Developer Tools
Handy browser-based utilities I'm building — no install, no sign-up, just paste and go.
JSON Formatter & Validator
Format, validate, and minify JSON data with syntax highlighting and error detection.
Regex Tester
Test regular expressions with live matching, capture groups, and common pattern library.
Base64 Encoder / Decoder
Encode and decode Base64 strings instantly with support for text and file input.
URL Encoder / Decoder
Encode and decode URL components and full URLs with RFC 3986 compliance.
Hash Generator
Generate MD5, SHA-1, SHA-256, and SHA-512 hashes from any text input.
UUID Generator
Generate RFC 4122 v4 (random) and v7 (timestamp-sorted) UUIDs in bulk.
JWT Decoder
Decode JSON Web Tokens to inspect header, payload, and expiration status.
Color Converter
Convert colours between HEX, RGB, and HSL formats with live preview.
Timestamp Converter
Convert between Unix timestamps and ISO 8601 dates with relative time display.
Lorem Ipsum Generator
Generate placeholder text in paragraphs, sentences, or words.
Markdown Preview
Write Markdown and see rendered HTML in a live side-by-side preview.
HTML Entity Encoder / Decoder
Encode and decode HTML entities with a built-in reference table.
Diff Checker
Compare two texts side by side with colour-coded additions, removals, and statistics.
String Case Converter
Convert text between camelCase, PascalCase, snake_case, kebab-case, and 6 more formats instantly.
Text Counter
Count characters, words, sentences, paragraphs, lines, and estimate reading and speaking time.
Slug Generator
Generate URL-safe slugs from any text with customizable separator, length, and diacritic transliteration.
Text Sorter
Sort lines alphabetically, numerically, by length, or randomly — with deduplication and blank-line removal.
String Escaper
Escape and unescape strings for JSON, JavaScript, HTML, RegExp, CSV, SQL, and XML formats.
Text Reverser
Reverse entire text, individual word characters, line order, or word order within each line.
Whitespace Cleaner
Trim, normalize, and remove excess whitespace — tabs to spaces, collapse runs, strip blank lines.
Number to Words
Convert numbers to their written-out word equivalents in English and German, cardinal or ordinal.
Number Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal with simultaneous multi-base output.
ASCII / Unicode Table
Browse the full ASCII and Unicode character table with code points, HTML entities, and category filters.
Morse Code Translator
Translate text to Morse code and back with optional audio playback.
ROT13 / Caesar Cipher
Encode and decode text with ROT13, ROT47, Caesar shift, and Atbash ciphers.
QR Code Generator
Generate styled QR codes with custom colors, dot shapes, gradients, and logo. Download as PNG or SVG.
Punycode Encoder / Decoder
Encode international domain names to Punycode (ACE) and decode ACE labels back to Unicode.
URI Parser
Decompose any URI into protocol, host, port, path, query parameters, and fragment.
JSON ↔ YAML Converter
Convert between JSON and YAML formats instantly with syntax validation and pretty-printing.
JSON ↔ CSV Converter
Convert JSON arrays to CSV spreadsheets and parse CSV back to JSON with configurable delimiters.
JSON ↔ XML Converter
Convert JSON objects to XML and XML documents back to JSON with attribute and namespace handling.
CSV Viewer
Paste CSV data and view it as a sortable, filterable table with column detection.
XML Formatter
Prettify or minify XML documents with configurable indentation and syntax validation.
JSONPath Evaluator
Evaluate JSONPath expressions against any JSON document and inspect the matched results.
JSON Schema Validator
Validate JSON data against a JSON Schema (draft-07) and get detailed error messages.
JSON to TypeScript Types
Generate TypeScript interfaces and type definitions from any JSON object or array.
Password Generator
Generate cryptographically-secure passwords with configurable length, character sets, and bulk generation.
Password Strength Checker
Analyse password entropy, crack-time estimates, and character diversity with detailed feedback.
HMAC Generator
Generate HMAC message authentication codes using SHA-256, SHA-384, or SHA-512 with any secret key.
AES Cipher
Encrypt and decrypt text with AES-GCM, AES-CBC, or AES-CTR using a base64-encoded key
TOTP / 2FA Generator
Generate time-based one-time passwords (TOTP / RFC 6238) for two-factor authentication testing.
CSP Header Builder
Build Content Security Policy headers interactively with directive explanations and copy-ready output.
SSL Certificate Decoder
Decode PEM certificates to inspect subject, issuer, validity dates, and extensions.
Cron Expression Parser
Parse cron expressions, see the next execution times, and generate expressions from natural language.
Regex Pattern Library
Browse a curated library of common regular expression patterns organised by category.
HTTP Status Codes
Browse all HTTP status codes with meaning, RFC reference, and usage guidance.
MIME Type Lookup
Look up MIME types by file extension or search by content-type string.
User-Agent Parser
Parse User-Agent strings to identify browser, OS, device type, and engine.
IP / CIDR Calculator
Calculate subnet masks, network addresses, broadcast addresses, and host ranges from CIDR notation.
chmod Calculator
Calculate Unix file permission octals interactively with read/write/execute toggles for owner, group, and others.
Git Command Reference
Browse and search a curated reference of Git commands with descriptions, flags, and usage examples.
SQL Formatter
Format and prettify SQL queries with configurable indentation and dialect support.
CSS Minifier
Minify CSS stylesheets by removing whitespace, comments, and redundant code.
JavaScript Minifier
Minify JavaScript by removing whitespace and comments for reduced file size.
HTML Formatter
Prettify or minify HTML documents with configurable indentation.
SVG Optimizer
Optimise SVG files by removing metadata, comments, and redundant attributes.
Code Screenshot
Turn code snippets into beautiful screenshots with syntax highlighting and customizable themes.
Fake Data Generator
Generate realistic mock data for testing: names, emails, addresses, and more.
Random Number Generator
Generate cryptographically-secure random numbers, ranges, and sequences.
Color Palette Generator
Generate harmonious color palettes from a base color using complementary, triadic, and analogous schemes.
CSS Gradient Builder
Build and preview CSS linear and radial gradients with a visual editor.
Box Shadow Generator
Create CSS box-shadow declarations visually with live preview.
Border Radius Generator
Craft custom CSS border-radius shapes with an interactive visual editor.
Unit Converter
Convert between length, weight, temperature, area, and digital storage units.
Crypto Unit Converter
Convert between BTC, satoshi, mBTC, wei, gwei, and ether with BigInt precision.
Crypto Address Validator
Validate Bitcoin (Legacy, SegWit, Taproot), Ethereum (EIP-55), and Solana addresses.
BIP39 Mnemonic Tool
Generate and validate BIP39 mnemonic seed phrases (12–24 words) using your browser’s secure RNG.
Merkle Tree Builder
Build and visualise a SHA-256 Merkle hash tree from input leaf values.
EVM Function Selector
Compute Keccak-256 function selectors and event topic hashes from Solidity signatures.
Blockchain Explorer Links
Generate explorer URLs for transactions, addresses, and blocks across all major chains.
Docker Command Reference
Browse and build Docker CLI commands with an interactive parameter builder.
PowerShell Reference
Browse and build PowerShell cmdlets with an interactive parameter builder.
Bash Reference
Browse and build Bash commands with an interactive parameter builder.
AI Code Explainer
Paste code and get a clear, structured explanation powered by AI.
AI Regex Generator
Describe a pattern in plain language and get a working regex with explanation.
AI Commit Message
Paste a git diff and get a well-structured commit message following conventional formats.
AI SQL Generator
Describe a query in plain language and get production-ready SQL for your database.
AI Code Converter
Convert code between languages — JS, Python, C#, Go, Rust and more.
AI Test Generator
Paste a function and get comprehensive unit tests in your chosen framework.
AI Mock Data
Describe a data shape in plain English and get realistic mock JSON objects.
AI CSS Generator
Describe a UI element and get production CSS or Tailwind utility classes.
AI Code Review
Paste code and get structured review feedback with severity levels for bugs, security, and style.
AI API Docs
Paste a route handler and get OpenAPI 3.1 YAML documentation generated automatically.
AI API Spec
Describe your API in plain language and get a complete OpenAPI 3.1 YAML specification.
AI Changelog
Paste your git commit log and get a formatted Keep a Changelog entry ready to ship.
AI Cron Generator
Describe when a job should run in plain English and get the correct cron expression instantly.
AI Dockerfile
Describe your application stack and get a production-ready Dockerfile following best practices.
AI Error Explainer
Paste any error or stack trace and get a clear explanation with root cause analysis and fix steps.
AI GitHub Actions
Describe your CI/CD workflow and get a complete GitHub Actions YAML ready to commit.
AI README Generator
Describe your project and get a complete, professional README.md ready to push to GitHub.
AI Shell Command
Describe what you want to do and get the correct shell command with a step-by-step breakdown.
Exit Code Reference
Look up POSIX, curl, Node.js, and Docker exit codes with descriptions and common causes.
Linux Signal Reference
Browse POSIX signals with numbers, default actions, catchability, and practical examples.
DNS Record Reference
Browse all DNS record types with syntax, examples, and RFC references.
Port Number Reference
Browse well-known TCP/UDP ports with protocols, services, and security notes.
HTTP Header Reference
Browse all HTTP request, response, security, CORS, and caching headers with usage guidance.
Environment Variable Reference
Browse common environment variables for POSIX, Windows, Node.js, Python, Docker, and CI/CD.
kubectl Command Reference
Browse kubectl commands with flags, examples, and tips for Kubernetes cluster management.
YAML Reference
Browse YAML syntax with live parsed-value previews, gotchas, and encoding patterns.
SQL Reference
Browse SQL keywords with syntax, examples, and dialect notes for PostgreSQL, MySQL, and SQLite.
Unicode Explorer
Identify Unicode codepoints, encoding formats, and browse characters by category.
Markdown Reference
Browse Markdown syntax with side-by-side rendered previews and GFM extensions.
.gitignore Reference
Browse .gitignore syntax patterns and copy pre-built templates for popular languages and tools.
nginx Reference
Browse nginx directives with syntax, defaults, context badges, and configuration examples.
OpenAPI / Swagger Viewer
Paste or upload an OpenAPI 3.x / Swagger 2.0 spec and browse endpoints, schemas, and parameters in a readable UI.
GraphQL Formatter
Format and validate GraphQL queries, mutations, and schema definitions with syntax highlighting.
JWT Generator
Generate JSON Web Tokens with custom claims, algorithm selection (HS256/RS256), and configurable expiry.
CORS Policy Tester
Build and test Cross-Origin Resource Sharing (CORS) headers, origins, and preflight responses.
JSON Diff / Patch
Compare two JSON documents and view added, removed, and changed fields. Generate RFC 6902 JSON Patch output.
curl Command Converter
Convert curl commands to JavaScript fetch, axios, PowerShell Invoke-RestMethod, and Python requests.
HTTP Methods Reference
Complete reference for HTTP methods: semantics, idempotency, safety, request body support, and common use cases.
OAuth 2.0 Flow Debugger
Visualise OAuth 2.0 grant flows (authorization code, client credentials, implicit, PKCE) and decode access tokens.
TOML Formatter
Format and validate TOML configuration files. Normalises key spacing, section structure, and blank lines.
INI ⇔ JSON Converter
Convert between INI configuration files and JSON objects bidirectionally.
Email Address Validator
Validate email address syntax against RFC 5321 / RFC 5322 rules. Shows local part, domain, and specific issues.
IBAN Validator
Validate IBAN codes. Verifies MOD-97 checksum, format, and country-specific length rules.
Phone Number Formatter
Format phone numbers into E.164, international, and national formats. Detects country from the dialling code.
Semver Range Calculator
Check if a version satisfies a semver range and calculate the next major, minor, or patch bump.
JSON-LD / Schema.org Editor
Format and inspect JSON-LD documents. Extracts @context, @type, and linked data properties.
HCL (Terraform) Formatter
Format HashiCorp Configuration Language (HCL) files used by Terraform, Consul, and Vault.
Contrast Checker
Check WCAG colour contrast ratios between foreground and background colours.
Colour Blind Simulator
Simulate how a colour appears to people with deuteranopia, protanopia, or tritanopia.
ARIA Role Reference
Browse all WAI-ARIA 1.2 roles with required and allowed attributes.
Timezone Converter
Convert a date and time between any two IANA timezones instantly.
Date Calculator
Add or subtract days/weeks/months/years from a date, or find the difference between two dates.
Working Days Calculator
Count working days between two dates, excluding weekends and optional public holidays.
Epoch Batch Converter
Convert multiple Unix timestamps to human-readable dates in one paste.
TZ Abbreviation Reference
Look up timezone abbreviations (EST, CET, JST…) and find their IANA equivalents.
Flexbox Playground
Visually build CSS flexbox layouts and copy the generated CSS.
CSS Grid Playground
Interactively configure CSS Grid layouts and export the generated CSS.
CSS Animation Builder
Build CSS @keyframe animations visually and copy the generated code.
Tailwind ↔ CSS Converter
Convert Tailwind utility classes to plain CSS and back.
Spacing Scale Generator
Generate and preview CSS spacing scales based on Tailwind, 8px grid, golden ratio, or custom multiplier.
Glassmorphism Generator
Design glassmorphism card effects with live preview and copy the generated CSS.
Favicon Generator
Create text or emoji favicons in multiple sizes using the Canvas API, then copy as PNG data URLs.
Placeholder Image Generator
Generate SVG placeholder images in any size and colour for use during development.
Terraform Reference
Blocks, meta-arguments, built-in functions and expressions for Terraform HCL.
GitHub Actions Reference
Triggers, job fields, step fields, contexts, and expressions for GitHub Actions workflows.
Helm Chart Reference
Template variables, functions, directives, and lifecycle hooks for Helm chart development.
Dockerfile Reference
All Dockerfile instructions with syntax, descriptions, and best-practice examples.
Docker Compose Reference
Service, network, volume, and deploy fields for Docker Compose file authoring.
systemd Reference
Unit file directives for [Unit], [Service], [Install], [Timer], and [Socket] sections.
Makefile Reference
Rules, variables, functions, directives, and automatic variables for GNU Make.
CI Environment Variables
Predefined environment variables for GitHub Actions, GitLab CI, Jenkins, Azure Pipelines, and CircleCI.
SSH Key Generator
Generate ECDSA or RSA SSH key pairs in your browser — keys never leave your device.
Self-Signed Certificate
Generate a self-signed X.509 certificate and private key entirely in your browser.
DKIM Key Generator
Generate a DKIM RSA key pair and DNS TXT record for email authentication.
OWASP Security Headers
Generate security response headers following OWASP best practices for your web application.
SRI Hash Generator
Generate Subresource Integrity hashes for external scripts and stylesheets.
Robots.txt Generator
Generate a robots.txt file to control crawler access to your website.
.htaccess Generator
Generate Apache .htaccess rules for redirects, caching, security headers, and more.
PGP Key Viewer
Parse and inspect PGP/GPG public key blocks to view key metadata.
TypeScript Reference
Searchable reference for TypeScript types, utility types, generics, and type constructs.
CSS Selectors Reference
Searchable reference for CSS selectors, combinators, pseudo-classes, and pseudo-elements.
React Hooks Reference
Searchable reference for all React hooks including state, effects, context, and React 19 hooks.
Python Built-ins Reference
Searchable reference for Python built-in functions, type conversions, iteration tools, and I/O.
C# Reference
Searchable reference for C# types, collections, LINQ, async/await, string methods, and exceptions.
REST API Reference
Searchable reference for HTTP methods, status codes, design principles, and common headers.
HTML Elements Reference
Searchable reference for HTML elements with attributes, semantics, and usage examples.
Regex Syntax Reference
Searchable reference for regex patterns including character classes, quantifiers, anchors, groups, and lookaround.
Gzip Estimator
Estimate gzip compression size and ratio for any text or code.
Hex Editor
View file and text contents as a formatted hex dump.
Image to Base64
Convert images to Base64 encoded data URIs for embedding in HTML or CSS.
Data URI Generator
Convert any file to a Base64 data URI ready for embedding.
Base Converter
Convert numbers between binary, octal, decimal, and hexadecimal.
Byte Calculator
Convert between byte units — B, KB, MB, GB, TB, KiB, MiB, GiB, TiB.
Image Resizer
Resize images in the browser using the Canvas API. No upload required.
ICO / Favicon Generator
Generate multi-size favicon PNG sets (16×16, 32×32, 48×48, 64×64, 128×128) from any image.
Workflow Builder
Chain tool operations into automated text-processing pipelines
RSA Cipher
Encrypt and decrypt data with RSA-OAEP using Web Crypto API
ChaCha20-Poly1305
Authenticated encryption and decryption with ChaCha20-Poly1305 (RFC 8439)
Digital Signatures
Sign and verify messages with Ed25519, ECDSA, and RSA-PSS
File Encryptor
Encrypt and decrypt files with AES-256-GCM and PBKDF2 key derivation — entirely in your browser
PGP Cipher
Generate RSA key pairs, encrypt and decrypt messages with PGP-style hybrid encryption
ECDH Key Exchange
Demonstrate Elliptic-Curve Diffie–Hellman key agreement with NIST curves and HKDF key derivation
Key Derivation
Derive cryptographic keys from passwords using PBKDF2, HKDF, and Scrypt
Triple DES (3DES)
Encrypt and decrypt data using DES, 3DES-EDE2, and 3DES-EDE3 block ciphers
Blowfish Cipher
Encrypt and decrypt data using the Blowfish symmetric block cipher with variable-length keys
Envelope Encryption
Encrypt data with a random DEK, then wrap the DEK with a KEK — the industry-standard pattern used by AWS KMS, GCP CMEK, and Azure Key Vault.
Caesar & Vigenère Cipher
Encrypt and decrypt text with classical substitution ciphers — Caesar, Vigenère, ROT13, Atbash, and Affine — with brute-force and frequency analysis.
XOR Cipher
XOR encrypt/decrypt data with repeating keys, analyse single-byte XOR ciphertexts, and detect key lengths via Hamming distance.
One-Time Pad
Encrypt and decrypt messages using the only mathematically unbreakable cipher — the One-Time Pad (Vernam cipher).
Enigma Machine
Simulate the historic Wehrmacht Enigma I cipher machine with authentic rotor wirings, plugboard, and double-stepping.
Steganography
Hide secret messages inside images using LSB (Least Significant Bit) encoding — invisible to the naked eye.
Emoji Picker
Search, browse, and copy 1,906 Unicode emoji — skin-tone modifiers, version filters, and five copy formats.