The Ultimate Toolbox for Modern Developers
Format JSON, generate UUIDs, decode JWTs, test regex, inspect DNS records, check SSL certificates, and convert data formats instantly in your browser.
Most Popular Developer Tools
Essential everyday utilities for developers
- Client
JSON Formatter & Validator
Format, validate, beautify, and minify JSON with tree viewer and syntax highlighting.
Open Tool - Client
UUID / GUID Generator
Generate cryptographically random UUID v4, time-based v1, and modern v7 identifiers in bulk.
Open Tool - Client
Base64 Encoder & Decoder
Encode and decode plain text and files to/from Base64 with UTF-8 and URL-safe support.
Open Tool - Client
Secure Password Generator
Generate strong, unhackable passwords using browser-native cryptographic randomness.
Open Tool - Client
Unix Timestamp Converter
Convert Unix epoch timestamps (seconds & milliseconds) to human-readable date and time formats.
Open Tool - Client
Regular Expression (Regex) Tester
Test and debug regular expressions in real-time with visual match highlighting and capture groups.
Open Tool - Client
Text & Code Diff Checker
Compare two text files or code snippets side-by-side with line-by-line and character diff highlighting.
Open Tool - Client
Mermaid Diagram Live Preview & Editor
Interactive live Mermaid.js diagram editor and preview with SVG/PNG/MMD download, rich template library, zoom controls, and error diagnostics.
Open Tool
Formatters & Validators
Format, beautify, minify and validate code and data structures
- JSON Formatter & Validator
Format, validate, beautify, and minify JSON with tree viewer and syntax highlighting.
- SQL Query Formatter
Beautify, format, and indent complex SQL queries for PostgreSQL, MySQL, SQLite, and Transact-SQL.
- HTML Formatter & Minifier
Beautify, indent, and minify HTML markup with tag preservation and attribute alignment.
- CSS Formatter & Minifier
Beautify and minify CSS stylesheets with rule grouping and property sorting.
- XML Formatter & XML ↔ JSON Converter
Format, beautify, minify XML documents and convert seamlessly between XML and JSON formats.
Data Converters
Convert data across multiple formats (JSON, YAML, CSV, XML, timestamps)
- Unix Timestamp Converter
Convert Unix epoch timestamps (seconds & milliseconds) to human-readable date and time formats.
- Color Format Converter
Convert colors seamlessly between HEX, RGB, HSL, HSV, and CMYK formats with visual color picker.
- JSON ↔ YAML Converter
Convert seamlessly between JSON and YAML formats with syntax validation and indentation controls.
- JSON ↔ CSV Converter
Convert JSON arrays to CSV spreadsheets and parse CSV files into structured JSON objects.
- Number Base Converter
Convert numbers across Decimal, Binary, Hexadecimal, and Octal formats with bitwise representations.
- Data Size & Byte Unit Converter
Convert data storage units across Bytes, KB, MB, GB, TB, PB with Decimal (1000) and Binary (1024) standards.
- cURL Command to Code Converter
Convert raw cURL terminal commands into JavaScript Fetch, Python Requests, Go HTTP, and Axios code snippets.
- JSON to Code & Type Converter
Convert JSON payloads into TypeScript interfaces, Go structs, Python Pydantic models, Rust serde types, and Java records.
- HTML to React JSX Converter
Convert standard HTML snippets into clean React JSX code with attribute mapping, style parsing, and self-closing tags.
Encoders & Decoders
Encode and decode Base64, URLs, HTML entities, and JWTs
- Base64 Encoder & Decoder
Encode and decode plain text and files to/from Base64 with UTF-8 and URL-safe support.
- URL Encoder & Decoder
Encode and decode query strings and special characters for safe HTTP URL transmission.
- HTML Entity Encoder & Decoder
Encode special characters into HTML entities (<, >, &) and decode entities back to plain text.
- URL Parser & Query String Builder
Deconstruct URLs into protocol, hostname, port, pathname, hash, and edit query parameters in an interactive live table.
Generators
Generate UUIDs, secure passwords, dummy text, QR codes, and slugs
- UUID / GUID Generator
Generate cryptographically random UUID v4, time-based v1, and modern v7 identifiers in bulk.
- Secure Password Generator
Generate strong, unhackable passwords using browser-native cryptographic randomness.
- QR Code Generator
Generate high-resolution custom QR codes for URLs, WiFi credentials, plain text, and emails with PNG/SVG download.
- Lorem Ipsum Dummy Text Generator
Generate placeholder dummy text by paragraphs, sentences, words, or lists for UI design and mockups.
- URL Slug Generator
Convert any text, title, or Vietnamese string into a clean, SEO-friendly URL slug.
Cryptography & Hashes
Compute MD5, SHA, Bcrypt, HMAC, and cryptographic checksums
Network & Web Tools
DNS queries, SSL certificate analysis, HTTP header inspection and IP lookup
- DNS Record Lookup
Query domain DNS records (A, AAAA, CNAME, MX, TXT, NS) with fast Go backend resolver.
- SSL / TLS Certificate Checker
Inspect SSL/TLS certificate validity, expiration date, issuer, cipher suite, and TLS protocol version.
- HTTP Header & Response Inspector
Inspect HTTP response headers, status codes, latency, and security headers of any URL.
- My IP & Reverse DNS Lookup
Find your public IP address, detect IPv4/IPv6, and perform forward and reverse DNS lookups.
- IPv4 Subnet & CIDR Calculator
Calculate IPv4 subnets, network address, broadcast address, usable host ranges, and wildcard masks from CIDR notation.
- User-Agent Parser & Device Inspector
Analyze User-Agent strings to detect browser name, version, rendering engine, operating system, and device type.
Text & String Tools
Diff comparison, regex tester, string case converter, markdown live preview
- Regular Expression (Regex) Tester
Test and debug regular expressions in real-time with visual match highlighting and capture groups.
- Text & Code Diff Checker
Compare two text files or code snippets side-by-side with line-by-line and character diff highlighting.
- Markdown Live Editor & Preview
Live markdown editor with synchronized split-screen preview, GitHub Flavored Markdown (GFM) support, and HTML export.
- Mermaid Diagram Live Preview & Editor
Interactive live Mermaid.js diagram editor and preview with SVG/PNG/MMD download, rich template library, zoom controls, and error diagnostics.
- String Case Converter
Convert text between camelCase, snake_case, kebab-case, PascalCase, CONSTANT_CASE, and Title Case.
Developer References
HTTP status codes, MIME types, Cron expressions, and standard references
- HTTP Status Codes Reference
Comprehensive, searchable cheat sheet of all standard HTTP response status codes with detailed explanations.
- Cron Expression Builder & Explainer
Build and translate standard 5-part and 6-part Cron expressions into human-readable schedules with next execution times.
- MIME Types & Content-Type Reference
Searchable dictionary of standard MIME types, HTTP Content-Type headers, and associated file extensions.
- Linux Chmod Permissions Calculator
Interactive Linux chmod calculator with visual checkboxes for Owner, Group, Others, octal numbers (755, 644), and symbolic modes.
Why Developers Choose DevToolkit?
Built with privacy, performance, and developer experience at its core
Zero Data Leakage
All text formatting, parsing, encoding, and regex testing is executed 100% client-side inside your browser. Your sensitive code, tokens, and payloads never touch our servers.
Lightning Fast & Ad-Friendly
Built on Next.js and powered by a Go microservice for heavy network diagnostics. Ads are strictly isolated so your workflow remains uninterrupted.
All-in-One Utility Suite
From JSON formatters and UUID generators to SSL checkers, DNS resolvers, and JWT inspectors — everything a full-stack engineer needs daily in one single place.