Developer Toolbox
100 tools. No signups, no uploads — every tool runs locally in your browser.
Find the free online developer tools people search for most: SQL query generators, JSON formatters, TypeScript type generators, UUID tools, Base64 encoders and decoders, cron job builders, color converters, and more. Everything runs locally, with no signup and no uploads.
Favorites: 0/9
Encoding & Crypto
9Encode text or files to Base64 and decode Base64 strings back to text.
Generate, validate, and inspect UUIDs (v1, v4, v5).
Generate SHA and CRC32 checksums for text and files instantly.
Decode JWT header and payload, check expiry, and verify HS256/RS256/ES256 signatures.
Break a URL into its components, decode query parameters, and strip tracking params.
Percent-encode URLs or individual components and decode them back.
Generate cryptographically strong random secrets for JWT signing.
Generate a base64-encoded APP_KEY for Laravel applications.
Generate .htpasswd entries and bcrypt password hashes for Apache and Nginx basic auth.
Data & Text
22Repair malformed JSON, parse JSON5/JSONC, query, validate schemas, and generate model code.
Minify HTML, CSS, and JavaScript to shrink file size, or beautify minified code back into readable formatting.
Test and debug regular expressions with live match highlighting, capture groups, and search-and-replace.
Compare two blocks of text and highlight added, removed, and changed lines.
Write Markdown and see a live rendered preview side-by-side.
Convert Markdown to clean, ready-to-use HTML instantly with a live preview.
Count words, characters, sentences, and paragraphs with reading time, keyword density, and SEO length limits.
Beautify or minify XML and check well-formedness with line and column error reporting.
Build a Markdown table visually, or import CSV/TSV data, with per-column alignment, sorting, and transpose.
Extract text from screenshots, scans, and photos in your browser, with Markdown table extraction and hOCR/TSV export.
Compare two screenshots pixel by pixel, or by the text inside them with OCR, and highlight what changed.
Black out, blur, or pixelate text, faces, and secrets in a screenshot, then export a flattened PNG with the metadata stripped.
Write and preview Reddit posts with live markdown rendering, spoiler support, and a quick-insert toolbar.
Transform text to camelCase, snake_case, PascalCase, kebab-case, and more.
Turn any string into a URL-safe slug with custom separators.
Generate placeholder text by paragraphs, sentences, or word count for mockups and development.
Generate TypeScript interfaces and type aliases from JSON input.
Generate Java classes with fields, getters/setters, and Jackson annotations from JSON.
Convert XSD schemas and DTDs into Java classes with JAXB annotations and Lombok support.
Convert .env files to JSON and back. Parse quoted values and inline comments in your browser.
Redact or mask PII, credentials, and API keys (AWS, GitHub, Stripe, JWT) from logs, code, and prompts.
Convert between JSON, TOML, and XML formats with syntax highlighting.
Converters
17Convert Unix timestamps to human dates and vice versa, any timezone.
Convert JSON to YAML format locally in your browser.
Convert YAML manifests and config files to JSON instantly.
Convert JSON documents to XML format instantly in your browser.
Convert XML payloads and config files to JSON in real time.
Convert JSON documents to TOML format instantly in your browser.
Convert TOML files to clean, formatted JSON with no uploads.
Convert CSV to JSON or JSON arrays to CSV, with nested fields and custom delimiters.
Convert Clojure EDN files to clean, formatted JSON.
Convert JSON back into Clojure EDN with keywords, sets, and tags.
Instantly convert integers between decimal, hex, binary, and octal.
Compare and convert times across multiple global time zones with a visual timeline.
Parse semantic version strings and explain each part (major.minor.patch).
Convert text to dot-dash Morse code and decode Morse back to text.
Convert integers to Roman numerals and validate Roman numeral strings.
Convert math expressions to LaTeX code, or paste LaTeX and preview it rendered.
Convert length, mass, temperature, speed, energy, and more across metric and imperial units.
Generators
6Create strong random passwords, passphrases, or memorable mnemonic passwords.
Generate QR codes from text or URLs with customizable size and colors.
Build and visualise cron expressions with a human-readable schedule.
Build Conventional Commit messages with type, scope, and breaking flags.
Create Code 128, EAN-13, UPC-A, and more — download as SVG or PNG.
Generate a combined .gitignore file for any language, framework, or tool.
SQL & Data
5Generate realistic fake data as JSON, SQL INSERT, CSV, or MongoDB.
Build SELECT queries visually with joins, filters, and aggregations.
Format and beautify SQL queries with support for PostgreSQL, MySQL, BigQuery, SQLite, and more.
Generate Drizzle ORM table schemas for PostgreSQL, MySQL, and SQLite with custom fields and constraints.
Convert CREATE TABLE statements into JPA entity classes for MySQL, PostgreSQL, SQLite, SQL Server, and Oracle.
Design & Frontend
11Convert colors between HEX, RGB, HSL, and other formats.
Check WCAG contrast ratios between foreground and background colors.
Generate random colors with lock, palette history, and copy support.
Build a cohesive UI color palette from a single seed color.
Visually configure flex-direction, wrap, alignment, and spacing to generate clean CSS.
Visually configure grid rows, columns, gaps, and item placement, then generate clean CSS.
Calculate fluid clamp() values for responsive font sizes and spacing between two viewport widths.
Preview Open Graph and Twitter card meta tags as they appear when shared.
Quick reference for image dimensions across social media, web, screens, and print formats.
Turn any image into a complete favicon set for browsers, iOS, and Android.
Visually compose Tailwind utility class strings with live preview and ready-made component templates.
Media Tools
8Convert HEIC images to JPG format with adjustable compression quality.
Convert JPEG images to PNG format while preserving quality and transparency.
Convert JPEG images to modern WebP format for better compression and faster loading.
Convert WebP images back to PNG format for broader compatibility.
Convert PNG images to WebP format for optimized file sizes and modern web delivery.
Convert AVIF images to JPG for compatibility with systems that don't support the newer format.
Convert multiple images between formats (JPG, PNG, WebP, AVIF) in one go.
Convert images between any supported formats with advanced options for quality, compression, and resizing.
DevOps & Config
10Paste nginx access logs and get them parsed into readable, searchable rows.
Build an .eslintrc config with extends, plugins, and rule presets.
Visually configure next.config.js with common feature toggles.
Generate a webpack.config.js with loaders, plugins, and mode options.
Compose Ansible playbook YAML with tasks, handlers, and variables.
Generate HCL snippets for AWS, GCP, and Azure resources.
Generate Fail2ban jail configs with filters and action templates.
Build docker run and docker build commands visually — ports, volumes, env vars, and flags.
Build curl commands visually — headers, query params, body, and auth, live-previewed and copy-ready.
Paste a curl command and convert it into Python, JavaScript, Node.js, or Go request code.
System & Browser
2PDF Utilities
10Combine multiple PDF files into a single document, in any order you choose.
Extract specific pages from a PDF or split it into one file per page.
Shrink a PDF's file size by choosing a compression level, right in your browser.
Convert every page of a PDF into a PNG or JPEG image, individually or as a ZIP.
Combine JPEG, PNG, or WebP images into a single PDF, one image per page.
Rotate every page of a PDF — or just the ones you pick — 90° at a time.
Stamp page numbers onto every page of a PDF, in the position and format you choose.
Stamp a custom text watermark like CONFIDENTIAL or DRAFT across every page of a PDF.
Drag PDF pages into a new order and export the reorganized document.
Select the pages you don't need and export a trimmed PDF.
Your Data Never Leaves Your Device
Every tool runs entirely in your browser. Nothing you type is uploaded, stored, or logged on our servers.