Online Tools

Generate QR codes for URLs, Wi-Fi, email or phone in your browser. Real Reed-Solomon encoder, 4 error correction levels, PNG download. Nothing uploaded.

Convert YAML to JSON and back in your browser. Clear errors on anchors, tags and multi-doc files instead of silent mangling, plus honest notes on YAML footguns.

Convert JSON to CSV and CSV back to JSON in your browser. Real RFC 4180 parser, nested object flattening, delimiter choice, type inference. Nothing uploaded.

Convert decimal, hex, binary, octal and any base 2 to 36 live as you type. BigInt handles huge integers exactly, with a two's complement view. In-browser.

Free case converter that splits camelCase boundaries correctly. Switch between 11 cases including snake_case, PascalCase and Title Case, all in your browser.

Count words, characters, sentences and reading time live as you type. Keyword density plus X, SMS and meta description limits. Runs entirely in your browser.

Compare two texts line by line in your browser. Real LCS diff with ignore case and whitespace options, line numbers, stats and a copyable unified diff. Nothing is uploaded.

Generate strong passwords or passphrases locally with crypto.getRandomValues, real entropy in bits and zero server calls. Free, no signup, copy in one click.

Searchable Linux errno reference. Look up any errno by number or symbolic name (EPERM, ENOENT, EACCES, ECONNREFUSED and more), with the meaning, real causes and how to diagnose and fix...

Free local WCAG color contrast checker. Pick foreground and background, get the exact contrast ratio with PASS/FAIL badges for AA, AAA and UI components, plus a suggest-a-passing-shade fixer.