# Free Developer Tools

> 100+ free, browser-based developer tools -- formatters, generators, converters, and validators. No signup, runs entirely in your browser.

- **Source:** DevDreaming (https://devdreaming.com)
- **Canonical URL:** https://devdreaming.com/tools

---

All tools run client-side in your browser -- your data is never uploaded. Each tool below links to its dedicated page with usage instructions.

## AI & LLM Tools

_AI-powered tools and calculators for developers working with machine learning and large language models._

- [LLM API Pricing Calculator](https://devdreaming.com/tools/llm-api-pricing-calculator) -- Calculate and compare costs for different LLM providers and models. Estimate your AI API expenses based on token usage.
- [Token Counter Visualizer](https://devdreaming.com/tools/token-counter-visualizer) -- Count tokens for various LLM models (GPT, Claude) and visualize how the model tokenizes your text.

## Text & Data Formatters

_Tools for encoding, decoding, formatting, and transforming text, JSON, and other data formats._

- [JSON Formatter Validator](https://devdreaming.com/tools/json-formatter-validator) -- Format, validate, and beautify JSON data. Minify JSON or convert between JSON and other formats.
- [Base64 Encoder Decoder](https://devdreaming.com/tools/base64-encoder-decoder) -- Encode text, strings, or files to Base64 format, or decode Base64 strings back to their original content.
- [JSON to TypeScript Interface](https://devdreaming.com/tools/json-to-typescript-interface) -- Generate deterministic TypeScript Interfaces or Types from a JSON object structure.
- [JSON to Zod Schema](https://devdreaming.com/tools/json-to-zod-schema) -- Convert JSON data into a Zod schema object for runtime validation in Next.js and tRPC projects.
- [JSON to CSV Converter](https://devdreaming.com/tools/json-to-csv) -- Convert JSON arrays of objects into a flat, readable CSV format for spreadsheet analysis.
- [SQL Formatter](https://devdreaming.com/tools/sql-query-formatter) -- Beautify and indent complex SQL queries (SELECT, INSERT, UPDATE) for better readability.
- [YAML to JSON Converter](https://devdreaming.com/tools/yaml-to-json) -- Convert YAML configuration files into JSON format, often used in DevOps and configuration management.
- [HTML Entity Encoder](https://devdreaming.com/tools/html-entity-encoder) -- Escape characters in HTML for safe display and prevent XSS attacks.
- [Markdown to HTML Converter](https://devdreaming.com/tools/markdown-to-html) -- Convert Markdown text into styled HTML code for use in web applications and blogs.
- [Text Diff Checker](https://devdreaming.com/tools/text-diff-checker) -- Compare two blocks of text or code to highlight differences, additions, and deletions.
- [String Case Converter](https://devdreaming.com/tools/string-case-converter) -- Convert text between camelCase, snake_case, PascalCase, kebab-case, and other formats.
- [Slug Generator](https://devdreaming.com/tools/url-slug-generator) -- Convert a title string into an SEO-friendly URL slug (kebab-case).
- [Word Counter](https://devdreaming.com/tools/word-character-counter) -- Real-time tool to count words, characters, and sentences in a block of text.
- [Minifier (JS/CSS)](https://devdreaming.com/tools/javascript-css-minifier) -- Reduce the file size of JavaScript and CSS code by removing whitespace and comments.
- [HTML Beautifier](https://devdreaming.com/tools/html-beautifier) -- Un-minify and format messy HTML code with proper indentation for easier debugging.
- [XML Formatter](https://devdreaming.com/tools/xml-formatter) -- Format and validate XML documents with proper indentation and error detection.
- [JSON Schema Generator](https://devdreaming.com/tools/json-schema-generator) -- Generate JSON Schema from sample JSON data automatically.
- [URL Encoder/Decoder](https://devdreaming.com/tools/url-encoder-decoder) -- Advanced URL encoding and decoding for full URLs and components.
- [Character Encoding Converter](https://devdreaming.com/tools/character-encoding-converter) -- Convert text to various character encodings including UTF-8, hex, binary, and Unicode.
- [Morse Code Translator](https://devdreaming.com/tools/morse-code-translator) -- Convert text to Morse code and vice versa with reference guide.

## Generators & Randomizers

_Generate random data, unique identifiers, secure passwords, and placeholder content for your projects._

- [UUID Generator](https://devdreaming.com/tools/uuid-generator) -- Generate random UUIDs (v4) or create UUIDs based on namespaces (v5). Copy with one click.
- [Lorem Ipsum Generator](https://devdreaming.com/tools/lorem-ipsum-generator) -- Generate placeholder text in various formats - paragraphs, sentences, or words. Perfect for mockups and prototypes.
- [Password Generator](https://devdreaming.com/tools/password-generator) -- Generate secure, random passwords with customizable length and character types.
- [Random Number Generator](https://devdreaming.com/tools/random-number-generator) -- Generate a list of unique or repeated random integers within a specified range.
- [Fake User Generator](https://devdreaming.com/tools/fake-user-data-generator) -- Generate realistic mock data (names, emails, addresses) for testing and seeding databases.
- [QR Code Generator](https://devdreaming.com/tools/qr-code-generator) -- Generate customizable QR codes for URLs, text, or any data. Download as PNG or SVG with custom colors.
- [Percentage Calculator](https://devdreaming.com/tools/percentage-calculator) -- Calculate percentages, increases, decreases, and percentage changes.
- [Roman Numeral Converter](https://devdreaming.com/tools/roman-numeral-converter) -- Convert between decimal numbers and Roman numerals (1-3999).
- [Number Base Converter](https://devdreaming.com/tools/number-base-converter) -- Convert numbers between binary, octal, decimal, and hexadecimal bases.
- [Date Calculator](https://devdreaming.com/tools/date-calculator) -- Calculate date differences, add/subtract days, and compute age from dates.

## Design & Visual Utilities

_Color pickers, palette generators, CSS visualizers, and graphics utilities for front-end development._

- [Color Picker Converter](https://devdreaming.com/tools/color-picker-converter) -- Pick colors and convert between formats (HEX, RGB, HSL). Generate color palettes for your projects.
- [Gradient Generator](https://devdreaming.com/tools/mesh-gradient-generator) -- Create beautiful, smooth mesh or linear CSS gradients with a visual editor.
- [Color Contrast Checker](https://devdreaming.com/tools/color-contrast-checker) -- Test color combinations against WCAG accessibility standards (AA/AAA).
- [Box Shadow Generator](https://devdreaming.com/tools/box-shadow-generator) -- Visually create complex CSS and Tailwind Box Shadows with multiple layers and custom properties.
- [Neumorphism Generator](https://devdreaming.com/tools/neumorphism-generator) -- Build the soft UI 'Neumorphic' effect with custom inner and outer shadow controls.
- [Glassmorphism Generator](https://devdreaming.com/tools/glassmorphism-generator) -- Generate CSS for the frosted-glass effect using backdrop-filter and transparency.
- [SVG Pattern Maker](https://devdreaming.com/tools/svg-pattern-maker) -- Generate customizable, lightweight SVG background patterns (dots, grids, waves) for landing pages.
- [SVG Optimizer](https://devdreaming.com/tools/svg-optimizer) -- Clean up and reduce the file size of SVG assets for improved website performance.
- [Favicon Generator](https://devdreaming.com/tools/favicon-generator) -- Convert a high-resolution PNG or JPG into all necessary ICO and various size PNG favicon files.
- [Placeholder Image Generator](https://devdreaming.com/tools/placeholder-image-generator) -- Generate placeholder images in SVG, PNG, or JPEG for mockups and prototypes.
- [Emoji Picker](https://devdreaming.com/tools/emoji-picker) -- Browse and copy emojis with Unicode references and search functionality.

## Security & Hashing

_Hash generators, token decoders (JWT), and security utilities for secure development workflows._

- [Hash Generator](https://devdreaming.com/tools/hash-generator) -- Generate MD5, SHA-1, SHA-256, and other hash values for text or files. Compare hashes for verification.
- [JWT Decoder](https://devdreaming.com/tools/jwt-decoder) -- Decode and inspect JSON Web Tokens (JWT) without sending them to an external server. View header, payload, and expiry.
- [Email Obfuscator](https://devdreaming.com/tools/email-obfuscator) -- Encode email addresses to prevent scraping by bots while still being readable by humans.
- [Checksum Calculator](https://devdreaming.com/tools/checksum-calculator) -- Calculate checksums using CRC-32, Adler-32, Fletcher-16, and simple checksum algorithms.

## Frontend & CSS

_CSS layout builders, converters, and visualizers for Flexbox, Grid, and modern UI effects._

- [Clamp() Calculator](https://devdreaming.com/tools/clamp-font-size-calculator) -- Generate the CSS `clamp()` function for fluid, responsive typography based on min, max, and viewport values.
- [Pixel to REM Converter](https://devdreaming.com/tools/px-to-rem-converter) -- Convert pixel values to REM/EM units based on a specified root font size (e.g., 16px).
- [Aspect Ratio Calculator](https://devdreaming.com/tools/aspect-ratio-calculator) -- Calculate dimensions based on a target aspect ratio (e.g., 16:9, 4:3) for images and videos.
- [Cursor CSS Previewer](https://devdreaming.com/tools/cursor-property-viewer) -- Preview all available CSS `cursor` property values (e.g., grab, pointer, progress).
- [CSS Triangle Generator](https://devdreaming.com/tools/triangle-generator) -- Generate pure CSS code for creating triangular shapes, common in tooltips and flags.
- [Box Model Visualizer](https://devdreaming.com/tools/css-box-model-visualizer) -- An interactive tool to understand padding, border, and margin on the CSS Box Model.
- [CSS Variables Generator](https://devdreaming.com/tools/css-variables-generator) -- Generate a set of semantic CSS Custom Properties (`--vars`) from a color palette.
- [Viewport Size Checker](https://devdreaming.com/tools/viewport-size-checker) -- Determine the exact viewport width and height of the current browser window.

## DevOps & Cloud

_Tools for working with Cron, Docker, Nginx, and system permissions (Chmod)._

- [Cron Expression Editor](https://devdreaming.com/tools/cron-expression-generator) -- A visual UI to build and validate Cron job schedules (e.g., `* * * * *`).
- [Chmod Calculator](https://devdreaming.com/tools/chmod-permission-calculator) -- Visually calculate UNIX file permissions (e.g., 755, 644) from checkboxes and output the numeric/symbolic code.
- [HTAccess Redirect Generator](https://devdreaming.com/tools/htaccess-redirect-generator) -- Create correct 301 and 302 redirect rules for Apache's `.htaccess` file.
- [Gitignore Generator](https://devdreaming.com/tools/gitignore-generator) -- Generate optimized `.gitignore` files for various languages and frameworks (Node, Python, Next.js).
- [CIDR Calculator](https://devdreaming.com/tools/cidr-range-calculator) -- Calculate IP address ranges and subnets from a CIDR block.
- [User Agent Parser](https://devdreaming.com/tools/user-agent-parser) -- Extract browser, OS, and device information from a raw User-Agent string.
- [HTTP Status Reference](https://devdreaming.com/tools/http-status-reference) -- Quick reference guide for HTTP status codes with descriptions and categories.
- [MIME Type Finder](https://devdreaming.com/tools/mime-type-finder) -- Look up MIME types for common file extensions with searchable reference.
- [Port Number Reference](https://devdreaming.com/tools/port-number-reference) -- Reference guide for common network ports with service names and protocols.
- [File Size Calculator](https://devdreaming.com/tools/file-size-calculator) -- Convert file sizes between bytes, KB, MB, GB, and TB.
- [ENV File Generator](https://devdreaming.com/tools/env-file-generator) -- Create .env files with environment variables and comments.
- [HTTP Header Parser](https://devdreaming.com/tools/http-header-parser) -- Parse and analyze HTTP request/response headers with category labels.

## SEO & Social Media

_Tools for optimizing meta tags, Open Graph cards, sitemaps, and campaign links._

- [Open Graph Preview](https://devdreaming.com/tools/open-graph-previewer) -- Preview how your page will look when shared on Twitter (X), Facebook, and LinkedIn (Open Graph/Twitter Card simulator).
- [Meta Tag Generator](https://devdreaming.com/tools/meta-tag-generator) -- Generate standard SEO meta tags (title, description, viewport) and preview search results.
- [XML Sitemap Generator](https://devdreaming.com/tools/xml-sitemap-generator) -- Generate a simple XML sitemap for smaller websites to submit to search engines.
- [Robots.txt Generator](https://devdreaming.com/tools/robots-txt-generator) -- Create a standard `robots.txt` file with proper Allow and Disallow rules for web crawlers.
- [UTM Builder](https://devdreaming.com/tools/google-analytics-utm-builder) -- Easily generate tracking links with UTM parameters for marketing campaigns (Source, Medium, Campaign).
- [Twitter Thread Preview](https://devdreaming.com/tools/twitter-thread-preview) -- Write and preview a sequence of tweets (a thread) to check character counts and formatting.
- [Schema Markup Generator](https://devdreaming.com/tools/json-ld-schema-generator) -- Generate JSON-LD Schema Markup (e.g., for Articles, Products) for enhanced search results.
- [Canonical Tag Generator](https://devdreaming.com/tools/canonical-tag-generator) -- Generate the correct `<link rel='canonical'>` tag for SEO to avoid duplicate content issues.

## JavaScript & Code

_Code converters, language-specific tools, and runtime utility generators._

- [Curl to Fetch Converter](https://devdreaming.com/tools/curl-to-fetch-converter) -- Convert a cURL command into a standard JavaScript `fetch` or `axios` request snippet.
- [Unix Timestamp Converter](https://devdreaming.com/tools/unix-timestamp-converter) -- Convert Unix epoch timestamps to human-readable dates and vice-versa (supports milliseconds).
- [Code Block Comparator](https://devdreaming.com/tools/code-block-comparator) -- Compare two code blocks side-by-side using a syntax-aware diff viewer.
- [Binary/Decimal Converter](https://devdreaming.com/tools/binary-decimal-converter) -- Convert between Binary, Decimal, Octal, and Hexadecimal number systems.
- [JSON Path Finder](https://devdreaming.com/tools/json-path-finder) -- Click on a JSON property to automatically generate the correct JSONPath or lodash-style path (e.g., `data.items[0].id`).
- [License Header Generator](https://devdreaming.com/tools/license-header-generator) -- Generate copyright and license headers for source code files.
- [TODO Comment Extractor](https://devdreaming.com/tools/todo-comment-extractor) -- Extract TODO, FIXME, and other task comments from your code.
- [Package.json Validator](https://devdreaming.com/tools/package-json-validator) -- Validate and analyze package.json files with best practice recommendations.

## Database & Backend

_Utilities for SQL, MongoDB, connection strings, and database schema manipulation._

- [SQL to JSON Converter](https://devdreaming.com/tools/sql-to-json-converter) -- Convert raw SQL query results (table format) into a structured JSON array of objects.
- [CSV to SQL Insert](https://devdreaming.com/tools/csv-to-sql-insert) -- Generate bulk `INSERT INTO` statements from a CSV file for database seeding.
- [MongoDB ObjectId Generator](https://devdreaming.com/tools/mongodb-objectid-generator) -- Generate valid 12-byte MongoDB ObjectIDs and parse their internal timestamp.
- [CSV Column Analyzer](https://devdreaming.com/tools/csv-column-analyzer) -- Analyze CSV data to detect column types, unique values, and statistics.

## Framework Specific

_Specialized tools and helpers for frameworks like Next.js, Vercel, and Shadcn._

- [Shadcn Theme Generator](https://devdreaming.com/tools/shadcn-theme-generator) -- Visually adjust colors and parameters to generate the custom CSS variables for a shadcn/ui theme.
- [Next.js Config Validator](https://devdreaming.com/tools/nextjs-config-validator) -- Validate Next.js configuration files, check for deprecated options, and generate valid configs.
- [React Hooks Generator](https://devdreaming.com/tools/react-hooks-generator) -- Generate boilerplate React hooks patterns with TypeScript support, including useState, useEffect, useCallback, and custom hooks.

---

_This is the Markdown twin of a page on **DevDreaming** -- free developer tutorials, tools, and AI resources. Source of truth: the canonical HTML URL above._