QR Code Generator (PNG & SVG)

Unlike linear 1D barcodes that encode data across a single horizontal axis, a QR code is a two-dimensional matrix symbol consisting of square modules arranged in an overall square grid. The specification defines 40 discrete symbol versions, ranging from Version 1 ($21 \times 21$ modules) up to Version 40 ($177 \times 177$ modules). Each successive version adds 4 modules per side: $\text{Dimension} = 21 + 4 \times (V - 1)$.

Every compliant QR code contains standardized functional patterns that must never be obscured: • Finder Patterns: The three prominent concentric square targets located at the top-left, top-right, and bottom-left corners. With a module ratio of 1:1:3:1:1, they allow camera software to detect the code's physical location, size, and 360-degree rotational orientation instantly. • Timing Patterns: Alternating dark and light modules running horizontally and vertically between the finder patterns on row 6 and column 6, establishing the coordinate grid system. • Alignment Patterns: Sub-targets placed in regular intervals across larger QR codes (Version 2 and higher) to correct for perspective distortion when scanning curved surfaces (such as beverage cans or wrinkled paper). • Format Information: Redundant bits adjacent to finder patterns encoding the error correction level and mask pattern index, protected by BCH(15,5) error-correcting codes.

The defining engineering breakthrough of the QR code is its remarkable resistance to dirt, smudges, tears, and physical occlusion, achieved through Reed-Solomon cyclic polynomial error correction. When data is encoded, the engine calculates Galois Field $GF(2^8)$ error-correction codewords that are interleaved throughout the bitstream.

Our generator supports all four ISO-standardized Error Correction Levels (ECL): • Level L (Low): Recovers up to ~7% of corrupted or occluded data codewords. Offers the highest data capacity and smallest physical matrix size; ideal for clean digital displays. • Level M (Medium): Recovers up to ~15% of corrupted data. The industry default, providing an optimal balance between density and reliability for general marketing. • Level Q (Quartile): Recovers up to ~25% of corrupted data. Recommended for high-wear environments, outdoor street posters, and industrial factory floors. • Level H (High): Recovers up to ~30% of corrupted data. Recommended for high-wear environments or outdoor signage, ensuring the code scans reliably even if partially obscured or smudged.

To maximize data storage within the smallest possible matrix version, the QR code specification defines four primary data encoding modes: • Numeric Mode: Encodes digits 0–9 by packing triplets of decimal digits into compact 10-bit binary words (max 7,089 characters in Version 40-L). • Alphanumeric Mode: Encodes 45 characters (digits, uppercase letters A–Z, and 9 special punctuation symbols: space, `$`, `%`, `*`, `+`, `-`, `.`, `/`, `:`) by packing pairs of characters into 11-bit words (max 4,296 characters). • Byte Mode: Encodes raw 8-bit binary data (such as UTF-8 text, URLs, and multi-byte unicode characters) with 8 bits per character (max 2,953 bytes). • Kanji Mode: Encodes Shift-JIS double-byte characters into 13-bit words (max 1,817 characters). Our generator automatically analyzes your input text and selects the most compact encoding mode, preventing unnecessary grid complexity and keeping module dots comfortably large for effortless camera scanning.

If a raw QR bitstream contains large clusters of identical dark or light modules (or inadvertently mimics the 1:1:3:1:1 ratio of a finder pattern), optical camera sensors lose tracking synchronization. To prevent this, the ISO specification mandates that the encoded matrix undergo mathematical masking.

The engine evaluates eight standardized mask patterns (Patterns 0 through 7) by applying a bitwise XOR operation against matrix coordinates (e.g. Mask 0: $(x + y) \pmod 2 == 0$; Mask 3: $(x + y) \pmod 3 == 0$). The masked matrices are scored against four penalty rules that penalize long runs of identical modules, $2 \times 2$ blocks, and pseudo-finder sequences. Our engine evaluates all eight masks and automatically deploys the optimal mask with the lowest penalty score.

Modern brand marketing demands visually engaging QR codes that match your brand identity while maintaining flawless optical readability. Our tool provides streamlined design customization while safeguarding ISO compliance: • Curated Color Palettes: Select from designer color presets (Midnight Navy, Forest Emerald, Royal Indigo, Deep Crimson) or configure custom hex foreground and background colors, including transparent backgrounds for overlays. • High-Contrast Luminance: Optical camera sensors require strong contrast between dark modules and light backgrounds. Our generator ensures high luminance contrast so your codes scan instantly in dim ambient lighting or bright sunlight. • Quiet Zone Margins: Customize quiet zone margins (0 to 4 modules) to guarantee smartphone camera algorithms isolate the matrix reliably against busy backgrounds.

Our tool features curated schema generators for the most popular real-world QR use cases: • Wi-Fi Network Access: Formats standard `WIFI:S:MyNetwork;T:WPA;P:Password123;;` strings, allowing guests to join secured Wi-Fi networks by simply pointing their camera at the code. • Digital Contact Cards (vCard 3.0): Formats full `BEGIN:VCARD` records containing names, job titles, phone numbers, email addresses, and website links for seamless mobile address book import. • URLs & Deep Links: Encodes direct web addresses, app store download links, and social profile links. • Cryptocurrency Payments: Formats Bitcoin (`bitcoin:address?amount=...`), Ethereum, and Solana URI schemas for instant digital payments.

Generating QR codes for sensitive office Wi-Fi passwords, private executive phone numbers, crypto wallet addresses, or confidential internal portal URLs should never involve sending your plaintext data to remote cloud servers. Traditional 'free online QR generators' routinely log, catalog, and monetize submitted data.

Our QR Code Generator executes 100% locally inside your web browser. Built entirely in client-side TypeScript with zero external server dependencies, all matrix construction, polynomial division, and image rendering take place in device RAM. No data ever leaves your computer, ensuring complete data security and total compliance with GDPR, HIPAA, and corporate security guidelines.