Developer tools

Translate a cron expression into plain English, field by field.

Build a cron expression from common schedules and confirm what it will do.

Escape a string so it is valid as a CSS identifier in a selector.

Format CSS with one declaration per line, or minify it for production.

Turn a curl command into JavaScript fetch, Axios or Python requests code.

Find files that are byte-for-byte identical by comparing their SHA-256 hashes.

Pull every email address out of a block of text, deduplicated if you want.

Read raw email headers: delivery path, timings, and SPF, DKIM and DMARC results.

Tidy a list of email addresses: deduplicate, normalise case and find malformed entries.

Turn a .env file into a .env.example, TypeScript types or shell exports, and check it for the usual mistakes.

Produce a list of chosen files with sizes and dates as text, CSV, Markdown or JSON.

Plan a batch rename with find and replace, numbering and case rules, then take the script or the renamed copies.

Convert between bytes, KB, MB, GB and TB in both binary and decimal, with transfer times.

Make filenames safe across operating systems, and see exactly what was wrong with them.

Find the git command for what you are trying to do, with what it does and what it can destroy.

Break a git remote URL into host, owner and repository, and convert between SSH, HTTPS and web forms.

Build a .gitignore from language, framework, editor and operating system sections, with duplicates removed.

Compress or decompress a file with gzip or deflate, using the browser's own compression.

View any file as a hex dump with its text column, and search for bytes or text.

Escape text for safe use in HTML, or decode entities back into readable characters.

Indent messy or minified HTML so it can be read, or strip it back down to one line.

Escape text for a JavaScript string literal, including the </script> case.

Compare two JSON documents structurally, ignoring key order and formatting.

Escape text so it can be embedded safely inside a JSON string.

Format, validate and minify JSON with clear error messages that point at the exact position.

List every key path in a JSON document with its type and how often it appears.

Test a JSONPath-style query against a document and see what it matches.

Infer a draft 2020-12 JSON Schema from a sample document, with format and enum detection.

Check a JSON document against a schema and get a JSON Pointer to every value that fails.

Sort JSON object keys alphabetically at every level, leaving arrays alone.

Turn an escaped JSON string back into readable text, with or without its quotes.

Pull every value stored under a given key name, wherever it appears in the document.

Explore JSON as a collapsible tree, with node counts, depth and located errors.

Build a mailto: link with subject, body, cc and bcc, encoded so nothing truncates.

Convert Markdown to HTML or HTML back to Markdown, with a live preview.

Escape text so it is treated as a literal inside a regular expression.

Break a regular expression into pieces and explain what each one does in plain English.

Build a regular expression from tested patterns, with anchors and flags, and try it against sample text.

Pull every match out of text, with capture groups, named groups and positions.

Test a regular expression replacement with capture groups and see the result live.

Split text on a regular expression and see each resulting part, empties included.

Test a regular expression against sample text with live highlighting and capture groups.

Compare two semantic versions by precedence, including prerelease ordering and caret or tilde ranges.

Lay a query out clause by clause with keywords capitalised, or strip it back to a single line.

Bundle files into a .tar archive in your browser, with ustar headers any tar can read.

List and extract the contents of a .tar archive in your browser, with header checksums verified.

Convert between chmod octal values and rwx permissions, with the command to copy.

Indent XML to reveal its structure, or minify it back to a single line.

Bundle several files into one ZIP archive in your browser, with nothing uploaded.

Look inside a ZIP file and pull out its contents, without uploading the archive.