All tools

Format, minify and validate JSON, pinpointing syntax errors to an exact line and column. Optional key sorting; runs in your browser.

Turn JSON into TypeScript interfaces, Go structs, Java classes or Rust structs, with missing keys marked optional. Runs locally in your browser.

Format SQL online: one clause per line, consistent keyword case, subqueries indented deeper. Minify strips comments and extra whitespace, all locally.

Format XML online by tag level, with comments, CDATA and DOCTYPE on their own lines and attribute values left untouched. Runs locally in your browser.

Format HTML online by tag level, keeping text and inline tags on one line and script or pre content untouched. Runs locally, with nothing uploaded.

Format CSS online: one declaration per line, selectors split at commas. Minify only strips structural whitespace, keeping meaningful spaces in values.

Beautify minified JavaScript by re-indenting on braces and semicolons, with strings and comments kept verbatim. Indentation only, nothing uploaded.

Convert text to Base64 and back, with correct UTF-8 handling for accents, CJK and emoji. Runs entirely in your browser — nothing is uploaded.

Escape text into %XX form and back again, treating a whole URL and a single parameter value as different jobs. Runs entirely in your browser.

Turn < > & and quotes into HTML entities and decode them back in a single pass, so &amp;lt; becomes &lt;, not an angle bracket. Runs in your browser.

Split a JWT into header, payload and signature, and read iat, nbf and exp as dates. The signature is not verified — decoding only, all in your browser.

Convert non-ASCII text and emoji into \uXXXX or \xXX escapes and back, with emoji written as proper surrogate pairs. Runs entirely in your browser.

Compute MD5, SHA-1, SHA-256 or SHA-512 digests of any text, hashed as UTF-8 bytes so they match openssl and sha256sum exactly. Runs in your browser.

Sign a message with a secret key using HMAC and get a result matching Node, Java and Python. The key never leaves your browser — nothing is uploaded.

Convert Unix timestamps into readable dates and back, with seconds and milliseconds told apart, a time zone picker and batch mode. Runs in your browser.

Count the days, weeks or months between two dates, or shift a date by any of those. Dates can be picked from a calendar or pasted in — nothing is uploaded.

Convert numbers between binary, octal, decimal, hex and base 36, with long IDs converted digit for digit. Runs entirely in your browser.

Explain a cron expression field by field and list its next run times, saying plainly when a schedule can never fire. Runs entirely in your browser.

Convert a colour between HEX, RGB, HSL and HSV, and check whether text and background clear the WCAG AA or AAA contrast ratio, all locally.

Convert between units of length, weight, temperature, volume and more, seeing one value in every unit of its category at once, all in your browser.

Compare two blocks of text online and highlight added, removed and unchanged lines, so only the lines that changed are marked. Runs in your browser.

Count Chinese characters and English words separately, alongside characters, lines, real UTF-8 bytes and reading time. Runs in your browser.

Clean up a column pasted out of a log or spreadsheet: deduplicate, sort, drop blank lines, trim whitespace and strip line numbers, all in your browser.

Convert identifiers between eight naming styles. Words are split correctly first, so acronyms such as HTTPServer come out right, all in your browser.

Convert Chinese between simplified and traditional characters, leaning on common words first and the most usual form for the rest, all in your browser.

Test a regular expression with live highlighting, capture groups and a replace preview, guarded against catastrophic backtracking. Runs in your browser.

Write Markdown on the left and see it rendered on the right, with pasted HTML shown as text and images never fetched. Runs entirely in your browser.

Generate a whole column of UUID v4, v7, ULID or NanoID values, one per line, ready to paste into a spreadsheet. Runs entirely in your browser.

Generate placeholder text as Latin lorem ipsum, English sentences or Chinese filler, in paragraphs, sentences or words, all in your browser.

Describe your fields once and get a batch of realistic mock records, exportable as JSON, CSV or a SQL INSERT. Everything is generated in your browser.

Turn text or a link into a QR code as you type, downloadable as a PNG or a vector SVG. The encoding happens in your browser, never on a server.

Generate strong random passwords with a live entropy readout, so strength becomes a number you can compare. Passwords stay in memory, never uploaded.

Parse a URL into scheme, host, port, path, query parameters and fragment, with each parameter shown raw and decoded. Runs entirely in your browser.

Parse a user agent into browser, version, OS, device type and engine, and see which rules matched. Pattern matching only. Runs entirely in your browser.

Look up an HTTP status code for its meaning, 1xx–5xx class, typical uses and common traps. Runs entirely in your browser.

Look up a MIME type from an extension, or the default extension for a media type. Common types only. Runs entirely in your browser.

Generate a .gitignore from language, framework, editor and OS templates. Sections are merged and duplicates removed. Runs entirely in your browser.

Convert an image to Base64 or a data URL by dropping, choosing or pasting it. Resize and switch format, all locally — nothing is ever uploaded.