Developer Tools

Pretty-print, minify, and validate JSON in your browser. Nothing is uploaded.

Generate UUID v4 or v7 identifiers — one, or a list to copy and download.

Test a JavaScript regular expression against sample text. See matches, groups, and positions.

Make a random password in this browser. Nothing is stored or sent.

Encode text as Base64, or decode it back — useful for data URLs and text channels.

Encode or decode text so it sits safely in a query string.

Switch between a Unix timestamp and a readable date.

SHA hashes of text, calculated in this browser.

Read a JWT header and payload. The signature isn't checked — this is a decoder, not a verifier.

Check that a JSON document parses, and see the line if it doesn't.

Break a SQL statement onto readable lines so you can actually scan it.

Indent an XML document so the structure is easier to see.

Build a five-field cron expression and a plain-language reading of when it runs.

Escape HTML characters, or turn the escapes back into text.

Pretty-print JSON, or indent a brace-style snippet.

Turn a JSON array of objects into a CSV table you can copy.

Infer a readable JSON Schema from a JSON document you paste.

Estimate password strength in this browser. Nothing is sent anywhere.

Parse raw email headers into sender, routing, dates, and SPF/DKIM/DMARC tokens.

Estimate how much of a model’s context window a prompt and reply would use.

Estimate per-request, daily, and monthly token cost from published prices you can check.

Turn a CSV table into a JSON array of objects.

Check a YAML document and show the first problem we find.

Convert straightforward YAML into JSON.

Write a robots.txt from the paths you allow and block.

Tick permissions and get the octal mode and the symbol form.

See the network, broadcast, and usable hosts for an IPv4 prefix.

Read an address/prefix and show the network it belongs to.

Try a JSONPath against a JSON document and see what matches.

Assemble a Content-Security-Policy header from the sources you allow.

Add campaign parameters to a URL so you can tell where a visit came from.

Turn a short description into a conventional commit.

Whether a request limit covers the users you expect.

A short quiz with Cursor, Claude Code, or Copilot as the read.