How QR codes work

A QR code is more than a black-and-white grid. Its modules carry orientation targets, format metadata, encoded payload bits, padding, and Reed–Solomon error correction. Configure a symbol, then hover or focus any module to see its role. Click, tap, or press Enter to pin a selection.

Configure

Reset

Datahttps://qrcodesdk.dev

UTF-8 ECI

Emit assignment 26 before the first octet segment to explicitly declare UTF-8.

ModeAuto

VersionAuto

Error CorrectionAuto

MaskAuto

Size

Margin

V2 octet ECC M Mask 2 25×25 modules

Signal map

QR anatomy

Hover to preview · click to pin

Quiet zone 464 Finder pattern 147 Finder separator 45 Timing pattern 18 Alignment pattern 25 Format information 30 Dark module 1 Mode indicator 4 Character count 8 Payload data 168 Terminator 4 Padding 40 Error correction 128 Remainder bits 7

Inspect a module

Hover any square to reveal its job. Click, tap, or press Enter to keep a selection pinned while you explore.