Curl

Encode UTF-8 text as Base64, or decode Base64 to UTF-8 text.

Percent-encode arbitrary text for safe inclusion in URLs, or decode percent-encoded text.

Escape HTML special characters as entities (& < > "), or decode entities to plain text.

Pretty-print, minify, or sort-key JSON.

Fetch a URL and inspect response headers, status code, and redirect chain.

Compute a unified diff between two blocks of text (line-based).

Send a CORS preflight + GET to a URL and inspect Access-Control-* headers; flags common misconfigurations.

Break a URL into its components (scheme, host, port, path, query params, fragment) or assemble one from parts.

Test a regular expression against a string — shows all matches, captured groups, and highlights matches inline.

Translate a cron expression into next 8 scheduled run times (UTC). Supports 5-field and 6-field (with seconds) syntax.

Convert between HEX, RGB, and HSL color notations with a preview swatch.

Fetch a URL and preview how it appears as a Google result, Twitter card, and Open Graph share.

Given width, height, or a W:H ratio, calculate the missing dimension and show the simplified ratio.

Fetch an image URL and convert it to a Base64 data URI for embedding directly in CSS or HTML.

Load a URL in headless Chromium, extract every computed CSS color, and list them as a sortable palette with swatches.

Load a URL in headless Chromium and identify the CSS frameworks, JS frameworks, analytics, CDNs, CMS, and hosting platform used to build the site.

Estimate entropy of a candidate password and classify weak/fair/strong.

RFC 5322 syntax check on an email address, plus an MX-record existence probe on its domain.

Count characters, words, lines, paragraphs, plus an estimated reading time.

Fetch a site's robots.txt, list its rule groups + sitemaps, and validate whether a specific path is allowed for a given user agent.