Free Online Tools
Fast, free, and privacy-friendly tools that work right in your browser. No signup, no data collection.
DevToolKit is a suite of free browser-based developer tools built for programmers, DevOps engineers, and backend developers. From TOML-to-YAML conversion and SQL-to-MongoDB translation to cron expression generation and Nginx config scaffolding — every tool runs entirely in your browser with zero server uploads. Your code and configs stay private, always.
Whether you need to generate environment files, calculate chmod permissions, create HMAC hashes, or convert SVG to JSX components, our tools are designed to be fast, accurate, and completely free with no signup required.
Converters
Convert between formats and languages
JSON to Zod
Paste JSON → get a ready-to-use Zod TypeScript schema in seconds. Handles nested objects, arrays, and nullables. Perfect for Next.js and tRPC. 100% browser-based.
TOML to YAML
Paste TOML → get clean YAML output instantly. Supports nested tables, arrays, and inline values. Ideal for Cargo-to-K8s migrations. Free, no signup, runs in your browser.
YAML to TOML
Paste YAML → get valid TOML output in one click. Handles nested objects, arrays, and inline tables. Great for pyproject.toml and Cargo. Browser-based, no signup required.
SVG to JSX
Paste SVG → get a ready-to-use React JSX component with camelCase props and TypeScript types. Handles gradients, filters, and masks. 100% client-side, no data uploaded.
SQL to MongoDB
Paste a SQL query → get the MongoDB Node.js equivalent. Supports SELECT, INSERT, UPDATE, DELETE with WHERE, ORDER BY, and LIMIT. Free browser tool, no signup needed.
JSON to Protobuf
Paste JSON → get a ready-to-use Protocol Buffers (.proto) message definition instantly. Auto-detects field types, handles nested objects and arrays. Free, browser-based, no signup.
Properties to YAML
Paste Java .properties → get clean YAML output instantly. Handles nested keys (server.port → server:\n port:), comments, and special characters. Also supports YAML to Properties reverse conversion.
URL Encoder/Decoder
Free URL encoder and decoder. Encode special characters for URLs or decode percent-encoded strings. Supports full URL and component encoding.
HTML Entity Encoder
Free HTML entity encoder and decoder. Convert special characters to HTML entities and back. Supports named and numeric entities.
Unix Timestamp Converter
Free Unix timestamp converter. Convert between Unix epoch timestamps and human-readable dates. Get current timestamp. Support milliseconds.
CSV to JSON
Convert CSV data to a JSON array of objects. Auto-detects headers, handles quoted fields and custom delimiters. Preview, copy, or download results. Free, browser-based.
JSON to TypeScript
Paste JSON → get TypeScript interfaces instantly. Handles nested objects, arrays, optional fields, and union types. Perfect for typing API responses. 100% browser-based.
TypeScript Interface Generator
Instantly convert JSON to TypeScript interface definitions. Supports nested objects, arrays, and optional fields. Free json to typescript interface tool — no signup needed.
Generators
Generate configs, code, and boilerplate
Cron Expression Generator
Pick options → get a valid cron expression with a human-readable description. Presets for hourly, daily, weekly, and monthly. Works with GitHub Actions and K8s CronJobs.
Env File Generator
Choose a framework → get a complete .env template with documented variables. Covers Next.js, Django, Laravel, Express, and Rails. Free, editable, browser-based.
Nginx Config Generator
Fill in options → get a complete Nginx server block with SSL, gzip, and reverse proxy support. Copy-paste ready for /etc/nginx/. Free online tool, no signup required.
Docker Compose Generator
Build docker-compose.yml visually: add services, ports, volumes, env vars, and dependencies. Pre-built templates for MERN, LAMP, WordPress, Redis+Node, PostgreSQL+Django. Free, browser-based.
MD5 Hash Generator
Free MD5 hash generator. Generate MD5 checksums from any text or string instantly. Secure client-side hashing.
SHA-256 Hash Generator
Free SHA-256 hash generator. Create SHA-256 hashes from text securely in your browser. No data sent to server.
SHA-1 Hash Generator
Free SHA-1 hash generator online. Generate SHA-1 hashes from any text string instantly in your browser.
SHA-512 Hash Generator
Free SHA-512 hash generator. Create SHA-512 hashes from text with this secure browser-based tool. No server processing.
Bcrypt Hash Generator
Free bcrypt hash generator. Generate bcrypt password hashes with configurable salt rounds. All processing in your browser.
Git Commit Message Generator
Free git commit message generator following Conventional Commits spec. Pick type, add scope & description — get a perfect commit message instantly. No signup needed.
Lorem Ipsum Generator
Generate Lorem Ipsum placeholder text instantly. Choose paragraphs, word count, format (Plain/HTML/Markdown), and classic start. Free, no signup, all client-side.
Robots.txt Generator
Generate a robots.txt file instantly. Configure user-agents, allow/disallow paths, sitemap URL, and choose from preset templates. Free, no signup needed.
.htaccess Generator
Generate Apache .htaccess rules for redirects, security, HTTPS, GZIP, and caching. Visual tabbed interface — no server config knowledge needed. Free, no signup.
Formatters
Format and beautify code
SQL Formatter
Paste messy SQL → get properly indented, uppercase-keyword output instantly. Supports SELECT, JOIN, subqueries, and DDL statements. Works with MySQL, PostgreSQL, and more.
CSS Minifier
Paste CSS → get minified output with size-reduction stats. Strips comments, whitespace, and redundant semicolons. Typical savings 15-40%. Fast, private, browser-based.
HTML Prettifier
Paste minified or messy HTML → get clean, indented output in one click. Handles nested tags, void elements, and inline styles. Configurable indent size. 100% browser-based.
JSON Formatter
Free JSON formatter and beautifier. Paste JSON → get perfectly indented, syntax-highlighted output. Validate, minify, and format JSON with customizable indentation. 100% browser-based.
XML Formatter
Free XML formatter and beautifier. Paste XML → get perfectly indented output. Validate, minify, and format XML with customizable indentation. Works offline in your browser.
YAML Formatter
Format and beautify YAML with customizable indentation. Validates syntax, highlights errors with line numbers. Supports 2/4-space indent. Free, browser-based YAML pretty printer.
HTML Minifier
Free HTML minifier tool. Remove whitespace, comments, and redundant attributes from HTML to reduce file size. See compression stats. 100% browser-based, no data uploaded.
JavaScript Minifier
Free JavaScript minifier. Remove whitespace, comments, and shorten code to reduce JS file size. See compression stats. Works offline in your browser — no data uploaded.
SQL Beautifier
Free SQL beautifier tool. Format SQL with uppercase keywords, customizable indentation, and aligned clauses. Supports SELECT, INSERT, UPDATE, DELETE, and more. 100% browser-based.
Utilities
Encode, decode, hash, and calculate
Chmod Calculator
Set Unix permissions with checkboxes → get numeric (755) and symbolic (rwxr-xr-x) output instantly. Includes umask mode. Works offline in your browser — no signup needed.
HMAC Generator
Enter message + secret key → get HMAC in hex and base64 instantly. Supports SHA-256, SHA-384, and SHA-512. Verify Stripe and GitHub webhook signatures. Runs 100% in-browser.
JWT Decoder
Free JWT decoder and parser. Decode JSON Web Tokens to inspect header, payload, and signature. Verify token expiration and claims.
Regex Tester
Free online regex tester. Test regular expressions against sample text with real-time match highlighting. Supports JavaScript regex syntax.
Base64 Image Encoder
Free base64 image encoder. Convert PNG, JPG, SVG, GIF, and WebP images to base64 data URI strings. Copy CSS background or HTML img tag. 100% browser-based.
Color Picker
Free online color picker tool. Pick any color and get HEX, RGB, HSL, and CSS values instantly. Generate color palettes and copy color codes. Works in your browser.
JSON Validator
Validate JSON syntax instantly. Get detailed error messages with exact line and column numbers. Highlights common mistakes like trailing commas and missing quotes. Free, browser-based.
JSON Schema Validator
Validate JSON data against a JSON Schema. See all validation errors at once with paths and details. Supports Draft-07 features. Free, browser-based, no signup.
JSON Diff
Free JSON diff tool. Paste two JSON objects and instantly see additions, deletions, and changes highlighted. Deep comparison of nested objects and arrays. 100% browser-based.
Crontab Guru
Free cron expression parser. Paste a cron expression and get a human-readable explanation, next run times, and validation. Supports standard 5-field crontab syntax. 100% browser-based.
More Free Tools
Explore specialized tools from our network — all free, browser-based, and privacy-first.