All Your Developer Tools in One Place

Paste ugly JSON, get pretty JSON. That's it. It also validates and shows you where the errors are. The tree view lets you explore nested JSON structures. Click to expand objects and arrays. Search finds anything in your JSON. Auto-fix handles those annoying trailing commas and unquoted keys. Need TypeScript interfaces from your JSON? Python classes? Java POJOs? The export tab generates them. Everything runs in your browser. Your JSON never leaves your device.

Encode text, files, and images to Base64. Decode them back to files you can download. Generate data URIs for embedding images in HTML or CSS. Drag and drop files. See image previews instantly. Get data URIs with the correct MIME type. URL-safe encoding when you need it. Everything runs in your browser. Your files never touch a server. Works offline after it loads.

Encode and decode URLs using different methods (encodeURI, encodeURIComponent, form data). Parse URLs into protocol, domain, path, query, and fragment. Edit each part separately and rebuild the URL. Query Manager gives you a table to add, edit, and delete parameters without messing with ampersands and equals signs. Compare encoding methods side-by-side to see the difference. Handle Punycode domains. Detect double-encoded URLs. Works in your browser. Never sends URLs to a server.

Paste a JWT token. See the header, payload, and signature decoded instantly. Color-coded structure shows you exactly what's in each part. Live countdown shows time until expiration. Security warnings flag weak algorithms ('none' is bad). Claims validation shows what's missing. Compare two tokens side-by-side to spot differences. Everything happens in your browser. Your tokens never leave your device. Get code examples in JavaScript, Python, PHP, Go, C#.

Convert Unix timestamps to dates in any format: ISO 8601, RFC 2822, SQL, relative time ('2 days ago'), Excel serial, Julian day. Handle multiple timezones. See the same moment across UTC, EST, PST, JST. Add or subtract time. Calculate exact age. Compare timestamps. Batch convert hundreds at once. Get code snippets for JavaScript, Python, PHP, Go, SQL, Java. Detects Y2038 problem. Quick shortcuts for now, today, yesterday, week/month/year start. Everything runs in your browser.

Pick a color visually. See it in HEX, RGB, HSL, CMYK instantly. Convert between any format with one click. Generate color palettes: complementary, analogous, triadic, split-complementary. Create shades and tints for design systems. Check WCAG contrast ratios (AA, AAA compliance). Simulate color blindness (protanopia, deuteranopia, tritanopia). Create CSS gradients with visual editor. Export palettes as CSS variables, SCSS, Tailwind config, JSON. Everything runs in your browser.

Quick API testing in your browser. Send GET, POST, PUT, DELETE requests. See responses with status codes, headers, and formatted bodies. Generate ready-to-use code snippets. **CORS Limitation**: Browsers block cross-origin requests without proper CORS headers. If the API doesn't allow browser requests, you'll only see OPTIONS preflight. Use the generated cURL command in terminal instead — it bypasses CORS completely. Supports Bearer tokens, Basic Auth, API keys. Body types: JSON, form data, URL-encoded, raw text. History saved locally. Code generation for cURL, fetch, axios, Python, PHP. Good for: quick API tests, code generation, APIs with CORS enabled, localhost testing. Not good for: APIs without CORS (use terminal/Postman instead).

Generate UUIDs in all versions from v1 to v7. v4 for random IDs. v7 for database primary keys (sortable by time). v5 for deterministic UUIDs from names. Bulk generate up to 1000 at once. Multiple formats: standard, uppercase, no hyphens, URN, GUID, Base64. Inspector shows version, variant, timestamp, and field breakdown. Compare two UUIDs side-by-side. Get code snippets for your language. Everything runs in your browser.

Create JWT tokens with custom claims and sign them. All algorithms supported: HS256 (shared secret), RS256/ES256 (public/private key pairs). Add standard claims like subject, expiration, issuer. Add custom claims like roles or permissions. Templates for common use cases: API access, user session, OAuth. Expiration presets (15min, 1hr, 24hr, 7days). Get code snippets for JavaScript, Python, PHP, Go, Java, C#. Everything uses Web Crypto API in your browser. For testing only — never use browser-generated keys in production.

Hash text with MD5, SHA-1/256/384/512, SHA-3, and RIPEMD-160. Generate HMAC signatures for APIs. Hash files to verify integrity. Educational password hashing with PBKDF2. Multiple output formats: hex, Base64, Base64-URL. Security indicators show which algorithms are broken (MD5), deprecated (SHA-1), or secure (SHA-256, SHA-3). File hashing includes progress tracking. Everything happens in your browser. Your files and data never leave your device.

Paste two versions of text or code. See what changed. Split view shows them side-by-side. Unified view shows changes inline like git diff. Ignore whitespace to focus on actual changes. Word-level highlighting shows exactly which characters changed. Navigate with keyboard shortcuts (n for next, p for previous). Click line numbers to get a permalink. Everything runs in your browser.

Type or paste text. See word count, character count, sentence count, paragraph count instantly. Calculate reading time. Check readability scores (Flesch-Kincaid, Gunning Fog). Word frequency shows which words you use most. Writing goal tracking. Text transformations (uppercase, lowercase, sentence case). All updates in real-time as you type. Perfect for essays, articles, blog posts, content writing. Everything runs in your browser.

Write markdown on the left. See the rendered preview on the right. Updates as you type. GitHub Flavored Markdown (GFM) with tables, task lists, strikethrough, auto-linking. Code blocks with syntax highlighting. Mermaid diagrams (flowcharts, sequence diagrams). Math rendering with LaTeX. Export to HTML, PDF, or markdown file. Toolbar for quick formatting. Templates for README, blog posts, docs. Auto-save to localStorage. Works offline. Everything runs in your browser.

Type a regex pattern. See all matches highlighted in real-time. Capture groups shown with different colors. Match count, positions, and statistics displayed instantly. Pattern library has common regexes: email, URL, phone, dates, IPs. Find & replace with backreferences and named groups. Pattern explainer breaks down what each part does in plain English. Code generation for JavaScript, Python, Java, PHP, Ruby, Go, C#, Rust, SQL, Perl. Warns about catastrophic backtracking. Everything runs in your browser.