Developer Tools

Convert numbers between binary, octal, decimal, and hexadecimal. Supports huge numbers via BigInt. Handles 0b, 0o, 0x prefixes.

Pick a preset or enter your own fields to build a cron expression. Includes a plain-English explainer so you know exactly when it will run.

Beautify minified CSS with proper indentation, or minify pretty CSS to a single line. Preserves comments. Runs in your browser.

Instantly compute MD5 and SHA-family hashes of any text. All hashing happens in your browser — nothing is uploaded, nothing logged.

Beautify minified HTML with proper indentation, or minify pretty HTML for production. Preserves script, style, and pre blocks. Runs in your browser.

Every common HTTP header explained, grouped by purpose. Searchable by name or keyword. Includes examples and RFC 9110 references.

Every HTTP status code you need to know, grouped by category, with plain-English descriptions. Searchable by code, name, or keyword.

Format, validate, and minify JSON in your browser. See parse errors with line/column. Optional key sorting. Nothing is uploaded.

Escape any text for safe embedding as a JSON string, or unescape a JSON string back to plain text. Handles quotes, backslashes, tabs, and unicode.

Paste a JSON blob and get TypeScript interface declarations. Handles nested objects, arrays, and union types. Runs in your browser.

Paste any JSON Web Token (JWT) to see the decoded header, payload, and expiration status. Everything happens in your browser — the token never leaves your device.

Generate strong random passwords with configurable length, character sets, and ambiguity-avoidance. Live entropy meter shows crack time.

Generate random numbers in any range. Integers or decimals, unique or with repeats, Math.random or Web Crypto for cryptographic randomness.

Test JavaScript regular expressions against any string with live match highlighting, capture groups (named and numbered), and optional replace.

Convert any number (1–3999) to Roman numerals and back. Validates canonical form and suggests corrections for non-canonical input.

Format and beautify SQL for 10 dialects including PostgreSQL, MySQL, SQLite, BigQuery, Snowflake, and T-SQL. Uppercase keywords, custom indent.

Generate cryptographically-strong UUIDs in bulk. Supports v4 (random), v7 (time-ordered), and the nil UUID. Formatting options included.

Format XML with proper indentation, validate against the XML spec, or minify to a single line. Uses the browser DOMParser for validation.

Format and validate YAML in your browser. Multi-document (---) supported. Errors point to line and column. YAML 1.2 spec.