QR Code Reader &
Metadata Inspector
Upload an image or use your camera — instantly decodes the content, detects the type (URL, WiFi, vCard, SMS…), and shows the QR's technical metadata. Everything runs in your browser; nothing is uploaded.
How it works
jsQR parses raw pixel data in your browser to find and decode the QR matrix — nothing leaves your device.
Each QR version adds 4 modules per side. V1 = 21×21 modules (minimum). V40 = 177×177 modules (maximum). Higher versions hold more data but need higher print resolution.
Reed-Solomon error correction recovers damaged codewords: L=7%, M=15%, Q=25%, H=30%. Logos on QR codes need H so the covered modules can be reconstructed.
Numeric (digits only) is most compact. Alphanumeric adds A–Z and symbols. Byte handles UTF-8 text (used for URLs and messages). Kanji handles Japanese Shift-JIS characters efficiently.
The tool inspects the decoded text for known prefixes: http/https, WIFI:, BEGIN:VCARD, mailto:, sms:, tel:, geo:, BEGIN:VEVENT. Each type gets a dedicated panel.
Frequently asked questions
- What QR code types does this tool detect?
- The tool automatically identifies: URLs (with safety analysis), WiFi credentials (SSID, password, security type), vCard contacts (name, phone, email, org), email (mailto:), SMS, phone numbers (tel:), geo locations, calendar events (VEVENT), cryptocurrency addresses, and plain text. Each type gets a dedicated breakdown panel.
- Is it safe to scan a QR code I found online?
- QR codes can encode any URL, including malicious ones. This tool decodes the content and flags common red flags: raw IP addresses as the domain, non-standard ports, HTTP (unencrypted), suspicious TLDs (.xyz/.tk/.cf), hostnames with too many segments (subdomain hijacking), and known brand names appearing in subdomains rather than the root domain. These are heuristic signals — always inspect the full URL before visiting, especially for financial or login pages.
- What do version and error correction level mean?
- The version (1–40) defines the physical grid size of the QR code. Version 1 is 21×21 modules; each step up adds 4 modules per side. Most everyday QR codes (payments, social links) are Version 3–7. The error correction level determines how much of the code can be damaged while still scanning: L=7%, M=15% (default), Q=25%, H=30%. Logo QR codes typically use Q or H to compensate for the logo covering part of the data.
- Why can't the tool read my QR code?
- jsQR requires the QR code to be clearly visible and well-lit. Common failure causes: the image resolution is too low, the code is rotated or at a steep perspective angle, heavy JPEG compression artifacts obscure the finder patterns, or the QR code is too small relative to the overall image. Try cropping the image so the QR code fills most of the frame, or use a higher-DPI scan. The camera option can help when you can position a physical code in good light.
- How do I read a WiFi QR code to get the password?
- WiFi QR codes use the format
WIFI:T:WPA;S:NetworkName;P:password;;. This tool parses that format and shows the network name (SSID), password (with a toggle to reveal it), and security type (WPA/WPA2/WEP/open). You can then copy the password directly from the results panel.