QR Generator Online
Hướng Dẫn Trợ Giúp và FAQ

Câu Hỏi Thường Gặp về Tạo và Quét Mã QR

Tìm câu trả lời đáng tin cậy về thời hạn mã QR, độ phân giải in, sửa lỗi và tùy chỉnh logo.

Create QR Code Now View Features

Frequently Asked Questions & Technical Advice

Do static QR codes expire? No, static QR codes created on QR Generator Online contain raw data and will never expire as long as your destination link remains active.

What is the best format for print? Vector SVG is the recommended format for commercial printing as it scales to any physical dimension without pixelation or quality loss.

Kiến Trúc Kỹ Thuật & Giao Thức

The Master Technical & Practical FAQ for Optical 2D Barcodes

This is the QR Generator Online knowledge base — the place to settle a technical, design, prepress, or security question about the 2D matrix barcodes defined by ISO/IEC 18004.

The answers here cover the whole span: the maths behind Reed-Solomon error correction, how a phone camera turns a photo into data, the distance-to-size ratio you print by ($S = D / 10$), and where GDPR and CCPA touch a QR workflow. Developers, marketing leads, prepress technicians, and business owners all end up needing different pieces of it.

The categories below are sorted so you can jump straight to creating, styling, printing, or deploying a code.

Technical Summary of QR Code Symbology Standards

Technical ParameterStandard SpecificationEngineering Recommendation
Governing Standard ISO/IEC 18004:2015 (Information Technology) Strict adherence for universal optical decoding
Error Correction Levels Level L (7%), Level M (15%), Level Q (25%), Level H (30%) Level H for logo embeds; Level M for clean URLs
Quiet Zone Margin Minimum 4 module widths on all 4 sides Mandatory for scanner boundary edge-detection
Optical Sizing Formula S = D / 10 (Width = Scan Distance / 10) Minimum 25 mm x 25 mm for handheld print media
WCAG Contrast Ratio Minimum 4.5:1 luminance contrast (7:1 for outdoors) Dark foreground modules on light background canvas
Maximum Data Capacity 4,296 alphanumeric / 7,089 numeric / 2,953 bytes Keep under 150 characters for rapid camera decoding

Cách Nhận Câu Trả Lời Nhanh

1

Select Data Payload Schema

Start from what you are encoding — URL, vCard 3.0, WiFi, WhatsApp, SMS, email, phone, location, event, crypto, plain text, or a Google Form.

2

Configure Styling & Error Correction

Set brand colours that stay above 4.5:1 contrast, choose a dot style, and if a logo is going in the middle, generate at Level H.

3

Export Vector SVG & Test Physical Proofs

Download the vector SVG or 4K PNG, then scan it on a few different phones under different lighting before it goes anywhere.

Các Chủ Đề Trung Tâm Trợ Giúp Này Bao Gồm

Comprehensive Technical Coverage

The error-correction maths, the URI protocols, and how camera binarization actually works — explained rather than glossed over.

Practical Prepress & Printing Guidance

Real sizing formulas, which substrate to pick, and how to compensate for ink dot gain on press.

Security & Quishing Defense Strategies

What to do so a tampered or spoofed code cannot turn your campaign into a phishing vector.

100% Free & Open-Access Knowledge Base

Open documentation that stays put — no login, no paywall, whether you are a developer or a marketer.

QR Code Resolution & Print Sizing Guide

Quick reference guide for determining physical print dimensions based on user viewing distance.

Placement / ApplicationExpected Scan DistanceMinimum Width (S)Recommended Error Correction
Business Cards & Name Tags 15 cm - 30 cm (6" - 12") 25 mm x 25 mm (1.0" x 1.0") Level Q (25%) or Level H (30%)
Table Tents & Coasters 30 cm - 50 cm (12" - 20") 35 mm x 35 mm (1.4" x 1.4") Level M (15%) or Level H (30%)
Product Packaging & Labels 20 cm - 40 cm (8" - 16") 30 mm x 30 mm (1.2" x 1.2") Level H (30%) with center logo
Flyers, Posters & Magazines 50 cm - 150 cm (20" - 60") 60 mm - 150 mm (2.4" - 6.0") Level M (15%)
Vehicle Fleet Graphics 3.0 m - 6.0 m (10 ft - 20 ft) 300 mm x 300 mm (12" x 12") Level H (30%) on cast vinyl
Highway Billboards 15.0 m - 30.0 m (50 ft - 100 ft) 1500 mm - 3000 mm (5 ft - 10 ft) Level L (7%) or Level M (15%)

Các Tình Huống Thường Được Hỏi

  • 1

    Enterprise IT & Security Compliance

    Check that a corporate QR rollout lines up with GDPR, CCPA, and ISO data-sovereignty rules before it ships.

  • 2

    Packaging Design & Flexographic Prepress

    Confirm a barcode die-line clears ISO/IEC 18004 contrast and quiet-zone limits before the plates get made.

  • 3

    Hospitality & Restaurant Chains

    Roll out contactless menus and guest WiFi cards that need no staff to explain them.

  • 4

    Event Organizers & Conference Coordinators

    Speed up check-in, hand out speaker slide downloads, and drop sessions into attendees' calendars.

  • 5

    Real Estate Brokerages & Marketing Teams

    Turn a yard sign into a round-the-clock lead source that opens a 3D virtual tour.

Top 5 Most Common QR Code Failures & How to Fix Them

  • Weak contrast. Pale modules on a pale background give the camera nothing to lock onto. Stay at 4.5:1 or higher.
  • A clipped quiet zone. Trim the margin too close and the scanner can no longer find where the code begins. Keep the full 4-module border.
  • A 72 DPI screenshot. Low-res web graphics blur at the module edges in print. Supply vector SVG or a 300+ DPI raster instead.
  • Too much data. A long URL packs the matrix with tiny dots that smear when printed small. Shorten the link before you generate.
  • Glossy lamination. A high-gloss coat throws spotlights back into the lens. Ask for matte or satin.

Câu Hỏi Thường Gặp

Mọi thứ nhà phát triển, nhà tiếp thị và chủ doanh nghiệp cần biết.

What is the difference between a static and a dynamic QR Code?
A static code carries the actual data — the URL, vCard, WiFi string, whatever it is — inside the matrix. Nothing to expire, no server to depend on. A dynamic code carries a redirect that points at someone else's server, which lets you edit the destination later but ties you to a subscription to keep the redirect alive.
Do QR codes created on QR Generator Online ever expire?
They stay valid for life. Unlimited scans, no recurring fee, no timer counting down — the code is self-contained.
What is the minimum physical size a QR code can be printed?
For a short URL read from 15-20 cm away, 20 mm x 20 mm (0.8" x 0.8") is the floor. On packaging and business cards, treat 25 mm x 25 mm (1.0" x 1.0") as the safe industry minimum.
How does Error Correction Level H protect my QR code with a logo?
Level H duplicates roughly 30% of the payload through Reed-Solomon redundancy. That spare copy is what lets a logo sit over the centre modules — the scanner reconstructs the covered data from the redundant bits.
Can I customize QR code colors to match my brand identity?
You can recolour the modules, the background, the corner frames, and the corner dots independently. One rule governs all of it: dark against light needs to clear 4.5:1 contrast, or scanners start to struggle.
Why is SVG format recommended over PNG for commercial printing?
SVG describes the code as geometry, not pixels. Enlarge it from a business card to a billboard and the edges stay razor-sharp, because there is no pixel grid to run out of.
Are QR codes safe from malware and phishing ("quishing")?
The code itself only holds text or a URL — it cannot carry malware. The risk is a spoofed code pointing somewhere it should not. Guard against it by showing your verified logo in the centre and printing the real destination domain in plain text beside the code.
Is my personal data stored or tracked on QR Generator Online servers?
It is not. Everything runs client-side in browser memory. Your links, passwords, contact cards, and uploaded logos are never sent to a server or kept anywhere.

Danh Sách Kiểm Tra Khắc Phục Sự Cố

Hold contrast above 4.5:1, protect the 4-module quiet zone, and export vector SVG for print. Then scan a physical proof before the volume run — that final check is what separates a clean launch from a reprint.

Tất Cả 22 Trình Tạo Mã QR

Khám phá tất cả 22 trình tạo mã QR chuyên dụng để chuyển đổi trang web, WiFi, vCard, tài liệu, mạng xã hội, liên kết thanh toán và vị trí thành mã có thể quét được.

URL

Chuyển hướng đến một liên kết web hiện có

Tài Liệu PDF

Liên kết hoặc tải lên thực đơn, tờ rơi hoặc danh mục PDF

Văn Bản Thuần

Mã hóa văn bản thuần thành mã QR

Liên Hệ

Chia sẻ thông tin liên hệ ngay lập tức

WiFi

Chia sẻ thông tin đăng nhập WiFi qua mã QR

Email

Tạo mã QR email đã điền sẵn

SMS

Tạo mã QR SMS đã điền sẵn

Điện Thoại

Thực hiện cuộc gọi chỉ với một lần quét

WhatsApp

Bắt đầu cuộc trò chuyện WhatsApp

Mạng Xã Hội

Liên kết đến hồ sơ mạng xã hội của bạn

Vị Trí

Chia sẻ một vị trí trên bản đồ

Sự Kiện

Tạo mã QR sự kiện lịch

Crypto

Chia sẻ địa chỉ thanh toán tiền điện tử

Google Form

Liên kết đến khảo sát Google Form

Instagram

Chia sẻ hồ sơ Instagram của bạn

YouTube

Liên kết đến kênh hoặc video YouTube của bạn

LinkedIn

Chia sẻ hồ sơ LinkedIn của bạn

Twitter / X

Chia sẻ hồ sơ Twitter/X của bạn

TikTok

Chia sẻ hồ sơ TikTok của bạn

Telegram

Chia sẻ hồ sơ hoặc nhóm Telegram của bạn

PayPal

Chấp nhận thanh toán PayPal qua mã QR

UPI

Chấp nhận thanh toán UPI (Ấn Độ)

Nền Tảng Ưu Tiên Quyền Riêng Tư: Mã QR tĩnh được tạo 100% cục bộ trong trình duyệt của bạn. Chiến dịch động được quản lý an toàn với định tuyến mã hóa.

An Toàn · Toàn Cầu · Nhanh  —  Được tin dùng bởi hàng nghìn người dùng. Không cần tài khoản.

Sẵn Sàng Tạo Hướng Dẫn Trợ Giúp và FAQ Của Bạn?

Bắt đầu tạo Mã QR chuyên nghiệp, có thể tùy chỉnh trong vài giây. Không cần tài khoản, không phí — mãi mãi.

Tạo Hướng Dẫn Trợ Giúp và FAQ — Miễn Phí

Không cần đăng ký • Mã QR Không Giới Hạn • Tải xuống dạng PNG, SVG, WebP

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