Release Notes & Catalog

V1.4· What's new, what's inside, and every tool at a glance
6 releases113 tools

Release History

newest first · click a version to expand
V1.4FeatureV1.4 — 14 new tools, cross-tool pipelines, shareable URLs, PWA + browser extension2026-05-27

Four new tool directions land fully implemented: Networking & Web (Webhook Receiver, WebSocket Tester, CORS Tester, DNS Lookup), Diff & Compare additions (Image Diff, CSV Diff), a new Image & Media category (Image Compressor, SVG Optimizer, Favicon Generator, Color Palette Extractor, EXIF Viewer), and Data Conversion additions (Mock Data Generator, TOML Converter, TOON Converter) — all 14 functional, no placeholders. The same release changes how the toolkit feels: tools hand off output to each other, every input has a Share button that round-trips to a URL fragment, the PWA manifest ships with an install button, and a Manifest V3 browser extension opens any selection in a tool. The AI category grows to 6 tools — all key-free, server-free, and local.

New category — Image & Media (5 tools, all client-side)
  • **Image Compressor** — Canvas re-encode with quality slider, JPEG/WebP/PNG output, optional max-dimension resize, live before/after preview.
  • **SVG Optimizer** — strips editor metadata (Inkscape/Sketch/Figma), collapses whitespace, rounds numeric precision with a 0–6 decimal slider, side-by-side rendered preview.
  • **Favicon Generator** — produces 7 sizes (16/32/48/96/180/192/512) from one source, with HTML head snippet and PWA manifest scaffolds.
  • **Color Palette Extractor** — k-means in RGB space at 200px downsample, configurable palette size 3–16, HEX/RGB/HSL per swatch.
  • **EXIF Viewer** — in-browser EXIF parser for JPEG/TIFF; groups Camera/Lens/Capture/Image/GPS tags, decodes GPS to decimal lat/lon with map link.
Networking & Web (4 tools)
  • **Webhook Receiver** — generates a unique inbound URL, captures any HTTP request, surfaces method/headers/query/body live. Uses a new `/api/webhook/[sessionId]` endpoint with in-memory store (1h idle TTL, 200 requests/session).
  • **WebSocket Tester** — real ws/wss client with connection state, text frame send, timestamped history.
  • **CORS Tester** — sends real fetch from browser, classifies failures as preflight vs simple-request, decodes them into plain English.
  • **DNS Lookup** — DoH client (Cloudflare/Google), parallel A/AAAA/CNAME/MX/TXT/NS/SOA/CAA/SRV lookups, zone-file-format copy.
Diff & Compare (2 tools)
  • **CSV Diff** — RFC 4180 parser, key-column row matching, column-level change highlighting, copyable audit report.
  • **Image Diff** — pixel-by-pixel comparison with side-by-side, overlay (with opacity slider) and difference modes; tolerance slider and changed-pixel stats.
Data Conversion (3 tools)
  • **Mock Data Generator** — schema builder with 15 field types, seedable Mulberry32 RNG for reproducible fixtures, JSON/CSV/SQL output.
  • **TOML Converter** — TOML ↔ JSON ↔ YAML with a minimal in-file TOML parser (sections, scalars, arrays of scalars).
  • **TOON Converter** — JSON or XML → TOON (Token-Oriented Object Notation). Tabular array detection emits CSV-like rows instead of repeating keys; live characters-saved and approximate tokens-saved badges for LLM prompt budgeting.
Generators (1 tool)
  • **Credit Card Generator** — Luhn-valid test card numbers across 14 brands (Visa, Mastercard, American Express, Discover, JCB, Diners Club, Maestro, UnionPay, RuPay, Elo, Hipercard, Mir, Troy, InterPayment), each with a brand-correct IIN prefix, supported length, matching CVV width, future expiry and holder name. Numbers render on a card-style face and export as plain text, CSV or JSON. Brand data and the Luhn helpers moved to a shared `src/lib/credit-card.ts` that the Credit Card Validator now imports, so detection and checksum logic live in one place.
Infrastructure
  • New **Image & Media** category — colour, icon, description, order, union type.
  • New `/api/webhook/[sessionId]` and `/api/webhook/[sessionId]/events` routes (long-poll); shared in-memory store at `src/lib/webhook-store.ts`.
  • `ServerProxyNotice` extended with two new route ids (`proxy-stream`, `webhook`).
  • All 14 tools added to `tool-url-table.ts`, `tools-registry.ts` and `seo-content.ts` — full SEO + structured data from day one.
Cross-tool pipelines
  • New typed `ToolPayload` contract (`kind`, `data`, `sourceToolId`, `label`) in `src/lib/tool-bridge.ts` — payloads route through `sessionStorage` with a 1-minute TTL so the handoff survives client navigation.
  • `SendToButton` drops into any tool's output header; the dropdown is auto-populated from the tool registry based on what the target accepts.
  • `ToolBridgeBanner` reads a pending payload on the receiver's mount and auto-imports (configurable). Old payloads are cleared without applying so they never surprise the user.
  • 5 flagship tools wired as reference: **JSON Formatter, Base64, URL Encoder, Hash Generator, JWT Decoder**. ~10 lines per tool to adopt — the other 99 tools can follow incrementally.
Shareable URLs
  • `src/lib/shareable-state.ts` — typed `ShareSchema<T>` + `useShareableState` hook. State serialises to `JSON → deflate-raw → base64url` and lives in the URL **fragment** (never sent to a server, even for the public site).
  • `ShareButton` opens a modal that builds the link on demand (always reflects current input), shows char count, and warns when sensitive fields are present (JWT decoder uses this).
  • Schema versioning enforced — a link with `v: 2` ignored by a tool still on `v: 1`, no silent state corruption.
  • Same 5 flagship tools restore state on mount via the share URL.
PWA polish
  • **Fixed**: `/manifest.webmanifest` was referenced from `src/app/layout.tsx` but didn't exist on disk. Created the file with full metadata, 7 icon entries, 4 shortcuts (JSON / JWT / API Builder / Base64).
  • `PwaInstallButton` surfaces the deferred `beforeinstallprompt` event when the browser fires it and auto-hides in `display-mode: standalone`. Added to the footer.
  • Service worker already existed (`public/sw.js`, network-first navigation + runtime cache). No changes needed.
Browser extension (Manifest V3)
  • New `extension/` directory — plain JS, no bundler, so users can audit every line before installing.
  • Right-click any selected text → submenu with: Format JSON · Decode JWT · Base64 encode/decode · URL encode/decode · Generate hashes · Test with regex.
  • Reuses the same share-URL format as the main app — handoff is a single round trip with no extra protocol.
  • Toolbar popup with quick-launch shortcuts and a self-hosted origin override (for users running mydevtools privately).
  • Zero telemetry, zero `host_permissions` — the extension only sees what you select.
Honest AI, no keys required
  • **Semantic Search Playground** replaces the old keyword-matching `rag-search` demo with real sentence embeddings (all-MiniLM-L6-v2, WebGPU/WASM via `@huggingface/transformers`) — genuine meaning-based search, computed entirely in your browser. Model loads only on explicit click, never automatically.
  • **LLM Token Counter** — exact BPE token counts for GPT models via `gpt-tokenizer`, labeled estimates for Claude/Llama, plus a context-budget bar.
  • **Fine-Tuning Dataset Validator** — validates JSONL datasets against OpenAI or Anthropic message schemas, line by line, entirely client-side.
  • **Agent Card / MCP Manifest Generator** — builds a valid A2A `agent-card.json` or MCP server config with live validation, sendable straight into the existing A2A/MCP inspectors.
  • Deleted `code-explainer` and `text-summarizer` — both were regex/heuristic demos mislabeled as AI, unreachable from navigation since they were written.
Pipeline adoption + a live bug fix
  • 17 of 24 declared `BRIDGE_TARGETS` were silently dropping payloads sent via "Send to" — every one is now wired or the row was removed. Formatters, validators, converters, and diff tools all participate now (~30 tools total, up from the original 5).
  • TOON Converter gained a real decoder (TOON → JSON/XML, not just the reverse), a direction toggle, and swapped its character-based "savings" claim for actual token counts.
  • A new `scripts/check-parity.js` guard runs on every build, catching registry/SEO/orphan-tool drift and unwired bridge targets before they ship again.
Cross-cutting fixes
  • Every tool page now shows a **Related tools** section and renders **FAQ** content inline (previously JSON-LD only) — both computed from existing registry/SEO data, zero per-page changes.
  • Deleted ~2,500 lines of inert `generateMetadata` exports left over in client components from before the SEO layout pattern existed.
  • 34 pages moved off raw `navigator.clipboard` onto the shared helper with its `execCommand` fallback — copy no longer silently fails in non-secure contexts.
  • 95 icon-only buttons across 31 pages gained `aria-label`s.
  • "100% Client-Side" tagline retired in favor of "Client-side by default" — accurate for the 8 tools that do hit a server route (already disclosed per-tool, just not reflected site-wide).

Full commit history on GitHub.

What's Inside — Full Catalog

113 tools across 15 categories

Every tool below runs entirely in your browser — paste tokens, certs, passwords, or payloads without any data leaving your machine. Click any tool to open it instantly.

🔑Decode a JWT — see claims, expiry, and signature details locally🔒Inspect a TLS cert — domain never sent to any third party🔐Test a bcrypt hash — your plaintext stays in your tab📡Build an API request with a local CORS proxy — headers stay private📝Format a 10 MB JSON file — no upload, no timeout, no size limit
Artificial Intelligence6 tools
Protocol inspectors, token/dataset tooling, and semantic search — all local, no API key required
A2A Inspector
Test Agent-to-Agent protocol agents: view the agent card, validate spec compliance, chat, and inspect raw JSON-RPC 2.0 messages
Agent Card / MCP Manifest Generator
Build a valid A2A agent-card.json or MCP server config, then send it straight to the A2A or MCP inspector to test
Fine-Tuning Dataset Validator
Validate JSONL fine-tuning datasets against OpenAI or Anthropic message schemas — entirely in your browser
LLM Token Counter
Count tokens and estimate context-window usage across GPT, Claude, and open models
MCP Inspector
Connect to any Model Context Protocol server, browse tools, and call them interactively over SSE or HTTP
Semantic Search Playground
Real embedding-based search over your own text, computed entirely in your browser — no server, no API key
Diff & Compare5 tools
Compare documents side by side with highlighted differences
CSV Diff
Row-keyed CSV comparison with column-level change highlighting — handles added, removed, and modified rows
Image Diff
Pixel-perfect visual comparison: side-by-side, overlay, and difference modes with adjustable tolerance
JSON Diff
Compare two JSON documents side by side with highlighted differences
Text Diff
Compare any two text blocks with line-by-line diff highlighting
XML Diff
Compare two XML documents side by side with highlighted differences
API & Web Services6 tools
REST, SOAP, WSDL: build and inspect web service requests
API Request Builder
Build and test HTTP requests with headers, body, and authentication
JSONPath Tester
Test and evaluate JSONPath expressions against JSON data
SOAP Client
Test SOAP web services by sending requests and viewing responses
Swagger / OpenAPI Viewer
Paste or upload an OpenAPI spec and get interactive API documentation
URL Parser
Parse and analyze URLs into components: protocol, host, path, query, fragment
WSDL Parser
Parse and visualize WSDL files, view services, ports, operations, and messages
Encoding & Decoding7 tools
Encode and decode text: Base64, URL, HTML, Unicode, Gzip
Base64 Encode / Decode
Encode and decode Base64 strings instantly
Gzip Compress / Decompress
Compress and decompress text using Gzip with Base64 encoding
Hex Encoder / Decoder
Encode text to hexadecimal and decode hex strings back to text (UTF-8)
HTML Entities Encoder
Encode and decode HTML entities and special characters
String Escape / Unescape
Escape and unescape strings for JSON, XML, HTML, JavaScript, SQL, and CSV
Unicode Converter
Convert text to/from Unicode escape sequences, code points, and UTF-8 hex
URL Encode / Decode
Encode and decode URL components
Certificates & Keys7 tools
X.509 certificates, SSH keys, PKI tooling, and SSL inspection
Certificate & CSR Generator
Generate self-signed X.509 certificates and Certificate Signing Requests (CSR) with RSA / ECDSA keys
Certificate Chain & SSL
Inspect live server certificate chains, validate trust hierarchy, and decode every cert field — all locally via direct TLS connection
Certificate Inspector
Decode, fingerprint, convert, and parse X.509 certificates — PEM, DER, CRT, CER. Fetch live from any URL.
Java KeyStore (JKS) Tool
Create, view, and manage Java KeyStore files - import/export certificates and keys
Key Pair Generator
Generate RSA, ECDSA, and Ed25519 key pairs in PEM and other formats
PKCS#12 / PFX Tool
Create, extract, and convert PKCS#12/PFX files containing certificates and private keys
SSH Key Generator
Generate SSH key pairs (RSA, ECDSA, Ed25519) with optional passphrase protection
Cryptography8 tools
Hashing, HMAC, JWT, JWS, JWE, and JWK key generation
AES Encrypt & Decrypt
Encrypt and decrypt text using AES-128/192/256 with passphrase or key
BCrypt Hash & Verify
Generate BCrypt hashes for passwords and verify passwords against existing hashes
Hash Generator
Generate MD5, SHA-1, SHA-224, SHA-256, SHA-384, SHA-512, SHA-3, RIPEMD-160 hashes
HMAC Generator
Generate HMAC signatures using SHA-1, SHA-256, SHA-384, SHA-512 algorithms
JWE Encrypt & Decrypt
Encrypt and decrypt data using JSON Web Encryption (JWE) with RSA and AES algorithms
JWK Generator
Generate JSON Web Keys (JWK) for RSA, EC, and symmetric algorithms
JWS Sign & Verify
Create and verify JSON Web Signatures (JWS) with HMAC, RSA, and ECDSA algorithms
JWT Decoder
Decode and inspect JSON Web Tokens — header, payload and signature
Data Converters10 tools
Convert between data formats: XML, JSON, CSV, YAML, XSLT
CSV to JSON Converter
Convert CSV data to JSON arrays or objects with header detection
CSV to XML Converter
Convert CSV data to XML format with customizable element names
JSON to CSV Converter
Convert JSON arrays and objects to CSV with custom delimiters and headers
JSON to XML Converter
Convert JSON objects to well-formed XML documents
Mock Data Generator
Generate fake but realistic data (names, emails, dates, lorem) as JSON, CSV or SQL inserts
TOML Converter
Convert between TOML, JSON and YAML — useful for migrating between config-file formats
TOON Converter
Convert JSON or XML to TOON (Token-Oriented Object Notation) — a compact, LLM-friendly format with live character savings
XML to JSON Converter
Convert XML documents to JSON format with attribute handling options
XSLT Transformer
Transform XML documents using XSLT stylesheets
YAML ↔ JSON Converter
Convert between YAML and JSON formats bidirectionally
Formatters8 tools
Beautify and minify code in JSON, XML, SQL, HTML, JS, and CSS
CSS Formatter
Beautify and minify CSS stylesheets with vendor prefix handling
HTML Formatter
Format, prettify and beautify HTML documents with customizable indentation
JavaScript Formatter
Beautify and minify JavaScript code with configurable options
JSON Formatter
Prettify, minify and validate JSON with syntax highlighting and tree view
Mermaid Formatter
Format, validate and beautify Mermaid diagrams and flowcharts
SQL Formatter
Format and beautify SQL queries
XML Formatter
Format, prettify and validate XML documents
YAML Formatter
Format, validate and beautify YAML documents with indent control
Fun & Games7 tools
Coin toss, dice rolls, timers, and other playful utilities
Coin Toss
Flip a fair virtual coin with 3D animation — heads or tails with flip statistics
Dice Roll
Roll polyhedral dice (d4–d20) with advantage/disadvantage mode for TTRPGs and probability experiments
Magic 8-Ball
Ask a yes/no question and let the classic Magic 8-Ball reveal your fate with all 20 original responses
Spin the Wheel
Animated prize wheel — add up to 12 custom options and spin to pick a random winner
Stopwatch
High-precision stopwatch with lap splits, best/worst lap highlighting, and millisecond accuracy — runs entirely in your browser
Timer
Countdown timer with presets, custom duration, audio chime, and Pomodoro support — runs entirely in your browser
Typing Speed Test
Measure your WPM with real-time character highlighting, accuracy tracking, and timed test modes
Generators10 tools
Create UUIDs, passwords, code stubs, QR codes, and more
Color Contrast Checker
Check WCAG contrast ratios between foreground and background colors
Credit Card Generator
Generate Luhn-valid test card numbers for every major brand with CVV and expiry
Java POJO Generator
Generate Java classes, records, interfaces from JSON/XML or convert Java to JSON/XML
JSON to TypeScript
Convert JSON objects to TypeScript interfaces and types automatically
Lorem Ipsum Generator
Generate placeholder text in paragraphs, sentences, or words
Markdown Table Generator
Create and edit markdown tables with a visual spreadsheet interface
Password Generator
Generate secure random passwords with customizable length and character sets
QR Code Generator
Generate QR codes from text, URLs, or data with customization options
Slug Generator
Generate URL-safe slugs from any text — supports unicode, custom separators
UUID Generator
Generate random UUIDs (v4) in bulk
Image & Media6 tools
Compress, optimise, inspect and convert images in your browser
Color Palette Extractor
Extract the dominant colours from any image — outputs HEX, RGB and HSL values ready to copy
EXIF Viewer
Inspect EXIF, GPS and IPTC metadata embedded in JPEG and TIFF photos — entirely on-device
Favicon Generator
Generate a full favicon set (16, 32, 48, 192, 512, apple-touch-icon) from a single source image
Image Compressor
Compress JPEG, PNG and WebP in your browser with quality slider and live before/after preview
Image Resizer
Resize JPEG, PNG and WebP by pixels, percentage, or preset — fit, fill or stretch, all in your browser
SVG Optimizer
Shrink SVG markup by stripping editor metadata, collapsing transforms and rounding numeric precision
Network7 tools
IP, subnet, MAC, DNS, CORS, WebSocket and webhook tooling
CORS Tester
Send preflight and actual requests from any origin, watch CORS headers and explain failures in plain English
DNS Lookup
Resolve A, AAAA, CNAME, MX, TXT, NS, SOA records for any hostname using public DNS-over-HTTPS resolvers
IP Address Tools
Validate, parse, and convert IPv4/IPv6 addresses with detailed information
MAC Address Tools
Validate, format, and generate MAC addresses with vendor lookup
Subnet Calculator
Calculate subnet masks, network ranges, CIDR notation, and available hosts
Webhook Receiver
Generate a unique inbound URL, capture incoming HTTP requests in real time, and inspect headers and body
WebSocket Tester
Connect to ws:// and wss:// endpoints, send messages, watch frames stream in with timestamped history
Text & Utilities12 tools
Text manipulation, time, color, number bases, and productivity
Color Picker & Converter
Pick colors and convert between HEX, RGB, HSL formats
Cron Expression Parser
Parse, validate and explain cron expressions with next run times
Markdown Preview
Write Markdown and see a live rendered preview side by side
Mermaid Viewer
Render and preview Mermaid diagrams with live editing, theme support, and SVG export
Number Base Converter
Convert numbers between decimal, binary, octal and hexadecimal
Personal Todo List
Production-grade task manager with IndexedDB storage, categories, archive, trash, import/export, subtasks, and more
Rich Text Editor
WYSIWYG document editor with full formatting (bold, headings, lists, links, colors), multiple documents, local save, source view, and export
Sticky Notes
Create, organize, and persist colorful sticky notes in your browser — pin, color-code, search, and delete with full localStorage memory
String Case Converter
Convert text between camelCase, snake_case, PascalCase, kebab-case and more
Text Manipulation Tools
Sort lines, remove duplicates, trim whitespace, count words and more
Timestamp Converter
Convert between Unix timestamps and human-readable dates
Unix Permissions Calculator
Calculate chmod numeric values and understand file permission bits
Validators8 tools
Validate syntax, schemas, and patterns in your data
Credit Card Validator
Validate and generate test credit card numbers with Luhn algorithm
Email Validator
Validate email addresses with RFC-compliant syntax and disposable detection
HTML Validator
Validate HTML markup for errors and best practices
JSON Validator
Validate JSON syntax with detailed error messages and line numbers
Regex Tester
Test regular expressions with live matching and group highlighting
XML Validator
Validate XML syntax and well-formedness with error highlighting
XPath Tester
Test and evaluate XPath expressions against XML documents
XSD Schema Validator
Validate XML documents against XSD schemas with detailed error reporting
Reference6 tools
Lookup guides for HTTP codes, MIME types, ports, and RFCs
HTTP Status Codes Reference
Complete reference guide for HTTP status codes (1xx-5xx) with detailed descriptions, use cases, common scenarios, and best practices for REST API development
IP Ranges Reference
Reference guide for private, reserved, and special-use IP address ranges
MIME Types Reference
Comprehensive searchable database of MIME types (Content-Types) with file extensions, categories, and usage examples for web development, file uploads, and HTTP headers
Model & Pricing Comparison
Compare context windows, output limits and per-token pricing across major LLM providers
Port Number Reference
Comprehensive reference of common network ports, protocols, and services
RFC Standards Reference
Comprehensive reference for important RFC standards including JWT, JWE, JWS, OAuth, HTTP, TLS, and other security and web protocols

113 tools · all client-side · no account required · open source