Util Monster Free

💻 Developer & Security Tools

Essential tools for development and security tasks

Security & Generators

Password Generator

Generate secure random passwords. Customize length and complexity settings.

Random Generator

Generate various types of random values including numbers, strings, and UUIDs.

Generate MD5, SHA-1, SHA-256, SHA-512 hashes for text and files.

Generate UUID v1, v4, v7. Support for single or bulk generation.

API Key Generator

Generate random API Keys in UUID, Base64, Hex and other formats.

Encoding & Conversion

Encoding Converter

Convert between various encoding formats like Base64, URL encoding, HTML entities.

Base64 Converter

Encode/decode text and images to Base64 format.

URL Encoder/Decoder

Encode or decode URLs. Handle special characters properly.

Convert to camelCase, PascalCase, snake_case, kebab-case and more (8 formats).

Base64 Image Converter

Convert images to Base64 or restore Base64 to images.

Convert between Binary, Octal, Decimal, and Hexadecimal.

Text Case Converter

Convert to UPPERCASE, lowercase, camelCase, snake_case and more.

Query String Builder

Build a query string from key=value rows, or parse one into a parameter table.

Text & Validation Tools

Test regex patterns and view matching results.

Check XML syntax errors and validate document structure.

Create word clouds to visualize word frequency in text.

Citation Generator

Generate citations in APA, MLA, Chicago and more formats.

SEO Score Calculator

Analyze your page SEO score and get improvement suggestions.

Compare two texts and highlight additions, deletions, and changes.

Format, minify, and validate JSON with a tree view of the structure.

Marketing & QR Tools

UTM Link Builder

Generate URLs with UTM parameters for campaign tracking.

Convert Wi-Fi info to QR code for easy sharing.

Barcode Generator

Generate CODE128, EAN13, UPC and other barcode formats.

Network & Data Tools

File Size Converter

Convert MB↔GB↔TB and other data units.

Speed Converter

Convert Mbps↔MB/s (internet speed).

IP Subnet Calculator

Calculate network address, subnet mask, and host range from IP address and CIDR.

IP Address Lookup

Check your current public IP address and location information.

WHOIS Domain Lookup

Query domain registration details, owner information, and expiration dates.

Break a URL down into protocol, host, port, path, query, and hash.

HTTP Status Code Reference

Every HTTP status code (1xx-5xx) with reason phrase, description, and RFC.

cURL Command Builder

Build a copy-ready cURL command from method, headers, and body.

MAC Address Generator

Generate random MAC addresses with separator, case, and OUI prefix options.

Data & Markup Tools

YAML JSON Converter

Convert between YAML and JSON formats and check for syntax errors.

Beautify SQL queries for better readability.

Decode JWT tokens to inspect the header, payload, and signature.

Markdown Editor

Write Markdown with a live preview.

AI Token Cost Calculator

Calculate AI API usage cost from prompt and completion token counts.

Numbers to Words

Convert numbers to words (cardinal/ordinal) in English or Korean.

UUID Validator & Decoder

Validate a UUID and decode its embedded timestamp.

JSON Schema Generator

Infer a draft-07 JSON Schema from a JSON sample.

ISO 8601 Date Formatter

Auto-detect a date/time and convert it into multiple formats at once.

SVG to React JSX Converter

Convert SVG to React JSX with attribute casing and style-object conversion.

LESS to CSS Compiler

Compile LESS to CSS instantly in your browser.

Device Tests

Microphone Test

Check mic input volume and quality in real time. Audio never leaves your browser.

Check webcam video and resolution right in your browser. Video never leaves your browser.

Test left/right channels and volume to check your speakers. Audio never leaves your browser.

Visually confirm every key press is detected.

Dead Pixel Test

Cycle through solid colors to find stuck or dead pixels on your monitor.

Text Cleanup

Remove Whitespace

Collapse or strip repeated spaces, convert tabs, and trim lines.

Remove Line Breaks

Replace or strip line breaks with a paragraph-preserving mode.

Remove Duplicate Lines

Remove duplicate lines, keeping only the first occurrence.

Blank Line Remover

Strip all blank lines or collapse consecutive ones into one.

Sort numbers ascending or descending with stats.

HTML to Text Converter

Strip HTML tags and extract clean plain text.

Word Frequency Analyzer

Analyze how often each word appears in your text.

Invisible Character Remover

Detect and remove zero-width chars, NBSP, and control characters.

Fun Text

Fancy Font Generator

Convert text into 15 Unicode fancy font styles at once — bold, italic, script, fraktur, double-struck and more. Copy-paste ready for Instagram/Discord bios. Runs entirely in your browser.

Small Caps Text Generator

Convert lowercase text into small-capital Unicode look-alike letters (ᴀʙᴄ...) for stylized usernames and headers. Copies as plain text anywhere. Runs entirely in your browser.

Upside Down Text Generator

Turn text upside down using visually mirrored Unicode characters. Substitutes each character and reverses the order so it reads correctly when actually flipped 180°.

Zalgo Text Generator

Turn normal text into glitchy "corrupted" Zalgo text by stacking combining marks above, in the middle, and below each character. Adjustable intensity 1-10 and per-zone toggles.

Classic Ciphers

Caesar Cipher Tool

Encrypt or decrypt text with the classic Caesar shift cipher, or use brute-force mode to see all 25 possible shifts at once. Educational/puzzle use only, runs entirely in your browser.

Vigenère Cipher Tool

Encrypt or decrypt text with the Vigenère cipher, a repeating-keyword polyalphabetic cipher once nicknamed "le chiffre indéchiffrable." Runs entirely in your browser, for education and puzzles.

Atbash Cipher Tool

Reverse the alphabet with the Atbash cipher — A becomes Z, B becomes Y, and so on. A keyless, self-inverse transform, so one button handles both directions. Educational/puzzle use, runs entirely in your browser.

ROT13 Encoder/Decoder

Encode or decode text with ROT13 (Caesar cipher fixed at shift 13). Includes an adjustable ROT-N shift (1-25) and a ROT47 mode that rotates letters, digits, and symbols. Runs entirely in your browser.

Morse Code Translator

Convert text to international Morse code and back again. Adjust the WPM speed and play the code back as real dot/dash audio tones. Runs entirely in your browser.

Pig Latin Translator

Convert English words to Pig Latin (hello → ellohay). Decoding back to English is an approximation. Runs entirely in your browser — nothing is sent to a server.