QR Code Generator

Why the QR Code Gets Denser as You Type More

A QR code's grid isn't a fixed size — the underlying spec defines 40 "versions," from a 21×21-module grid up to 177×177 modules, and the encoder automatically picks the smallest version that fits your data plus your chosen error correction overhead. That means the exact same physical print size holding a 200-character URL will have noticeably finer, denser modules than one holding a 20-character URL, and denser modules are harder for a phone camera to resolve at a distance or when printed small. If a QR code is destined for a business card or a product label, keep the encoded string short — a URL shortener buys you real scannability margin, not just a tidier-looking link.

The four error correction levels (L/M/Q/H, corresponding to roughly 7%/15%/25%/30% of the code's data that can be reconstructed if damaged) are a direct trade-off against that same density: higher error correction adds redundant data to the same content, which pushes the encoder toward a larger version and denser grid for identical input. Choose L only for clean digital display where nothing will obscure the code; choose Q or H when the code will be printed small, laminated, exposed to wear, or will have a logo overlaid on the center (a common design technique that relies on the code tolerating that "damage").

The WiFi and Contact Templates Follow Real, Picky Specs

The "WiFi" template produces a string in the format WIFI:T:WPA;S:NetworkName;P:Password;; — this isn't an arbitrary format invented for this tool, it's the de facto standard most phone camera apps recognize for auto-joining a network. The catch: if your actual network name or password contains a semicolon, comma, colon, or backslash, that character must be escaped with a backslash (\;, \,, \:, \\) or the scanner will misparse the field boundaries and either fail or join the wrong network. This tool doesn't auto-escape those characters for you — check the generated string manually if your SSID or password uses punctuation.

The "Contact" template generates a vCard 3.0 block (BEGIN:VCARD ... END:VCARD). Every field is optional except BEGIN, VERSION, and END, but omitting FN (formatted name) causes some contact apps to import a nameless entry. If you need fields the built-in template doesn't include — a postal address (ADR) or a job title (TITLE) — you can edit the generated text directly in the input box before generating; the vCard spec tolerates extra recognized fields appended before END:VCARD.

PNG vs. SVG Export — and a Contrast Warning

The PNG download captures the rendered canvas exactly as sized on screen (100-500px per the size slider) — fine for web use, but it will look blocky if you scale it up significantly for large-format printing. The SVG download instead regenerates the code as vector paths from your same settings, so it scales to any print size (a banner, a poster) with perfectly crisp edges. If you're printing anything larger than a business card, use SVG.

Custom colors are purely cosmetic to this tool, but not to a scanner: QR decoding depends on contrast between the "dark" and "light" modules, not on any particular hue. Two colors that are visually distinguishable to a person (say, a mid-blue on a light-gray background) can have too little luminance contrast for a camera's binarization step, causing scan failures that never show up when you're just eyeballing the preview. If you customize colors, test-scan the actual output with a phone before printing at volume.

Frequently Asked Questions