Developer tools
Formatters, minifiers, regex, SQL, UUIDs, mock data and other coding helpers — all client-side.
CSS Autoprefixer
Free online CSS autoprefixer — paste CSS and add the -webkit-, -moz-, -ms-, -o- vendor prefixes browsers still need. Runs entirely in your browser.
CSS Gradient Generator
Generate CSS linear, radial and conic gradients — pick type, angle and color stops, then copy a ready-to-paste background-image. Free, in-browser.
Data URI Encoder
Turn text into a self-contained data: URI with a chosen MIME type and Base64 or percent encoding. No sign-up, runs offline in your browser.
Fake Data Generator
Generate fake test data — names, emails, addresses, UUIDs and more — as CSV, JSON, SQL or XML. Up to 1000 rows, seedable. Free, in your browser.
File Tree Generator
Turn a list of file paths or an indented outline into an ASCII tree for READMEs and docs. Unicode or ASCII connectors, optional sorting. Free, in-browser.
Flask Session Cookie Decoder
Decode a Flask session cookie (itsdangerous) into readable JSON without the secret key — base64url, zlib payloads, signature timestamp. Free, in your browser.
UUID Generator
Generate UUIDs / GUIDs online: v4 (random), v7 (time-ordered), v1, and v5/v3 (namespace), one or in bulk. Runs entirely in your browser — nothing uploaded, free.
Gzip & Brotli Size Estimator
See the gzip and brotli compressed size of any code or text — raw bytes, bytes saved, percent reduction and ratio. Free, private, runs in your browser.
HTML Form Generator
Generate clean, accessible HTML form markup from a plain field list — labels, validation, selects, radios and textareas. Free, private, in-browser.
HTML Formatter
Pretty-print and beautify HTML with consistent indentation, in your browser. Handles void elements, comments, and preserves pre/script/style. Nothing is uploaded.
HTML Minifier
Minify HTML by collapsing whitespace and removing comments, in your browser. Preserves pre/script/style and significant inline spacing. Nothing is uploaded.
HTML Preview Bundler
Combine separate HTML, CSS, and JS into one self-contained, runnable HTML file you can open or share — in your browser. Nothing is uploaded.
Extract Tables from HTML
Paste HTML and pull out any <table> as clean CSV or JSON. Pick the table and output format. Runs in your browser, nothing is uploaded, free.
HTML to Markdown
Convert HTML into clean Markdown instantly in your browser — preserves headings, links, lists, code blocks, tables, and emphasis. Free, private, no upload, no sign-up.
HTML to Text
Strip HTML markup to clean, readable plain text in your browser — keeps paragraph and list structure, removes all tags. Free, private, no upload, no sign-up.
JavaScript Beautifier
Re-indent minified or obfuscated JavaScript into clean, readable source — strings, regex and comments preserved. Free, in your browser; nothing uploaded.
JavaScript Minifier
Minify JavaScript online: strip whitespace, line breaks and comments without changing behavior — strings and regex kept verbatim. Free, in-browser, no upload.
JSON-LD Schema Markup Generator
Generate schema.org JSON-LD structured data for Article, Product, FAQ, Organization, Event, Recipe and more — a ready-to-paste script tag, free in your browser.
JSON to TypeScript
Paste JSON and get TypeScript interfaces — nested types, optional fields, and unions inferred automatically. Runs in your browser, nothing is uploaded, free.
Mock Data Generator
Generate realistic mock JSON from a shorthand schema — your own fields, 30+ types, nested objects, arrays, and a seed to reproduce. Free, in-browser.
Page Weight Analyzer
Analyze page weight from pasted HTML — resource counts, render-blocking scripts and styles, inline JS/CSS sizes, and a page-weight budget. Free, in-browser.
PEM → JWK converter
Convert a PEM-encoded RSA or EC key into a JSON Web Key (JWK), in your browser. Nothing is uploaded.
JSON → PHP serialize()
Convert JSON to PHP serialize() format in your browser — byte-accurate strings that PHP's unserialize() can read. Free, private, no sign-up.
PHP unserialize() → JSON
Decode a PHP serialize() string to readable JSON in your browser. Inspect PHP sessions and WordPress wp_options values. Free, private, no sign-up.
Regex Extract
Run a regular expression over text and extract every match — case-insensitive, multiline, dot-all, capture groups, dedupe. Free, in your browser.
Regex Tester
Test regular expressions online — see every match with positions plus the value and span of each numbered and named capture group. Free, in-browser, no upload.
Jinja2 Template Renderer
Render a Jinja2 template against JSON or YAML data in your browser — variables, loops, conditionals and filters. Free, private, no upload.
Template Renderer
Render a Handlebars or Mustache template against JSON data in your browser — {{variables}}, nested paths, {{#each}} loops and {{#if}} conditionals. Free, private.
SEO Audit
Paste a page's HTML and get a scored on-page SEO audit — title, meta description, headings, image alt text, canonical, and Open Graph tags. Free, private, no upload.
Sitemap URL Extractor
Paste an XML sitemap or sitemap index and pull out every URL (and lastmod date) as a clean list — in your browser. Nothing is uploaded.
SQL Formatter
Format, beautify and standardize SQL queries in your browser. Clauses on their own lines, configurable indentation, keyword casing. Nothing is uploaded.
SQL Playground
Run SQL in your browser against a fresh in-memory database — CREATE TABLE, INSERT, SELECT, JOIN — with table, CSV, or JSON output. Free and private.
Structured Data Validator
Validate schema.org structured data from pasted HTML — extract JSON-LD, microdata and RDFa and flag markup errors, locally in your browser.
Syntax Highlighter
Syntax-highlight a code snippet to self-contained inline-styled HTML (or ANSI terminal colors) for 100+ languages and many themes, in your browser. Nothing is uploaded.
Text Diff
Compare two text blocks and highlight added, removed, and changed lines.