Browser-only PNG output
QR Code Generator
Create a fixed 512×512 PNG QR code from exact text or an HTTP(S) URL without sending the payload to a QR-generation server.
Generated result
No QR code generated
Select a mode, enter a payload, and generate explicitly. Nothing is generated on page load.
Exact text and URL encoding
Text mode preserves the accepted string exactly, including leading and trailing spaces, internal whitespace, line breaks, case, and Unicode. For example, two entered lines remain two encoded lines.
URL mode accepts only complete HTTP or HTTPS URLs with a host. Parsing validates syntax and scheme; it does not normalize, shorten, redirect, host, verify, or track the destination.
The 1,024-byte limit measures UTF-8 bytes rather than JavaScript character count. Unicode characters can use more than one byte.
Output and scan limits
The encoder chooses the QR version and mask automatically, then creates a black-on-white 512×512 PNG with error correction M and a four-module quiet zone.
Error correction M can tolerate some damage but does not guarantee scanning. Device, scanner application, payload length, display size, contrast, print quality, focus, and lighting all affect results.
Printing or resizing may reduce readability. Scan-test the downloaded code with intended devices before publishing or distributing it.
Privacy and destination safety
QR encoding occurs in your browser. The entered text or URL is not sent to a QR-generation server by this tool.
Calzivo does not control what happens after a scanner opens an encoded URL. Verify destination URLs before sharing them and remember that a destination can later change.
The generated PNG contains the payload in QR form. Anyone who receives the image may be able to decode it.
Worked examples and common failures
Text: enter Calzivo QR test. URL: enter https://example.com/path?q=hello. The exact accepted input becomes the QR payload.
Whitespace-only text, URL whitespace, bare domains, relative URLs, non-HTTP schemes, malformed URLs, and payloads above 1,024 UTF-8 bytes are rejected.
If scanning fails, use the original PNG, avoid cropping its white quiet zone, increase its physical size, preserve contrast, and test under realistic lighting.
Frequently asked questions
Does Calzivo host or shorten the URL?
No. The exact validated URL is encoded locally without hosting, shortening, redirection, or tracking.
Is scanning guaranteed?
No. Scanner support and real-world conditions vary, so test the final downloaded or printed code.
What does error correction M mean?
It adds recovery information for some damage, but it cannot guarantee that every scanner or damaged code will work.
Why can Unicode reach the limit sooner?
The limit is measured after UTF-8 encoding, where many Unicode characters require multiple bytes.
Sources and related tools
Implementation and QR construction details are based on the node-qrcode documentation and DENSO WAVE QR Code guidance.