Tech Stack Detector

Send HTTP requests with custom method, headers, body, and authentication — inspect the full response.

Test any URL for CORS (Cross-Origin Resource Sharing) with a custom method, headers, and body — see exactly why a browser would allow or block the request.

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).

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.