All tools

Beautify, minify and validate JSON, sort by key and see the exact error position. Everything runs in your browser — your data never leaves your device.

Convert text to and from Base64, with URL-safe output and full UTF-8 support for Chinese and emoji. Runs entirely in your browser.

Percent-encode and decode, with separate modes for a parameter value and a whole URL, plus a breakdown that decodes each query parameter.

Generate UUID v4 (random) and v7 (time-sortable) in bulk, with uppercase and hyphen-free options, using the browser's cryptographic randomness.

Convert between Unix timestamps, ISO 8601 and local time, detecting seconds or milliseconds automatically and showing the time zone and relative time.

Decode a JWT's header and payload, with expiry times rendered as readable dates. Decoding only — the token never leaves your browser and is never stored.

Compute SHA-1, SHA-256, SHA-384 and SHA-512 with Web Crypto, in hex or Base64, optionally all at once.

Test regular expressions live: every match position, captured groups and a replacement preview, with support for the g, i and m flags.

Paste a .env file and get a .env.example that is safe to commit: keys, passwords and connection strings are masked, comments and harmless settings are kept.

Convert names between camelCase, PascalCase, snake_case, CONSTANT_CASE and kebab-case — acronyms and digits handled correctly, many lines at once.

Convert between JSON arrays and CSV: nested objects flattened, quotes and line breaks handled, leading zeros kept, and CSV injection flagged.

Compare two texts line by line with +/- output, optionally ignoring whitespace and case, showing everything or just three lines of context.

Beautify or minify SQL for PostgreSQL, MySQL, SQLite, SQL Server, BigQuery and more, with consistent keyword case.

Check versions against npm ranges like ^ and ~, compare and sort versions, and calculate the next version — exactly as npm does.

Build a five-field cron expression from presets or fields, with a plain-language description of when it actually runs. Works with crontab and Vercel Cron.

Derive TypeScript interfaces or types from a JSON sample, including nested objects and arrays, with named sub-types instead of one giant inline shape.

Convert between YAML and JSON in both directions — anchors, block scalars and multi-document streams included — and say so when a conversion loses information.

Preview CSS gradients live while adjusting the angle, colour stops and type — linear, radial or conic — then copy the background rule in one click.

Measure foreground against background, judge WCAG AA and AAA by text size, and suggest a colour that passes when it does not.

Drag offset, blur and spread to preview a shadow instantly, and get a box-shadow rule you can paste straight into your stylesheet.

Convert PNG and JPG to WebP in your browser, in batches, with quality and width controls. The images are never uploaded to a server.

Shrink image file size in your browser: choose JPEG, WebP or PNG, adjust quality and maximum width. Nothing is uploaded to a server.

Generate title, description, canonical and robots tags, with live warnings when they exceed the length search results actually display.

Generate a robots.txt and test, with the same rules, whether a given path ends up allowed or blocked — plus one-click blocking for the common AI crawlers.

Paste your sitemap.xml to check the root element, namespace, loc URLs, lastmod dates, duplicates and the 50,000-entry limit.

Generate Content-Security-Policy, HSTS, X-Content-Type-Options and the rest, in plain, nginx or vercel.json form — with warnings for the settings that usually backfire.

Generate schema.org JSON-LD for Article, FAQPage, Organization, Product and breadcrumbs, with warnings for the properties Google requires.

Generate og:title, og:description, og:image and Twitter Card tags, with guidance on preview image size and the usual pitfalls.

Turn a list of languages and URLs into hreflang link tags, HTTP Link headers or sitemap entries, checking the language codes, absolute URLs and x-default.

Tick your languages, frameworks, OS and editor to get a lean, de-duplicated .gitignore that keeps .env files and private keys out by default.

Pick MIT, Apache-2.0, GPL or another open source licence, fill in the holder and year, and get the LICENSE file or the official file header — with its SPDX identifier.

Pick Node.js, Python, Go or Rust and get a ready-to-use GitHub Actions CI workflow: lint, test, build, a version matrix, caching and least-privilege permissions.

Generate GitHub bug report and feature request forms (Issue Forms), a pull request template and config.yml — in English or Chinese.

Enter a GitHub repo and get the Markdown for README badges — CI status, licence, stars, npm version and downloads — in one go.