JSON Tree Viewer
Visualize JSON data as an interactive, collapsible tree. Explore nested objects and arrays with ease.
JSON Validator
Validate your JSON data instantly. Check for syntax errors, see detailed error messages, and get document statistics.
JWT Decoder
Decode and inspect JSON Web Tokens (JWT) online. View header, payload, claims, and expiration status without any server.
Line Counter
Count lines, words, characters, sentences, and paragraphs in any text. Real-time text statistics with reading time estimate.
Line Sorter
Sort lines alphabetically, by length, naturally, or randomly. Remove duplicates and trim whitespace. Supports ascending, descending, and custom sort modes.
Log Parser & Viewer
Parse, filter, and analyze log files in your browser. Supports syslog, nginx, JSON lines, Docker, and custom formats. No upload — all processing happens locally.
Lorem Ipsum Generator
Generate placeholder text for your designs and layouts. Choose the number of paragraphs and copy the result instantly.
Password Generator
Generate strong, random passwords with customizable length and character sets. Uses cryptographically secure randomness.
Regex Tester & Debugger
Free online regex tester. Test regular expressions in real time with match highlighting, capture groups, and flag toggles — all in your browser.
Remove Line Numbers
Strip line numbers from text. Handles common formats: '1 | ', '1: ', '1. ', '1) ', '1] '.
ROT13 Decoder
Decode ROT13-encoded text back to plain text. The same shift-by-13 operation that encodes also decodes.
ROT13 Encoder
Encode text using the ROT13 cipher. Shifts each letter by 13 positions in the alphabet. Numbers and symbols are unchanged.
SQL Formatter
Format and beautify SQL queries online. Add proper indentation, capitalize keywords, and make your SQL readable.
Text Reverser
Reverse any text character by character. Handles Unicode, emoji, and multi-byte characters correctly.
Unicode Escape
Convert non-ASCII characters to Unicode escape sequences (\uXXXX). Keep ASCII text readable while escaping everything else.
Unicode Unescape
Convert Unicode escape sequences (\uXXXX) back to readable characters. Supports both \uXXXX and \u{XXXXX} formats.
Unix Timestamp Converter
Convert Unix timestamps to human-readable dates and vice versa. Supports seconds and milliseconds.
URL Decoder
Decode percent-encoded URL strings back to readable text. Convert %20, %26, %3D and other encoded sequences to their original characters.
URL Encoder
Encode special characters for safe use in URLs. Convert spaces, ampersands, and other characters to percent-encoded format.
URL Slug Generator
Convert any text into a clean, URL-friendly slug. Remove special characters, accents, and spaces automatically.
UUID Generator
Generate random UUIDs (v4) and sortable UUIDs (v7) instantly. Copy single or batch-generate multiple UUIDs at once.
Whitespace Cleaner
Clean up messy whitespace: trim lines, collapse multiple spaces, remove blank lines, and normalize line endings. Configurable options.
Word Counter
Count words, characters, sentences, paragraphs, and estimate reading time. Real-time text analysis — just paste and see the results.
YAML to JSON Converter
Convert YAML to JSON format online. Transform configuration files and data from YAML to standard JSON.
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Browse by Category
JSON Tools
Format, validate, view, and convert JSON data with free online tools.
4 tools →Encoders & Decoders
Encode and decode Base64, URL, JWT, HTML entities and more.
13 tools →Code Formatters
Beautify and format SQL queries and other code online.
1 tool →Generators
Generate UUIDs, passwords, Lorem Ipsum, hashes and more.
3 tools →Data Converters
Convert between JSON, CSV, and YAML formats online.
2 tools →Text Utilities
Diff checker, word counter, case converter, slug generator and more.
15 tools →Date & Time
Unix timestamp converter and cron expression parser.
2 tools →Hash & Crypto
Generate MD5 and SHA-256 hashes for checksums and integrity verification.
1 tool →Regex
Test and debug regular expressions with real-time matching.
1 tool →Color Tools
Convert between HEX, RGB, HSL color formats and pick colors.
1 tool →