Read QR code images locally when browser detection is supported.

Create Code 128 Set B barcodes from printable ASCII text.

Decode common supported barcode images within your browser.

Make a compact vCard contact QR using browser-only encoding.

Test JavaScript regular expressions in a time-limited browser worker.

Compare two snippets with side-by-side line highlighting.

Reveal tabs, spaces, newlines and trailing whitespace.

Convert px, rem, em, vw and vh with configurable reference values.

Build an encoded URL query from editable name and value rows.

Calculate responsive width, height, aspect ratio and viewport units.