No. All encoding runs entirely in your browser. The text you enter, the colors you pick, and the generated PNG never leave your device, and nothing is stored on our servers.

L (~7%) gives the smallest, simplest pattern — fine for clean digital displays. M (~15%) is a balanced default for most prints. Q (~25%) suits posters or labels that may get scratched or partially covered. H (~30%) is required if you plan to overlay a logo in the center. Higher levels make the pattern denser, so increase the size if scanning becomes harder.

Three common causes — low contrast between foreground and background colors (light yellow on white scans poorly), insufficient margin (set the margin slider to at least 2), or the image is too small when printed. Try a higher size (512 px or more), keep enough quiet zone, and use dark colors on a light background.

Yes — switch the content type to "Wi-Fi" above the input box, fill in the SSID, password, and security type, and the tool will assemble the correct WIFI:T:WPA;S:...;P:...;; string for you. Most modern phones recognize this format and will prompt to join. If you prefer to write it manually, paste it in Text mode using the same format and escape any special characters with a backslash.

The theoretical maximum is roughly 2,953 bytes for binary data at error correction level L, but practical limits are much lower because higher correction levels and special characters reduce capacity. As a rule of thumb: short URLs and Wi-Fi credentials (under 200 characters) work everywhere; aim to keep payloads under 500 characters for reliable scanning. If you exceed the limit the encoder will fail — try shortening the URL with a redirect service or lowering the error correction level.

PNG at 1024 px is sharp enough for most posters, flyers, and packaging when scaled to about 2–4 cm wide. For very large prints (banners, billboards) or high-DPI offset work, use the Download SVG button — vectors scale to any size without losing sharpness and are preferred by most print shops.