Your everyday developer workspace.
Format JSON. Test APIs. Inspect tokens. Work with databases. The tools you reach for all day, together in one workspace.
Local processing by default No account required
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Every tool shows its processing boundary before you use it.
- Browser tools
- Formatting, decoding and other local transformations run on your device.
- Network tools
- API and lookup tools contact the services shown in the tool when you run them. Native database and storage connections need the desktop app or local runtime.
- Saved work
- Projects and preferences stay in this browser. Use the passphrase-protected vaults for credentials and private files, and export backups for safekeeping.
Find your next everyday tool.
147 tools. 15 categories. One place to get started.
147 tools for everyday development.
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147 matching tools
Artificial Intelligence 6
Protocol inspectors connect to your endpoints; token and dataset tools process locally
A2A Inspector
Inspect Agent-to-Agent cards, check selected fields, exchange messages and view raw JSON-RPC 2.0 responses
Network features · view data disclosureAgent 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
Local processingFine-Tuning Dataset Validator
Validate JSONL fine-tuning datasets against OpenAI or Anthropic message schemas — entirely in your browser
Local processingLLM Token Counter
Count tokens and estimate context-window usage across GPT, Claude, and open models
Connects directly from your browserMCP Inspector
Connect to any Model Context Protocol server, browse tools, and call them interactively over SSE or HTTP
Network features · view data disclosureSemantic Search Playground
Real embedding-based search over your own text, computed entirely in your browser — no server, no API key
Network features · view data disclosureDiff & Compare 6
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
Local processingImage Diff
Pixel-perfect visual comparison: side-by-side, overlay, and difference modes with adjustable tolerance
Local processingJSON Diff
Compare two JSON documents side by side with highlighted differences
Local processingOpenAPI Contract Diff
Compare OpenAPI contracts and flag high-confidence breaking changes
Local processingText Diff
Compare any two text blocks with line-by-line diff highlighting
Local processingXML Diff
Compare two XML documents side by side with highlighted differences
Local processingAPI & Web Services 13
REST, SOAP, WSDL: build and inspect web service requests
API Request Builder
Test HTTP and gRPC APIs, run request collections and start local mock servers
Network features · view data disclosureAsyncAPI Explorer
Inspect AsyncAPI event contracts, channels, operations, servers, and messages
Local processingDocument Data Explorer
Browse and query MongoDB, Firestore and Elasticsearch with encrypted saved connections and type-aware exports
Network features · view data disclosureGraphQL Schema & Operation Explorer
Validate GraphQL operations against an SDL schema locally
Local processingJSONPath Tester
Query JSON with JSONPath or JMESPath, with examples and precision-aware input handling
Local processingOAuth / OIDC & PKCE Playground
Inspect OAuth discovery metadata and generate local PKCE S256 values
Local processingRedis Browser
Scan keys, inspect typed values and run bounded Redis commands with encrypted saved connections
Network features · view data disclosureS3 Storage Browser
Browse S3-compatible buckets, prefixes and object metadata; transfer files with encrypted saved connections
Network features · view data disclosureSOAP Client
Test SOAP web services by sending requests and viewing responses
Network features · view data disclosureSQL Database Workspace
Query SQLite files locally and connect to PostgreSQL, MySQL and MariaDB with encrypted saved connections
Network features · view data disclosureSwagger / OpenAPI Viewer
Paste or upload an OpenAPI spec and get interactive API documentation
Network features · view data disclosureURL Parser
Parse and analyze URLs into components: protocol, host, path, query, fragment
Local processingWSDL Parser
Parse and visualize WSDL files, view services, ports, operations, and messages
Network features · view data disclosureEncoding & Decoding 7
Encode and decode text: Base64, URL, HTML, Unicode, Gzip
Base64 Encode / Decode
Encode and decode Base64 strings instantly
Local processingGzip Compress / Decompress
Compress and decompress text using Gzip with Base64 encoding
Local processingHex Encoder / Decoder
Encode text to hexadecimal and decode hex strings back to text (UTF-8)
Local processingHTML Entities Encoder
Encode and decode HTML entities and special characters
Local processingString Escape / Unescape
Escape and unescape strings for JSON, XML, HTML, JavaScript, SQL, and CSV
Local processingUnicode Converter
Convert text to/from Unicode escape sequences, code points, and UTF-8 hex
Local processingURL Encode / Decode
Encode and decode URL components
Local processingCertificates & Keys 8
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
Local processingCertificate Chain & SSL
Inspect live certificate chains through a disclosed server connection, or analyze pasted certificates locally
Uses the mydevtools serverCertificate Inspector
Decode, fingerprint and convert X.509 certificates in PEM or DER; inspect live certificates from permitted public hosts.
Network features · view data disclosureJava KeyStore (JKS) Tool
Build PKCS#12 files from PEM and prepare Java keytool commands for JKS workflows
Local processingKey Pair Generator
Generate RSA, ECDSA, and Ed25519 key pairs in PEM and other formats
Local processingPKCS#12 / PFX Tool
Create, extract, and convert PKCS#12/PFX files containing certificates and private keys
Local processingSSH Key Generator
Generate local RSA, ECDSA and Ed25519 OpenSSH keys with SHA-256 fingerprints
Local processingWebAuthn / Passkey Playground
Inspect WebAuthn credential response metadata locally
Local processingCryptography 12
Hashing, HMAC, JWT, JWS, JWE, and JWK key generation
AES Encrypt & Decrypt
Encrypt and decrypt CryptoJS-compatible AES-CBC passphrase text locally
Local processingBCrypt Hash & Verify
Generate BCrypt hashes for passwords and verify passwords against existing hashes
Local processingCredential Vault
Encrypt passwords, API keys, environment variables and saved connections locally
Local processingHash Generator
Generate MD5, SHA-1, SHA-2, Keccak and RIPEMD-160 text hashes
Local processingHMAC Generator
Generate HMAC signatures using SHA-1, SHA-256, SHA-384, SHA-512 algorithms
Local processingJWE Encrypt & Decrypt
Encrypt and decrypt data using JSON Web Encryption (JWE) with RSA and AES algorithms
Local processingJWK Generator
Generate JSON Web Keys (JWK) for RSA, EC, and symmetric algorithms
Local processingJWS Sign & Verify
Create and verify JSON Web Signatures (JWS) with HMAC, RSA, and ECDSA algorithms
Local processingJWT Decoder
Decode and inspect JSON Web Tokens — header, payload and signature
Local processingSecure Files
Encrypt file contents and metadata locally with portable backups
Local processingTOTP Generator
Generate local RFC 6238 authenticator codes with configurable time-step and public test vectors
Local processingWebhook Signature Debugger
Verify GitHub, Stripe, Slack, and HMAC webhook signatures locally
Local processingData Converters 11
Convert between data formats: XML, JSON, CSV, YAML, XSLT
CSV to JSON Converter
Convert CSV data to JSON arrays or objects with header detection
Local processingCSV to XML Converter
Convert CSV data to XML format with customizable element names
Local processingJSON / YAML / TOML / XML Converter
Convert in all twelve directions between JSON, YAML, TOML and XML with explicit mapping limits
Local processingJSON to CSV Converter
Convert JSON arrays and objects to CSV with custom delimiters and headers
Local processingJSON to XML Converter
Convert JSON objects to well-formed XML documents
Local processingMock Data Generator
Generate fake but realistic data (names, emails, dates, lorem) as JSON, CSV or SQL inserts
Local processingScientific Unit Converter
Convert physical, electrical, thermal and engineering quantities with explicit unit definitions
Local processingTOON Converter
Convert JSON or XML to TOON (Token-Oriented Object Notation) — a compact, LLM-friendly format with live character savings
Local processingXML to JSON Converter
Convert XML documents to JSON format with attribute handling options
Local processingXSLT Transformer
Transform XML documents using XSLT stylesheets
Local processingYAML ↔ JSON Converter
Convert between YAML and JSON formats bidirectionally
Local processingFormatters 8
Beautify and minify code in JSON, XML, SQL, HTML, JS, and CSS
CSS Formatter
Beautify and minify CSS stylesheets with vendor prefix handling
Local processingHTML Formatter
Format, prettify and beautify HTML documents with customizable indentation
Local processingJavaScript Formatter
Beautify and minify JavaScript code with configurable options
Local processingJSON Formatter
Prettify, minify and validate JSON with syntax highlighting and tree view
Local processingMermaid Formatter
Format, validate and beautify Mermaid diagrams and flowcharts
Local processingSQL Formatter
Format and beautify SQL queries
Local processingXML Formatter
Format, prettify and validate XML documents
Local processingYAML Formatter
Format, validate and beautify YAML documents with indent control
Local processingFun & Games 7
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
Local processingDice Roll
Roll polyhedral dice (d4–d20) with advantage/disadvantage mode for TTRPGs and probability experiments
Local processingMagic 8-Ball
Ask a yes/no question and let the classic Magic 8-Ball reveal your fate with all 20 original responses
Local processingSpin the Wheel
Animated prize wheel — add up to 12 custom options and spin to pick a random winner
Local processingStopwatch
Browser stopwatch with lap splits, best/worst lap highlighting and a millisecond display; timing depends on browser scheduling
Local processingTimer
Countdown timer with presets, custom duration, audio chime, and Pomodoro support — runs entirely in your browser
Local processingTyping Speed Test
Measure your WPM with real-time character highlighting, accuracy tracking, and timed test modes
Local processingGenerators 14
Create UUIDs, passwords, code stubs, QR codes, and more
.gitignore Generator
Combine stack, editor and operating-system ignore patterns with custom overrides
Local processingColor Contrast Checker
Check WCAG contrast ratios between foreground and background colors
Local processingCredit Card Generator
Generate synthetic Luhn-valid card fixtures with security codes and expiry dates
Local processingCSS Visual Builders
Design multi-layer shadows, elliptical radii, fluid typography and configurable gradients with live previews
Local processingDocker Compose Generator
Configure a local stack with service starters, ports, named volumes, environment variables and dependencies
Local processingJava POJO Generator
Generate Java classes, records, interfaces from JSON/XML or convert Java to JSON/XML
Local processingJSON Schema & Model Generator
Infer JSON Schema from sample data and generate typed models for nine languages
Local processingJSON to TypeScript
Convert JSON objects to TypeScript interfaces and types automatically
Local processingLorem Ipsum Generator
Generate placeholder text in paragraphs, sentences, or words
Local processingMarkdown Table Generator
Create and edit markdown tables with a visual spreadsheet interface
Local processingPassword Generator
Generate secure random passwords with customizable length and character sets
Local processingQR Code Generator
Generate QR codes from text, URLs, or data with customization options
Local processingSlug Generator
Generate URL-safe slugs from any text — supports unicode, custom separators
Local processingUUID Generator & Inspector
Generate UUIDv3/v5 namespace IDs, random UUIDv4, time-ordered UUIDv7 and ULIDs; inspect versions and timestamps
Local processingImage & Media 7
Compress, optimise, inspect and convert images in your browser
Code Screenshot
Create syntax-highlighted code images with themes, backgrounds, window controls and real PNG export
Local processingColor Palette Extractor
Extract the dominant colours from any image — outputs HEX, RGB and HSL values ready to copy
Local processingFavicon, ICO & Maskable Generator
Generate PNG favicons, a six-size ICO, a safe-zone maskable icon and matching manifest in one ZIP
Local processingImage Compressor
Compress JPEG, PNG and WebP in your browser with quality slider and live before/after preview
Local processingImage Metadata Viewer & Remover
Inspect image metadata, remove JPEG/PNG/WebP metadata without re-encoding, and convert supported formats locally
Local processingImage Resizer
Resize JPEG, PNG and WebP by pixels, percentage, or preset — fit, fill or stretch, all in your browser
Local processingSVG Optimizer
Shrink SVG markup by stripping editor metadata, collapsing transforms and rounding numeric precision
Local processingNetwork 11
IP, subnet, MAC, DNS, CORS, WebSocket and webhook tooling
CORS Tester
Test requests from this browser origin, inspect exposed CORS headers and review possible causes of opaque failures
Network features · view data disclosureDNS Lookup
Resolve A, AAAA, CNAME, MX, TXT, NS, SOA records for any hostname using public DNS-over-HTTPS resolvers
Connects directly from your browserDocker Compose Analyzer
Review Compose YAML services, ports, networks, volumes, and hygiene
Local processingDomain & IP Registration (RDAP)
Look up public domain/IP registration, registrars, events, statuses and nameservers
Uses the mydevtools serverIP Address Tools
Validate, parse, and convert IPv4/IPv6 addresses with detailed information
Local processingMAC Address Tools
Validate, format, and generate MAC addresses with vendor lookup
Local processingSecurity Headers & CSP Analyzer
Audit pasted HTTP response headers and Content Security Policy rules
Local processingSubnet Calculator
Calculate subnet masks, network ranges, CIDR notation, and available hosts
Local processingTrace Context Inspector
Inspect and generate W3C traceparent and tracestate headers
Local processingWebhook Receiver
Generate a unique inbound URL, capture incoming HTTP requests in real time, and inspect headers and body
Uses the mydevtools serverWebSocket Tester
Connect to ws:// and wss:// endpoints, send messages, watch frames stream in with timestamped history
Connects directly from your browserText & Utilities 22
Text manipulation, time, color, number bases, and productivity
Code Snippets
Save, search, format and copy project code snippets with syntax highlighting
Local processingColor Picker & Converter
Pick colors and convert between HEX, RGB, HSL formats
Local processingCron Expression Parser
Parse, validate and explain cron expressions with next run times
Local processingHAR & Log Redactor
Redact credentials and custom fields from HAR, JSON, and logs locally
Local processingJSON Graph Visualizer
Explore JSON with pan, zoom, branch collapse, path search, array tables and SVG/PNG export
Local processingKeyboard Event Inspector
Inspect key, code, modifiers, locations and browser keyboard event history
Local processingMarkdown Preview
Write Markdown and see a live rendered preview side by side
Local processingMermaid Viewer
Render and preview Mermaid diagrams with live editing, theme support, and SVG export
Local processingNumber Base Converter
Convert exact signed integers between any bases from 2 through 36
Local processingPersonal Todo List
Production-grade task manager with IndexedDB storage, categories, archive, trash, import/export, subtasks, and more
Local processingProject Workspaces
Keep project notes, snippets, workflows and connections separate
Local processingResource Bookmarks
Organize project documentation, repositories and external links
Local processingRich Text Editor
WYSIWYG document editor with full formatting (bold, headings, lists, links, colors), multiple documents, local save, source view, and export
Local processingSaved Workflows
Chain local tools and save repeatable transformations with settings and fixtures
Local processingSticky Notes
Create, organize, and persist colorful sticky notes in your browser — pin, color-code, search, and delete with full localStorage memory
Local processingString Case Converter
Convert text between camelCase, snake_case, PascalCase, kebab-case and more
Local processingText Manipulation Tools
Sort lines, remove duplicates, trim whitespace, count words and more
Local processingTimestamp Converter
Convert between Unix timestamps and human-readable dates
Local processingTimezone Planner
Compare meeting times, UTC offsets, date shifts and working hours across IANA timezones
Local processingTool Tabs
Keep multiple tools open, switch and reorder tabs without losing input
Local processingUnix Permissions Calculator
Calculate chmod numeric values and understand file permission bits
Local processingUser-Agent & Client Hints Parser
Inspect reported browser, OS, engine, device and CPU details locally
Local processingValidators 9
Validate syntax, schemas, and patterns in your data
Credit Card Validator
Validate and generate test credit card numbers with Luhn algorithm
Local processingEmail Validator
Inspect email syntax and disposable-domain signals
Connects directly from your browserHTML Validator
Validate HTML markup for errors and best practices
Local processingJSON Schema Workbench
Validate JSON and YAML instances against local JSON Schema rules
Local processingJSON Validator
Validate JSON syntax with detailed error messages and line numbers
Local processingRegex Tester
Test regular expressions with live matching and group highlighting
Local processingXML Validator
Validate XML syntax and well-formedness with error highlighting
Local processingXPath Tester
Test and evaluate XPath expressions against XML documents
Local processingXSD Schema Validator
Check XML well-formedness, root names and namespaces alongside a parsed XSD
Local processingReference 6
Lookup guides for HTTP codes, MIME types, ports, and RFCs
HTTP Status Codes Reference
Selected HTTP status codes with explanations, examples and primary sources
Local processingIP Ranges Reference
Reference guide for private, reserved, and special-use IP address ranges
Local processingMIME 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
Local processingModel & Pricing Comparison
Compare context windows, output limits and per-token pricing across major LLM providers
Local processingPort Number Reference
Local reference of selected common ports, protocols and service conventions
Local processingRFC Standards Reference
Selected RFCs with explanations, maturity levels and replacement links
Local processing