The complete guide to QR codes: types, design, printing, and UPI payments
QR codes — those square, pixelated patterns — have quietly become one of the most useful bridges between the physical and digital worlds. A single scan can open a website, connect a guest to your WiFi, save a contact to a phone, start a WhatsApp chat, or even complete a payment. Yet most free QR generators only scratch the surface: they make a plain black-and-white code for a URL and stop there. Scanova was built to cover the full spectrum — from everyday URL codes to UPI payment QR codes, WiFi credentials, vCards, WhatsApp links, styled codes with your logo, and even free batch generation for when you need dozens of codes at once.
How QR codes actually work
A QR code is simply encoded text rendered as a pattern of dark and light modules. The three large squares in the corners — the finder patterns — tell the scanner where the code begins and how it is oriented, which is why a QR code scans at any angle. The data itself is protected by Reed–Solomon error correction, the same mathematical technique used on scratched CDs. Depending on the error-correction level chosen, between 7% and 30% of the code can be damaged, dirty, or covered up and the code will still scan perfectly. This is the property that makes logo overlays possible: the logo covers part of the pattern, and error correction fills in the gaps.
There are two broad families of QR codes. Static QR codes encode the destination directly — the URL, text, or payment link lives inside the pattern itself, so the code works forever and needs no server. Dynamic QR codes encode a short redirect link hosted by a service, which lets you change the destination later and track scans, but requires a paid subscription and means the service could shut down your codes. Scanova generates static QR codes: they never expire, need no account, and cannot be switched off by anyone but you.
The QR content types that matter most
URL and text. The classics. A URL code should open fast — use the shortest link you can, since shorter content produces a less dense, easier-to-scan pattern. Always test-scan before printing; a surprising number of printed codes fail because of typos that nobody checked.
WiFi. A WiFi QR code encodes your network name, password, and encryption type in a special format (WIFI:T:WPA;S:MyNetwork;P:secret;;). Guests point their camera at the code and their phone offers to join the network — no more dictating long passwords or watching typos. Cafés, Airbnb hosts, offices, and event venues get the most mileage from this type. Special characters in the password are automatically escaped so the code stays valid.
vCard. A vCard QR code stores contact details in the vCard format that phones understand. Scan it and the phone opens a new contact pre-filled with name, phone number, email, organisation, and website. It is the digital successor to the business card — stick one on your card, email signature, or conference badge and people save your details in one tap instead of typing them.
WhatsApp. A WhatsApp QR encodes a wa.me link with your phone number and an optional pre-filled message. Small businesses use these for "chat with us" stickers, customer support desks, and order-taking: the customer scans, WhatsApp opens with a greeting already typed, and the conversation starts.
Email, SMS, phone, and location. These small presets open the right app with fields pre-filled: an email QR can set the recipient, subject, and body; an SMS QR pre-fills the number and message; a phone QR opens the dialer; a location QR drops a map pin at your coordinates. Each is a tiny convenience that removes a step between a customer's intention and action.
UPI payment QR codes: a game-changer for India
In India, the QR code found its killer use case: instant payments. A UPI QR code encodes a payment instruction in the format upi://pay?pa=yourname@bank&pn=YourName&am=100&cu=INR. When a customer scans it with Google Pay, PhonePe, Paytm, BHIM, or any UPI app, the payment screen opens with your UPI ID, name, and amount already filled in — the customer just enters their UPI PIN. No card machine, no payment gateway fees, no hardware at all.
Two flavours exist. An open-amount QR leaves the amount blank so the payer types it — perfect for a shop counter or a donation box where every bill differs. A fixed-amount QR locks in a specific rupee value, which is ideal for invoices, fees, tickets, and menu items where the price is known in advance. Scanova's UPI preset supports both: leave the amount empty for open payments, or set it for fixed ones, and optionally add a transaction note that appears in the payer's app.
UPI QR codes work for far more than retail. Freelancers put them on invoices to get paid faster. Landlords stick them on rent receipts. Event organisers use fixed-amount codes for ticket sales. Restaurants print table-specific codes so bills are settled at the table. Because the upi://pay format is an open NPCI standard, a code you generate works in every UPI app — you are never locked to one provider. And since Scanova builds the code entirely in your browser, your UPI ID is never sent to any server.
Designing QR codes that stay scannable
A pretty QR code that does not scan is a failure, so design rules matter. The golden rule is contrast: the dark modules must stand out clearly against the background. Dark-on-light works; light-on-dark often fails because many scanners look for dark finder patterns on a light field. Avoid inverting your colours, and keep the contrast ratio high — deep indigo on white is safe, pastel pink on cream is not.
The second rule concerns logos. Place the logo in the centre, keep it modest (Scanova defaults to 22% of the code width and caps it at 35%), never cover the three corner squares, and raise error correction to level H. Scanova does the last step automatically the moment you upload a logo. Test the finished code with two different phones — an iPhone camera and one Android camera app — before you print hundreds of copies.
The third rule is quiet zone: the blank margin around the code. Scanners need that breathing room to find the code's edges. Four modules of margin is the standard; Scanova gives you a slider from zero to eight so you can match any layout, but keep at least the default unless you know the surrounding design provides the margin for you.
Print sizes, formats, and materials
For anything printed, resolution is everything. A useful rule of thumb: the code should be at least 2 × 2 cm for close-range scanning (business cards, product labels) and roughly 10 cm of code width per metre of scanning distance (posters, banners, shop windows). Scanova's PNG export goes up to 2048 pixels for crisp print, and the SVG export is vector — it scales to billboard size without a single jagged edge.
Material matters too. Matte surfaces scan more reliably than glossy ones because glare can wash out the pattern. If the code lives outdoors, laminate it or print on weatherproof stock — sun-faded codes are a common failure. On curved surfaces like bottles or mugs, keep the code small enough that it does not wrap too far around the curve, since distortion hurts readability. And always leave the code flat: a crease through the middle of a folded flyer can be enough to break it.
Batch QR codes: when you need dozens, not one
Some jobs need QR codes in bulk: product serial numbers, table tent cards for a restaurant, asset tags for an office inventory, attendee badges for a conference, or per-invoice UPI payment links. Most free generators make you create each code one by one, and bulk features are usually locked behind business plans. Scanova's batch mode takes a pasted list — one item per line — and generates a separate downloadable code for each, up to 50 per batch. Each batch code downloads individually as PNG or SVG, so you can drop them straight into a label template or print run.
QR security: scan smart
A few honest cautions apply to every QR tool, including this one. Never encode a QR code from a link you do not trust — malicious codes can lead to phishing sites. If you receive a payment QR, verify the payee name shown in your UPI app before entering your PIN; scammers sometimes swap QR stickers on shop counters. For your own codes, prefer static codes for anything permanent (printed menus, signage) since they cannot be hijacked by a redirect service going rogue. And remember that anything encoded in a QR — including WiFi passwords — is readable by anyone who can see the code, so do not post your home WiFi QR publicly.
Privacy is the other half of the story. Many online generators upload your content to their servers to create the image. Scanova does all encoding and rendering locally in your browser with the open-source qrcode-generator library — your text, contacts, WiFi passwords, and UPI IDs never leave your device. There is no account, no tracking, and no database of your codes.
Getting the most out of Scanova
Start with the content card: choose the type that matches your goal, fill in the fields, and watch the preview update live. Then style it — match the colours to your brand, upload your logo for the centre, and pick a PNG size suited to where the code will live (512 px for screens, 1024–2048 px for print). Download the SVG as well: it is the master copy you will thank yourself for when a designer later asks for the code at poster size. If you need many codes, switch to batch mode and paste your list. Everything is free, unlimited, and watermark-free — the only limit is your imagination for where a scan can take someone.