Free Developer Tools That Run in Your Browser

55 free tools — JSON, Base64, hashes, regex, UUIDs, and encoders

JSON Formatter

Format and beautify JSON data with proper indentation and syntax highlighting. Validates JSON structure while formatting.

JSON Validator

Validate JSON syntax and structure. Detects errors, shows line numbers, and provides helpful error messages.

JSON Minifier

Minify JSON by removing whitespace and unnecessary characters. Reduces file size for production and APIs.

Markdown to HTML

Convert Markdown to HTML. Transform markdown documents into styled HTML for web pages.

URL Encoder

Encode text for use in URLs. Convert special characters to percent-encoded format.

URL Decoder

Decode percent-encoded URLs. Convert encoded URLs back to readable text.

Base64 Encoder

Encode text or binary data to Base64. Convert strings and files for safe transmission.

Base64 Decoder

Decode Base64 to text or binary. Convert Base64 strings back to original data.

HTML Entity Encoder

Encode text to HTML entities. Convert special characters for safe HTML display.

HTML Entity Decoder

Decode HTML entities to text. Convert & < > back to original characters.

JWT Decoder

Decode and inspect JWT tokens. View header, payload, and signature without verification.

Unix Timestamp Converter

Convert between Unix timestamps and human-readable dates. Support seconds and milliseconds.

Regex Tester

Test regular expressions against sample text. See matches, groups, and debug patterns in real-time.

UUID Generator

Generate UUIDs (Universally Unique Identifiers). Create v4 random UUIDs for IDs and keys.

Hash Generator (MD5/SHA)

Generate MD5, SHA-1, SHA-256, and other hashes. Hash text and files for checksums and integrity.

JSON to CSV

Convert JSON data to CSV format. Flatten nested objects and arrays into spreadsheet-ready columns.

CSV to JSON

Convert CSV files to JSON format. Parse spreadsheet data into structured JSON objects or arrays.

JSON to YAML

Convert JSON to YAML format. Transform structured data for config files, Kubernetes, and DevOps workflows.

YAML to JSON

Convert YAML to JSON format. Parse YAML config files into JSON for APIs and JavaScript applications.

JSON to XML

Convert JSON data to XML format. Transform structured data for legacy systems and XML-based APIs.

XML to JSON

Convert XML to JSON format. Parse XML documents into JSON for modern applications and APIs.

XML Formatter

Format and beautify XML with proper indentation. Make XML documents readable and validate structure.

HTML Formatter

Format and beautify HTML code with proper indentation. Make messy HTML readable and maintainable.

CSS Formatter

Format and beautify CSS with proper indentation. Make stylesheets readable and easier to maintain.

CSS Minifier

Minify CSS to reduce file size. Remove whitespace and comments for faster page loads.

JavaScript Formatter

Format and beautify JavaScript code. Add proper indentation and line breaks for readability.

JavaScript Minifier

Minify JavaScript to reduce file size. Remove whitespace and comments quickly in the browser.

SQL Formatter

Format SQL queries with proper indentation. Make complex queries readable and easier to maintain.

PHP Formatter

Format PHP code with proper indentation. Beautify PHP for readability.

Python Formatter

Format Python code. Normalise indentation, blank lines, and spacing around colons.

TOML to JSON

Convert TOML config files to JSON. Parse Rust, Python, and other config formats into JSON.

JSON to TypeScript

Generate TypeScript interfaces from JSON data. Create type definitions for your API responses.

HTML to Markdown

Convert HTML to Markdown format. Transform web content into markdown for documentation and blogs.

Markdown Preview

Preview Markdown in real-time. See how your markdown renders as HTML as you type.

HTML to JSX

Convert HTML to JSX for React. Transform HTML snippets into valid React/JSX syntax.

Base64 Image Encoder

Convert images to Base64 data URIs. Embed images in HTML, CSS, or JSON.

Cron Expression Generator

Generate cron expressions for scheduling. Create schedules for scripts, jobs, and automation.

Number Base Converter

Convert numbers between binary, decimal, hexadecimal, and octal. Support any base from 2 to 36.

Epoch Converter

Convert epoch time to human-readable dates. Shows seconds, milliseconds, microseconds and nanoseconds.

ULID Generator

Generate ULIDs (Universally Unique Lexicographically Sortable Identifiers). Time-sortable unique IDs.

Random String Generator

Generate random strings. Create alphanumeric strings, custom length, for tokens and IDs.

.htaccess Generator

Generate .htaccess rules for Apache. Redirects, force HTTPS, IP deny, password protect and custom error pages.

robots.txt Generator

Generate robots.txt files. Control crawler access, sitemaps, and crawl delays.

Meta Tag Generator

Generate meta tags for SEO. Create title, description, viewport, and other essential meta tags.

Open Graph Generator

Generate Open Graph meta tags. Control how links appear when shared on Facebook, LinkedIn, and more.

Schema Markup Generator

Generate JSON-LD schema markup. Create structured data for rich snippets and SEO.

Favicon Generator

Generate favicons from images. Resize an upload to standard PNG favicon sizes and copy the HTML link tags.

SVG to CSS

Convert SVG to CSS background. Embed SVG as a URL-encoded data URI for background-image.

Box Shadow Generator

Create CSS box-shadow values visually. Multiple shadows, blur, spread, and color.

Border Radius Generator

Create border-radius values. Generate rounded corners, pill shapes, and custom radius values.

Flexbox Playground

Experiment with CSS Flexbox. Visual playground to learn justify-content, align-items, and flex properties.

Grid Generator

Generate CSS Grid layouts visually. Create grid templates and responsive grids.

Sitemap Generator

Generate XML sitemaps for SEO. Create sitemap.xml from a list of URLs.

JSON Schema Generator

Generate JSON Schema (draft-07) from JSON data. Create validation schemas for APIs and data validation.

Placeholder Image Generator

Generate placeholder images. Create dummy SVG images by size, color, and text for development.

About Developer Tools

Developer tools cover the small daily tasks of writing and debugging code: formatting and validating JSON, encoding and decoding Base64 or URL strings, generating UUIDs, hashing text with MD5 / SHA-1 / SHA-256 / SHA-512, decoding JWTs, testing regular expressions, converting Unix timestamps, and escaping HTML entities. All 15 tools run in your browser, so tokens, payloads, and request bodies you paste stay on your machine.

Working with an API and need to see what a token contains? Paste it into the JWT decoder. Cleaning up a payload from a webhook? Format it with the JSON formatter and validate the shape. Writing a regex and want to see live matches? The regex tester highlights every capture group as you type. Need a fingerprint of a string? The hash generator produces all four common digests side by side.

Every result updates in real time and is one click from your clipboard. Nothing is sent to any server — useful when you're inspecting production data, auth tokens, or anything else that shouldn't leave your laptop.