Tools

Format, minify, and validate JSON text in your browser.

Convert Unix seconds or milliseconds into local, ISO, and UTC time.

Edit HTML, CSS, and JavaScript with a network-enabled sandbox preview.

A Markdown notebook with local persistence, import/export, and optional AI summaries.

Convert UTF-8 text to Base64 and back instantly, with standard and URL-safe formats and full support for Unicode and emoji.

Encode URL parameters or full URIs and decode percent escapes, with explicit handling of spaces, plus signs and Unicode.

Escape HTML special characters or decode named and numeric entities. Optionally encode non-ASCII characters as numeric entities.

Convert readable text to Unicode escapes and back, including UTF-16 pairs, code point escapes, emoji and common control characters.

Inspect a JWT header and payload separately, and read issued-at, not-before and expiry claims as UTC dates.

Calculate SHA-256, SHA-384, SHA-512, SHA-1 and MD5 hashes of UTF-8 text, with a copy button for each result.

Calculate a file checksum locally and compare it with an expected value to check a download or a transferred file.

Calculate HMAC-SHA-256, SHA-384 or SHA-512 using a text or hexadecimal key, useful for checking API signature inputs.

Generate RFC 9562 UUID v4 or v7 values in batches, with uppercase output, individual copying and text download.

Generate secure random passwords with your choice of length and character groups, optionally excluding look-alike characters.

Count characters, words, lines, paragraphs and UTF-8 bytes as you type, with support for combined characters and emoji.

Change letter case or convert names to camelCase, PascalCase, snake_case and other common identifier styles, including Unicode text.

Remove duplicate or blank lines, trim whitespace, sort naturally and add a prefix or suffix to every line, with instant preview.

Compare two texts line by line, see added and removed content with line numbers, and download the differences.

Test JavaScript regular expressions, inspect match positions and capture groups, and preview text replacements as you type.

Convert CSV or TSV to JSON and back, with quoted fields, embedded newlines, Unicode and a table preview.

Validate and format XML locally with two- or four-space indentation, preserving mixed text and xml:space whitespace.

Convert integers exactly between bases 2–36, including negative and very large values, with common base results shown together.

Convert length, mass, area, volume, temperature, speed, data size and time, with editable values on both sides.

Find a percentage of a number, calculate what share a part represents, or measure the percentage change between two values.